2013年CIE剑桥国际考试IGCSE数学真题答案(43)

合集下载

九天国际教育GCSE真题June 2013 (v3) QP - Paper 3 CIE Chemistry IGCSE

READ THESE INSTRUCTIONS FIRSTWrite your Centre number, candidate number and name on all the work you hand in.Write in dark blue or black pen.You may use a pencil for any diagrams, graphs or rough working.Do not use staples, paper clips, highlighters, glue or correction ﬂ uid.DO NOT WRITE IN ANY BARCODES.Answer all questions.Electronic calculators may be used.A copy of the Periodic Table is printed on page 12.You may lose marks if you do not show your working or if you do not use appropriate units.At the end of the examination, fasten all your work securely together.The number of marks is given in brackets [ ] at the end of each question or part question.CHEMISTRY0620/33Paper 3 (Extended)May/June 20131 hour 15 minutesCandidates answer on the Question Paper.No Additional Materials are required.UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certiﬁ cate of Secondary EducationThis document consists of 11 printed pages and 1blank page.[Turn overIB13 06_0620_33/2RP © UCLES 2013*6258911381*For1S ubstances can be classiﬁ ed as:Examiner’sUseelements mixtures compoundsE lements can be divided into:metals non-metals(a)D eﬁ ne each of the following terms.(i)e lement.................................................................................................................................... (2)(ii)c ompound.................................................................................................................................... (2)(iii)m ixture.................................................................................................................................... (1)(b)C lassify each of the following as either an element, compound or mixture.(i)b rass (1)(ii)c arbon dioxide (1)(iii)c opper (1)(c)W hich physical property is used to distinguish between metals and non-metals?I t is possessed by all metals but by only one non-metal. (1)[Total: 9]© UCLES 20130620/33/M/J/13For2O ne of the factors which determine the reaction rate of solids is particle size.Examiner’sUse(a)A mixture of ﬁ nely powdered aluminium and air may explode when ignited.A n explosion is a very fast exothermic reaction. This causes a large and sudden increasein temperature.E xplain each of the following in terms of collisions between reacting particles.(i)W hy is the reaction between ﬁ nely powdered aluminium and air very fast?.................................................................................................................................... (2)(ii)E xplain why for most reactions the rate of reaction decreases with time..................................................................................................................................... (2)(iii)S uggest an explanation why the rate of reaction in an explosion could increase rather than decrease with time......................................................................................................................................................................................................................................................................... (3)(b)(i)G ive another example of a substance other than a metal which, when ﬁ nelypowdered, might explode when ignited in air. (1)(ii)D escribe a simple test-tube reaction which shows the effect of particle size on the rate at which a solid reacts with a solution......................................................................................................................................................................................................................................................................... (3)[Total: 11]© UCLES 2013[Turn over0620/33/M/J/130620/33/M/J/13© UCLES 2013ForExaminer’sUse3I ron from the blast furnace is impure. It contains 5% of impurities, mainly carbon, sulfur, silicon and phosphorus. Almost all of this impure iron is converted into the alloy, mild steel.(a) (i) S tate a use of mild steel. (1)(ii) N ame and give a use of another iron-containing alloy.name ..........................................................................................................................use (2)(b) T he oxides of carbon and sulfur are gases. The oxides of silicon and phosphorus are not.Explain how these impurities are removed from the impure iron when it is converted into mild steel............................................................................................................................................ ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... (5)[Total: 8]4G ermanium is an element in Group IV. The electron distribution of a germanium atom is 2 + 8 + 18 + 4. It has oxidation states of +2 and +4.(a) G ermanium forms a series of saturated hydrides similar to the alkanes.(i) D raw the structural formula of the hydride which contains three germanium atomsper molecule.[1](ii) P redict the general formula of the germanium hydrides. (1)0620/33/M/J/13© UCLES 2013[Turn overFor Examiner’sUse(b) D raw a diagram showing the arrangement of the valency electrons in one molecule ofthe covalent compound germanium(IV ) chloride, GeC l 4.Use o to represent an electron from a chlorine atom.Use x to represent an electron from a germanium atom.[2](c) D escribe the structure of the giant covalent compound germanium(IV ) oxide, GeO 2.I t has a similar structure to that of silicon(IV ) oxide............................................................................................................................................ ........................................................................................................................................... (3)(d) I s the change GeC l 2 to GeC l 4 reduction, oxidation or neither? Give a reason for your choice............................................................................................................................................ (2)[Total: 9]5A ll metal nitrates decompose when heated. A few form a nitrite and oxygen. Most form the metal oxide, oxygen and a brown gas called nitrogen dioxide.(a) (i) N ame a metal whose nitrate decomposes to form the metal nitrite and oxygen. (1)(ii) C omplete the equation for the action of heat on lead(II ) nitrate.......Pb(NO 3)2 → ......... + ......NO 2 + O 2 [2](iii) S uggest why the nitrate of the metal, named in (a)(i), decomposes less readily thanlead(II ) nitrate..................................................................................................................................... (2)0620/33/M/J/13© UCLES 2013For Examiner’sUse(b) A lmost all samples of nitrogen dioxide are an equilibrium mixture of nitrogen dioxide,NO 2, and dinitrogen tetroxide, N 2O 4.forward reactionreverse reactionN 2O 4(g)colourless2NO 2(g)dark brownI n the forward reaction, a bond forms between the two nitrogen dioxide molecules.NO 2 + NO 2 → O 2N – NO 2(i) E xplain the term equilibrium mixture ..................................................................................................................................... .............................................................................................................................. [1] (ii) T he syringe contains a sample of the equilibrium mixture. The plunger was pulledback reducing the pressure.H ow would the colour of the gas inside the syringe change? Give an explanation foryour answer..................................................................................................................................... .................................................................................................................................... .............................................................................................................................. [3] (iii) A sealed tube containing an equilibrium mixture of nitrogen dioxide and dinitrogentetroxide was placed in a beaker of ice cold water. T he colour of the mixture changed from brown to pale yellow.I s the forward reaction exothermic or endothermic? Give an explanation for your choice..................................................................................................................................... (2)(iv) W hat other piece of information given in the equation supports your answer to (iii)?NO 2 + NO 2 → O 2N–NO 2 (1)[Total: 12]0620/33/M/J/13© UCLES 2013[Turn overForExaminer’sUse6S ulfuric acid and malonic acid are both dibasic acids. One mole of a dibasic acid can form two moles of hydrogen ions.H 2SO 4 → 2H + + SO 42–D ibasic acids can form salts of the type Na 2X and CaX.(a) M alonic acid is a white crystalline solid which is soluble in water. It melts at 135 °C.T he structural formula of malonic acid is given below. It forms salts called malonates.CH 2(COOH)2 or HOOC – CH 2 – COOH(i) H ow could you determine if a sample of malonic acid is pure?technique used .......................................................................................................... result if pure (2)(ii) W hat is the molecular formula of malonic acid? (1)(iii) W hen malonic acid is heated there are two products, carbon dioxide and a simplercarboxylic acid. Deduce the name and molecular formula of this acid..................................................................................................................................... .............................................................................................................................. [2] (iv) M alonic acid reacts with ethanol to form a colourless liquid which has a ‘fruity’ smell.I ts structural formula is given below.CC OOO OCH2CH 2CH 3CH 2CH 3W hat type of compound contains the group which is circled? (1)0620/33/M/J/13© UCLES 2013For Examiner’sUse(b) (i) S uggest why a solution of malonic acid, concentration 0.2 mol / dm 3, has a higher pHthan one of sulfuric acid of the same concentration. (1)(ii) D escribe a test, other than measuring pH, which can be carried out on both acidsolutions to con ﬁ rm the explanation given in (b)(i) for the different pH values of the two acids..................................................................................................................................... (2)(c) C omplete the following equations for reactions of these two acids.(i) sodium hydroxide + malonic acid → .................... + ....................[1].................... (ii) CuO + H 2SO 4 → .................... + .................... [2] (iii) Mg + CH 2(COOH)2 → .................... + ....................[2](iv) K 2CO 3 + H 2SO 4 → .................... + .................... + ....................[2][Total: 16]7 A lkanes and alkenes are both series of hydrocarbons.(a) (i) E xplain the term hydrocarbon ..................................................................................................................................... (1)(ii) W hat is the difference between these two series of hydrocarbons?.................................................................................................................................... (2)(b) A lkenes and simpler alkanes are made from long-chain alkanes by cracking.C omplete the following equation for the cracking of the alkane C 20H 42.C 20H 42 → 2C 4H 8 + 2C 2H 4 + ...............[1]0620/33/M/J/13© UCLES 2013[Turn overForExaminer’sUse(c) Alkenes such as butene and ethene are more reactive than alkanes.A lkenes are used in the petrochemical industry to make a range of products, which includes polymers and alcohols.(i) D ibromoethane is used as a pesticide. Complete the equation for its preparationfrom ethene.C C + Br 2 →HHH H[1](ii) T he structural formula of a poly(alkene) is given below.nC CH 3C CH 3HHD educe the structural formula of its monomer.[2](iii) H ow is butanol made from butene, CH 3 – CH 2 – CH = CH 2? Include an equation in your answer..................................................................................................................................... (2)(iv)C racking changes alkanes into alkenes. How could an alkene be converted into analkane? Include an equation in your answer..................................................................................................................................... (2)0620/33/M/J/13© UCLES 2013ForExaminer’sUse(d) 20 cm 3 of a hydrocarbon was burnt in 175 cm 3 of oxygen. After cooling, the volume ofthe remaining gases was 125 cm 3. The addition of aqueous sodium hydroxide removed carbon dioxide leaving 25 cm 3 of unreacted oxygen.(i) v olume of oxygen used = .......... cm 3 [1] (ii) v olume of carbon dioxide formed = .......... cm 3 [1](iii) D educe the formula of the hydrocarbon and the balanced equation for the reaction..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... (2)[Total: 15]11BLANK PAGEPMT12Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the publisher will be pleased to make amends at the earliest possible opportunity.University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.G ro u p140C eC e r i u m 58141P rP r a s e o d y m i u m 59144N d N e o d y m i u m 60P mP r o m e t h i u m61150S mS a m a r i u m62152E uE u r o p i u m63157G dG a d o l i n i u m64159T bT e r b i u m65162D yD y s p r o s i u m66165H oH o l m i u m67167E rE r b i u m68169T mT h u l i u m69173Y bY t t e r b i u m70175L uL u t e t i u m71232T hT h o r i u m 90P aP r o t a c t i n i u m 91238UU r a n i u m92N pN e p t u n i u m93P uP l u t o n i u m94A mA m e r i c i u m95C mC u r i u m96B kB e r k e l i u m97C fC a l i f o r n i u m98E sE i n s t e i n i u m99F mF e r m i u m100M dM e n d e l e v i u m101N oN o b e l i u m102L rL a w r e n c i u m1031HH y d r o g e n17L iL i t h i u m 323N aS o d i u m 1124M gM a g n e s i u m1240C aC a l c i u m 2045S c S c a n d i u m 2148T i T i t a n i u m2251V V a n a d i u m 2352C r C h r o m i u m 2455M n M a n g a n e s e 2556F e I r o n 2659C o C o b a l t 2759N i N i c k e l 2864C u C o p p e r 2965Z nZ i n c3070G aG a l l i u m3127A lA l u m i n i u m1311B B o r o n 512C C a r b o n614NN i t r o g e n716OO x y g e n819FF l u o r i n e928S iS i l i c o n1431PP h o s p h o r u s1532SS u l f u r1635.5C lC h l o r i n e1740A rA r g o n1820N eN e o n104H eH e l i u m273G eG e r m a n i u m3275A sA r s e n i c3379S eS e l e n i u m3480B rB r o m i n e3584K rK r y p t o n3639KP o t a s s i u m 1988S rS t r o n t i u m 3889Y Y t t r i u m 3991Z r Z i r c o n i u m4093N b N i o b i u m 4196M o M o l y b d e n u m 42T c T e c h n e t i u m 43101R u R u t h e n i u m 44103R h R h o d i u m 45106P d P a l l a d i u m 46108A gS i l v e r47112C dC a d m i u m48115I nI n d i u m49119S nT i n50122S bA n t i m o n y51128T eT e l l u r i u m52127II o d i n e53131X eX e n o n54137B aB a r i u m 56139L a L a n t h a n u m 57*178H fH a f n i u m72181T a T a n t a l u m 73184W T u n g s t e n 74186R e R h e n i u m 75190O s O s m i u m 76192I rI r i d i u m 77195P t P l a t i n u m78197A uG o l d79201H gM e r c u r y80204T lT h a l l i u m81207P bL e a d82209B iB i s m u t h83P oP o l o n i u m84A tA s t a t i n e85R nR a d o n86F rF r a n c i u m 87227A cA c t i n i u m899B eB e r y l l i u m4II I I I II V V V I V I I 085R bR u b i d i u m 37133C sC a e s i u m 55226R a R a d i u m 88T h e v o l u m e o f o n e m o l e o f a n y g a s i s 24d m 3a t r o o m t e m p e r a t u r e a n d p r e s s u r e (r .t .p .).a Xb a = r e l a t i v e a t o m ic m a s sX = a t o m i c s y m b o lb = p r o t o n (a t o m ic ) n u m b e rK e y *58-71 L a n t h a n o i d s e r i e s 90-103 A c t i n o i d s e r i e s D A T A S H E E T T h e P e r i o d i c T a b l e o f t h e E l e m e n t sPMT。

2013年全国大学生英语竞赛C类真题及答案

2013 National English Contest for College Students(Level C - Preliminary)(总分：150分答题时间：120分钟)Part I Listening Comprehension (30 marks)Section A (5 marks)In this section, you will hear five short conversations. Each conversation will be read only once. At the end of each conversation, there will be a twenty-second pause. During the pause, read the question and the three choices marked A, B and C, and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through the center.1.Why didn’t the man go to see Macbeth last week?A.He didn’t manage to get a ticket.B.He had to attend a conference.C.He had a better production to watch.2.What does “Fill Me In” refer to in this conversation?A. A type of upgraded mobile phone.B. A well-selling magazine.C. A writer’s new book series.3.Why doesn’t the woman like the bag?A.She doesn’t like the pattern.B.It’s not easy to carry.C.It’s too big for her.4.What makes a bad CV according to the man?A.Fake information.B. Terrible writing.C. Undesirable length.5.How will Cathy continue her Spanish learning?A.She’s going to make a friend in Spain.B.She’ll communicate with a Spanish friend in Spain.C.She’ll practice speaking Spanish with an English friend.Section B (10 marks)In this section, you will hear two long conversation. Each conversation will be read only once. At the end of each conversation, there will be a one-minute pause. During the pause, read the question and the three choices marked A, B and C, and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through the center.Conversation One6.What traffic accident are the speakers talking about?A. A kid was knocked down by a car.B.Two cars crashed into a shop.C. A car ran into a wrong place.7.Why did the accident happen according the woman?A.There were many shops around.B.The crossing is in a wrong place.C.There was no crossing here.8.Which of the following is the suggestion they made?A.More traffic lights should be installed.B. A speed camera should be mounted.C.More policemen should patrol that area.9.Where, as the woman mentioned, has got improved traffic?A.Her own neighborhood.B.Her big brother’s neighborhood.C.Her parents’ neighborhood.10.How was the man punished for his traffic offence?A.He was fined 100 pounds with extra penalty points.B.He had to pay 150 pounds and got 6 penalty points.C.He finally paid 600 pounds without any penalty points.Conversation Two11.Why is the expert opposed to the view that memory aids make your memory worse?A.There is no evidence showing that memory aids are invalid.B.Human beings’ brain functions mainly through memory aids in an effective way.C.Memory aids encourage an organized approach which helps the brain functioneffectively.12.What is interview’s attitude towards the idea that visual image help the memoryA.It is hard to believe.B.It is nothing strange.C.It is obviously nonsense.13.Who developed the system of memory aids centuries ago?A.Inhabitants on an isolated island.B.The Ancient Greeks.C. A great psychologists.14.How does mapping out notes affect the brain?A.It is helpful in reflecting the way people link information in the brain.B.It prevents people from arranging things logically.C.It makes people’s brain function t he opposite way.15.What tends to affect people’s ability to think clearly?A.Upbringing and innate differences.B.Worry and anxiety.C.Their aptitudes.Section C (5 marks)In this section, you will hear five short news items. After each item, which will be read only once, there will be a pause. During the pause, read the question and the three choices marked A, B andC, and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through the center.16.How can social media influence the presidential election in the USA according to thelatest research?A.It can help voters to choose their president.B.It can help to ensure the fairness of the elections.C.It can help to increase the number of voters.17.What honorary title has Yaya Toure been granted?A.The African Player of the Year.B.212 Star of the Confederation of African Football.C.The Ivory Coast star.18.Why did Reshma Saujani set up the organization “Girls Who Code”?A.To raise women’s status in the field of science.B.To improve girls’ aptitude and performance in STEM.C.To arouse girls’ interest in science and technology.19.Which tablet computer’s hardware inside is more powerful?A.The CNET Kum.B. The Google Nexus 7.C. The Apple iPad mini.20.What does the company announce that it can do for the United States?A.It can reduce the amount of plastic waste.B.It can help to recycle the plastic waste.C.It can increase the amount of exports.Section D (10 marks)In this section, you will hear a short passage. There are 10 missing words or phrases. Fill in the blanks with the exact words or phrases you hear. The passage will be read twice. Remember to write the answers on the answer sheet.If you (21) ____ smooth skin that glows with youth, the chances are that at some point you will have heard the exhortation to drink lots of water in order to (22) ____ those evil toxins and keep your skin healthy.The exact amount people suggest varies. US – based advice (23) ____ eight glasses a day, while in hotter climates people are advised to drink to more to (24) ____ higher rates of sweating. But regardless of the exact volume of water suggested, the principle behind the advice remains the same --- taking extra water on board will keep your skin hydrated. In other words, water acts like a moisturizer, but from the inside out.This is such a common idea you might be surprised at the (25) ____ to back up. You might expect there to be countless studies where people are (26) ____ two groups, one assigned to sip water all day, the other to drink a normal amount. Then the smoothness of the skin could be (27) ____ a month or so later to establish whether sipping more lead to smoother skin.In fact such studies are rare, partly because water can’t be patented, so it is hard to find anyone to fund such research when there will be no new (28) ____ or cosmetic to sell that could repay the costs. A review by the dermatologist Ronni Wolf at the Kaplan Medical Center in Israel found just one study looking at the effect of long-term water intake on the skin. But the resultswere (29) ____. After four weeks, the group who drank mineral water showed a decrease in skin density, which some believe suggests the skin is retaining more moisture, while those who drank tap water showed an increase in skin density. But regardless of the type of water they drank, it made no difference to their (30) ____ or to the smoothness of their skin.Part II Vocabulary and Structure (15 marks)There are 15 incomplete sentences in this section. For each blank there are four choices marked A, B, C and D. Choose the one that best completes the sentence. Then mark the corresponding letter on the answer sheet with a single line through the center.31. The new star said to the journalists that she _C___ the opportunity to show that she could playa serious film role.A. greetedB. rejoicedC. welcomedD. cheered32. We haven’t really __D__ a solution to the problem yet, which makes the boss really frustrated.A. built upB. fallen back onC. brought overD. come up with33. Personally, I am __C__ banning cigarette smoking completely, especially in public areas.A. in touch withB. apart fromC. in favor ofD. regardless of34. Until a firm agreement has been reached, I am not __C__ to accepting the offer.A. accustomedB. dedicatedC. committedD. entitled35. The government is making every effort to __B__ an economic crisis, but it seems nothing could help.A. eliminateB. avertC. impedeD. swerve36. __B__ a serious crime, what exactly should you do?A. Unless you witnessB. If you were to witnessC. If only you witnessD. since you witness37. During examinations candidates are always supposed to stay in seats, keep their eyes on the work, _A___ to anyone.A. and not speakB. but could not speakC. rather than speakD. instead of speaking38. Realizing that he hadn’t got enough money and _D___ to borrow any from his parents, he decided to sell his house.A. wanted notB. not to wantC. wanting notD. not wanting39. There’s no point waiting here any longer. We _C___ go and have something to eat.A. can hardlyB. are bound toC. might as wellD. will have to40. While many people may refer to up-to-minute news, it is unlikely that television and the Internet _A___ the newspapers completely.A. will replaceB. replaceC. are replacingD. have replaced41. She married a very nice young architect from Belfast, _A___ she met on a bus during her journey to Northern Ireland.A. whoB. whenC. whichD. where42. It is a kind of illness that can result in total blindness if __D__A. to leave untreatedB. is left untreatedC. leaving untreatedD. left untreated43. ----I’m so disappointed with my son! He just wouldn’t practice the piano!----Take it easy. You can lead ___B_ to water, but you can’t make it drink.A. a duckB. a horseC. a cowD. a dog44. ----Good morning, Madam! I’d like some information about the course.----Certainly. _B___A.I’m afraid I don’t know more than you either.B.Is there anything I can do for you?C.What exactly would you like to know?D.How much information did you know?45. ---- How do you feel about countries that don’t try to reduce global warming?---- __A__, those countries care more about money than saving the planet.A.As far as I’m concernedB. It’s none of ou r businessC. We’re not to blameD. Things are under controlPart III Cloze (10 marks)Read the following passage and fill in each blank with one word. Choose the correct word in one of the following three ways: according to the context, by using the correct form of the given word, or by using the given letters of the word. Remember to write the answers on the answer sheet.According to recent surveys, 72% of all Americans believe that the United States government is (46) hiding____ information about UFOs. Almost 68% of people think that the government has secret knowledge of extraterrestrial life. It is not (47) _surprising__ (surprise) that the government has come under more and more (48) pressure____ to declassify its UFO records and make them public. A variety of different groups have been involved in these efforts.One group to become involved is called CFI, the Coalition for Freedom of Information, John Podesta, who was White House Chief of Staff during Bill Clinton’s (49)presidency____(president), is one of the many high-powered people active in this group. CFI’s aim is not to prove the (50) _existence___(exist) of extraterrestrial life, but to make it easier for scientists in general to study unexplained aerial phenomena. Podesta and his group has asked the Pentagon to declassify its UFO records and therefore provide scientists (51) with____ data that will help in the study of UFOs.CFI has requested the release of information on several UFO cases, starting with the Kecksburg, Pennsylvania, incident. This incident took (52) __place__ in 1965 when a large acorn-shaped object, the size of a small car, crashed in Pennsylvania. Some analysts say it could have been the spacecraft Kosmos 96 that had been launched towards Venus by the Soviet Union, but failed to escape Earth’s (53) gravity____. Others say the object did not look anything like spacecraft built on Earth in 1965.(54) Additionally___, the people of Kecksburg want to know what happened. On that (55) afternoon____, hundreds of eyewitnesses watched a fiery streak of light descend from the sky towards Earth. Officials explained that nothing was found or recovered and that maybe the fireball in the sky was a meteor. But many witnesses say they saw a number of military personnel from the Army and the Air Force search the woods, and later that evening, saw a large militarytractor-trailer coming from the area carrying a large object under a tarp.Part IV Reading Comprehension (40 marks)Read the following passage. Each passage is followed by several questions. Respond to the questions using information from the passage. Remember to write the answers on the answer sheet.Section A (10 marks)Questions 56-60 are based on the following passage.The average automatic teller machine (ATM) is not very smart. It will give money to anyone who has the right card and punches four or five keys in the right order. Some analysts estimate that as many as 30% of ATM transaction worldwide are cases of theft. To increase security at cash machines, some banks have tried to make their ATMs a little smarter. A small camera on the machine looks directly into the eye of every customer. It scans one iris and compares the tiny patterns of ridges, dots, and other features to a code in its computer. If there is a match, the ATM will start counting out cash. If not, a message is automatically sent to the nearest police station.Iris-scanning is one fast-growing form of biometric identification --- determining who someone is by examining features the body. One of the earliest biometric techniques was fingerprinting. The line on fingerprints are unique to each person, so not even identical twins have the same fingerprints. Fingerprinting has become famous as a way of finding out who committed a crime, but it very often fails. A careful criminal can swear gloves, avoid touching thing, or even alter his fingerprints by burning, cutting, or scraping them. In the search for a more reliable system, security experts have focused on the eye.Like a fingerprint, every iris is, for all practical purposes, unique. Each person’s right iris is even different from his or her left one. A low-cost digital camera, like the kind installed at ATM machines, can easily detect hundreds of different features in the iris. The chance of two irises having the same features is close to zero. Tests have shown that iris-scanners are very hard to fool. They can tell the difference between a real iris and a false one. They can see right through colored contact lenses, eyeglasses, and even mirrored sunglasses. Although many criminal are willing to burn or cut their fingers in pursuit of the perfect crime, few would be willing or able to alter their irises.T o make iris-scanning work, a computerized database has to match certain iris features with certain people. This means that each A TM customer has to allow a bank to photograph his or her iris and keep that highly personal information in a computer. Some people have worried, however, that an increased use of iris-scanning will lead to a dangerous loss of privacy. By mountingiris-scan cameras in public places, governments could track a private citizen all day long without the person’s knowledge. This would be a great advantage to the police, but it could also give corrupt officials a new way to control their opponents. The military’s development of tiny robots suggests that government iris-scanners could even invade private homes!Questions 56-60Complete the summary with words from the passage, changing the form where necessary, with only one word for each blank.Section B (10 marks)Questions 61-65 are based on the following passage.Seed catalogues feature hundreds of flowering species. For the persons just beginning garden this can be bewildering, and below are the details of some popular choices, nearly all of which should be sown in the spring. With the exception of busy lizzies, which need a little care, they are all very easy to grow from seed.DahliasThese are sturdy plants bearing showy flowers in a wide range of rather gaudy colors. Sow in a frame in April and plant the seedlings out when frosts are over. Dahlias flower throughout the summer and into the autumn. When autumn frosts begin to make them look unhappy, you should dig up the tuberous roots and save them. A frost -free loft, shed or garage is the ideal place. The following spring you plant the tubers instead of sowing seed again.LupinsLupins are hardy perennials. This means that the plants will stay in your garden and carry on flowering year after year. Seed sown in April will usually give you some spikes of colors in the first summer, and year by year the plants get bigger and the flowering stems get taller and grander. Selective breeding has led to the introduction of some fine, bicolored varieties in some dazzling shades. The short -lived flowers make a real misunderstanding spectacle.Busy lizziesLike dahlias, busy lizzies need to be started offunder glass, as they cannot stand frost, and pantingout is best done in May. Outdoor flowering ends inSeptember, so beat the frosts and bring your favoritespecimens indoors to give your home some sintercolor! Indoors they will carry on floweringindefinitely, though you may like to plant them outagain when spring returns. Like pansies (below) they do very well in sun or shade, but the soil must be moist. Most varieties grow to be a height of only 20 cm or so.PotentillasPotentillas are hardy shrubs. In other words, the woody branches spring from groundlevel—there is no central trunk. Seed is probably best sown in autumn, in which case you should keep the plants in a sheltered spot until April offers favorable conditions for planting out. Once flowering begins in early summer the best varieties (such as Melton Fire) will stay in bloomATM transactions are often cases of theft, where an unauthorized user takes (56) __money_. To decrease insecurity, some banks have installed iris -scanning machines at ATMs. These small cameras scan the user’s iris, recording its features and (57) _comping___ them to a digital file. Every person has a (58) _ unique ___ iris, making iris identification highly reliable. Earlier efforts at biometric identification often relied on fingerprints. However, fingerprints can easily be (59) altered____ through cutting, burning or scrapping. Iris scanners are so effective that they can even see through contact lenses and mirrored sunglasses. Use of iris scanners would provide great advantages to the police. However, others worry about a loss of (60) ____.almost ceaselessly for years on end while at the same time spreading out to provide ground cover or a low hedge.PansiesPansies have a good long flowering season year after year, and some varieties can be sown in spring to give truly splendid results the first autumn. Unlike dahlias and lupins, which can easily grow a meter tall, pansies grow no higher than 10 or 20 cm. Their soil, position and moisture requirements are just like those of busy lizzies but pansies differ in being hardy. Give them a try!Questions 61-63Decide whether the following statements are true (T) or false (F) according to the passage.61. Both dahlias and lupins, which are sown in April, need protecting from frost.62. Brought indoors in autumn, dahlias, busy lizzies and potentillas will carry on flowering almost non-stop.63. Among all the flowers busy lizzies are not very easy to grow from seed.Section C (10 marks)Questions 66-70 are based on the following passage.When looking for love, people may go to some extreme lengths. They might go on blind dates set up by family and friends. They might write personal ads to place in newspapers. Or they might use a computer to help them in their search for a soul mate by joining an online dating services. Some people have even tried to find their perfect match through game shows on television. Many of these TV dating shows, including The Bachelor and Who Wants to Marry a Millionaire? have proved to be ratings blockbusters, with millions of viewers watching each week to find out which of the contestants will find true love.Of all these game shows, perhaps the one with the most unexpected ending was Mr. Right, which was shown in England in 2002. On the show, a bachelor, thirty-five-year-old Lance Gerrard-Wright, dated fifteen women to find the one who was his ideal partner. The host of the show was Ulrika Johnson, an English celerity originally from Sweden. For seven weeks on the show, Gerrard-Wright took turns going on dates with each of the women, taking them to expensive restaurants and exotic locations. He even met the women’s families and introduced them to his own. Then at the end of each episode, he would choose between one and three of the contestants with whom he had felt the least compatible, and say goodbye to them.At one point during the series, one contestant volunteered to leave because she said she didn’t find him attractive. After two dates she said she had had enough, and she couldn’t see it working. “He wasn’t my cup of tea.” In another episode the woman he was on a date with burst into tears when he called her by another contestant’s name. “You called me by another girl’s name. I can’t believe you did that. I really liked you,” she sobbed.But in the final episode, the woman he eventually chose decided she didn’t want to marry him after all. “I think you’ve chosen me because you have to choose someone,” she said. Maybe this was because she already knew he had fallen in love---with the show’s host!After leaving the show, Gerrard-Wright and Johnson were seen dining together and attending parties around London more and more often. Finally, on May 1, 2003, Gerrard-Wright proposed to Johnson on the steps of St. Paul’s Cathedral. And she accepted his proposal right away, although it was a conditional acceptance. Johnson has two children from previous relationships—aneight-year-old son, Cameron, and a two-year-old daughter, Bo. She had to make sure that they agreed to the marriage. Luckily, they did. Gerrard-Wright said, “In the end the show did work for me. I grabbed an opportunity to get a girlfriend and I did. Ulrika’s gorgeous.”Questions 66-68Complete the following sentences with information given in the passage in a maximum of 2 words for each blank.66. Lance Gerrard-Wright went to ____ to go on the show Mr. Right in order to find his perfect match.67. On the show, Lance had the opportunity to date many gorgeous women among whom there might be one that he was almost ____.68. Ulrika accepted Lance’s proposal ____ that her children agreed to their marriage as well. Questions 69-70Choose the best answer according to the passage.69. Which of the following did NOT happen on the show?A. Lance went on dates with several women.B. The candidates went to some very good restaurants.C. Ulrika consulted her parents before she made her decision.D. The women met Lance’s family.70. What happened after seven weeks of doing the show?A. All of the women found their beloved.B. Lance started to date with the show’s host.C. One of the women on the show couldn’t help crying.D. Ulrika asked Lance to marry her.Section D (10 marks)Questions 71-75 are based on the following passage.Alaska is disappearing slowly but surely. Since the 1950s, it is estimated that as much as 15 percent of Alaska’s area has disappeared. But how can a whole state be disappearing?One reason for Alaska’s gradual disappearance is the melting its glaciers. According to one geologist at the US Geological Survey, about 98 percent of Alaska’s glaciers are either unmoving or diminishing. This diminishing seems mainly due to the increase in global temperatures. Since the 1960s, the average year-round temperature has increased by 5℉. Furthermore, the average winter temperature has increased by 8℉. Presently, an estimated 24 cubic miles of ice is disappearing from Alaskan glaciers every year. It may be even more in the near future, as some scientists predict that the average world temperature could go up 2.5 to 10℉by the year 2010.Another problem contributing to Alaska’s gradual disappearance is its permafrost. (74) Much of the land in Alaska was permanently frozen, or frozen for most of the year, thus maintaining its integrity. Now, the thawing permafrost is causing a number of problems on land. Roads and utility poles are collapsing. Also, the hard permafrost which originally prevented beaches from eroding during violent storms is now melting. Affected villages are forced to relocate. For villages on small low islands, one terrible storm could wipe out the entire community.The melting permafrost and increasing temperature are also having a negative impact on the forests of Alaska. As the permafrost under the forests melts, insects that normally don’t turn upuntil the warmer seasons are appearing sooner. The spruce-bark beetle, for example, is increasing in numbers as a result of global warming. It usually takes about two years for these beetles to grow and reproduce in a very cold weather. However, due to the increase in temperatures, spruce-bark beetles are damaging as many trees in one year as they previously damaged in two. At this rate, Alaska’s forest won’t survive the turn of the century.Some scientists believe that human activity is linked to a global increase in weather temperature. Whether the rising temperature are caused by human activity or natural changes, the fact remains that Alaska is warming. Some others argue that global warming may be a normal trend on the Earth’s temperature chart. (75) One theory argues that we are near the end of aso-called “Little Ice Age”, and the return of the glaciers is natural result of this cycle. Whether natural or produced by humans, there is little hope for the immediate future of glaciers as we know them. Horribly, this could be a preview of what will happen to the rest of the world in the next century.Questions 71-73Answer the following questions briefly according to the passage.71. What are disappearing in Alaska actually?72. How much ice is melting each year according to the survey?73. Why do insects damage more trees than before?Questions 74-75Translate the underlined sentences in the passage into Chinese.74. Much of the land in Alaska was permanently frozen, or frozen for most of the year, thus maintaining its integrity75. One theory argues that we are near the end of a so-called “Little Ice Age”, and the return of the glaciers is natural result of this cycle. Whether natural or produced by humans, there is little hope for the immediate future of glaciers as we know them.Part V Translation (10 marks)Translate the following sentences into English, using the hints given in brackets. Remember to write the answers on the answer sheet.76. 宴会时间就要到了，但她仍纠结于是否应该去。

2013年GCT数学真题解析

| PF2 |2 + | PF1 |2 −52 1 = , 2 | PF2 || PF1 | 2
| PF2 |2 + | PF1 |2 −2 | PF2 || PF1 | | PF2 |2 + | PF1 |2 −52 = | PF2 || PF1 | 又 4 = (|PF2 | − | PF1 |)2 =
2= a, AD 2= a, AE 2 2= a, AF 4a S =
) cm 2 B．20 C．18 D．16
1 2 (a + 2a 2 + 4a 2 + 8a 2 ) = 30 解 2
得 a = 2 ，所以 = FB 10, = AD 4 ， S阴 =0.5 × 4 × 10=20 7．某个锐角的正弦和余弦是二次方程 ax 2 + bx + c = 0 的不同的两个根，则 a, b, c 之间的关系是( )
D． f (2) < f ( 3) < f (3)
− f ( x + 1) = f ( x) ，所以 f ( x) 的周期为【解析】由于 f ( x +1) = − f ( x) ，令 x= x + 1 ，则 f ( x +2) =
2 ，有 f (3) = f (−1), f (2) = f (0), f ( 3) = f ( 3 − 2) ， f ( x) 在区间 [−1, 0] 上严格单调增则 f (−1) < f ( 3 − 2) < f (0) ，即 f (3) < f ( 3) < f (2) PS：本题还可以证明 f ( x) 在区间 [0, 1] 上严格单调递减的。 10． i 为虚数单位， z = A．0 【答案】A 【解析】由于 i 2 = −1 ， z=

2013 全国大学生英语竞赛B类真题答案

2013 National English Contestfor College Students(Level B - Preliminary)参考答案及评分标准Part I. Listening Comprehension（30 points）1—5CBCBA 6—10 AABBC 11—15 BACAB 16—20 BABAC21. a dictation 22. keep pace. 23. An active listener 24. the topic 25. heading26. paraphrasing 27. summarising 28. rewrite 29. thoughts and comments 30. useful study aid Part II援Multiple Choice (15 points)Section A (10 points)31—35 ACBBC 36—40 DACBASection B (5 points)41—45 ABCBDPart III援Cloze (10 points)46. popular 47. adopted 48. available 49. longer 50. nervous51. space 52. sufficiently 53. but 54. affectionate 55. retiredPart IV. Reading Comprehension (40 points)Section A (10 points)56. D 57. C58. ordering a hamburger 59. ignorant and inexperienced 60. primary source materialsSection B (10 points)61. For sport or because it蒺s part of a traditional culture.62. Stuff and mount the dead animals.63. Overpopulation of certain species.64. Outbreaks of fowl cholera.65. They kill a limited number of bowheads a year.Section C (10 points)66. a smaller firm 67. promotion prospects 68. morale69. his/her life miserable 70. got on withSection D (10 points)71. N 72. Y 73. Y74. 在我们的竞争对手感到拮据的时候出现这种情况，让人感到非常振奋。

2013中国女子数学奥林匹克试题及其解答

2013中国女子数学奥林匹克试题及其解答1.证明（张云华）1.证明（mavropnevma ）Let , . The region is the triangle ,and , thus the triangles of largest possible area are and . But(equality for is for ,disallowed).(equality foris for ).EDIT. Referring to the next post - it is interesting to figure out the envelope of the linesis the parabola , but in some way it is irrelevant, since the problemfunctions for a fixed , with fixed on the parabola for some , and thetriangular area being delimited by the tangent to that parabola at .1.证明（kunny）, thus theparabola is envelope of the linesWhich touches at .The domain of the family of the lines swept by is shown by the shaded region, excluded twopoints .Edit:I was misreading the context problem, thank you for pointing put it, mavropnevma.I have just attached another figure.Needless to say, mavropnevma's solution is perfect.P.S.I remember that the similar problem original problem has been posed in 1970's in Tokyo University entrance exam/Science.According to my memory, let be the maximum area of any triangle which is involved in theregion in original problem, then draw the graph of to find the extrema of .Here is the similar problem posed in Tokyo University entrance exam/Science, second round, 1978In the -plane, let be the part which is correspond to of the parabola ,that is to say, .Let the tangent Line of at intersects with the line at and intersects withthe line at .Let . We are to consider the questions as below in the range of.(1) Let denote the area of triangles by , respectively. Find the rangeof such that .(2) Let be the domain enclosed by line segments and .Note : contains line segments and .Let be the maximum area of the triangle with a vertex which is contained in .Find the function and draw the graph, then find the exterme value.Note : A function has local minimum (or local maximum) at a point, which means for all points which is closed to ,holds. We call local maximum, local minimum as extreme value.2.证明(Luis González)Let and Let be the incircleof touching at Clearly and are homothethic with incirclesbut since are symmetric about the midpoint of (isthe M-excircle of MAB), it follows that and are homotheticwith corresponding cevians2.证明(Andrew64)As shown in the figure below.is the intersection of and .Therefore , , meet at the same point .Attachments:link17.jpg [ 37.23 KiB | Viewed 52 times ]3.证明(mavropnevma)Since it is irrelevant which persons of the same gender know each other, we may assume there ore none such, and consider the bipartite graph having the left shore made ofthe boys and the right shore made of the girls, with an edge connecting a boy and a girl ifthey know each other. The condition means does not contain any induced cycle of length ,and the requirement is to show the number of edges satisfies .Thus it is an extremal graph theory question, for bipartite graphs with forbidden 's; bysymmetry we should also have .Denote by the set of girls that each knows exactly one boy, and by the set of girls that eachknows more than one boy; take and . We obviously have and.Let us count the number of objects , where is a girl, are distinctboys, and knows both . For each of the doubletons there is at mostone girl knowing them both (by the condition), so . Moreover, by pigeonholewe have .On the other hand, we have, by Jensen's inequality.We thus need , so.Finally, we get .For equality to be reached we obviously need , namely for each pair of boys having exactly one girl knowing both of them; and then we need .3.证明(crazyfehmy)Another solution: Consider the bipartite graph where there are girls andboys and denote the girls by 's and boys by 's as vertices.Let denote the number of edges from the vertex to set . If is connected to some andthen for any the girl must not connected to both and . Now let us count suchpairs. For every girl there are many pair of edges. Since all such edge pairs must bedistinct for all girls, and since there are at most such pairs, we haveor equivalentlyNow assume that are greater than or equal to and areor . Then we haveand we need to show that .Since for we have and hence .Now by Cauchy-Schwarz inequality we haveand if , we haveand we need to show that . Assume . Then we havewhich means that which is a contradiction. So, we are done.4.解（crazyfehmy）Let be called a nice pair if satisfies the conditionsstated in the problem.Firstly, we shall prove a lemma:If is a nice pair then for all integers and .Proof: Let or and divides for some integers and. Then we can find another pair such that and. (The proof is easy) Then consider the systemand . By the Chinese Remainder Theorem this system has a solution and such that both and isan element of which means that is not a nice pair becauseis divisible by .Now, we shall show that if or then has asolution for all integers . For the proof assume there exists an integer such thathas no solution in integers. Then it is easy to see thathas also no solution for all integers which are not divisibleby . Now take and consider the numbers . For all of these numbers,we have no solution and there are such numbers. Since all square residues have solutions(take ) and there are square residues modulo including zero, this means that forall nonsquare residues , the equation must have no solution. However, for the numberis not a square residue but so for we have asolution which is a contradiction. For the number is not a square residue buthas a solution since is a square residue. Hence we again obtain a contradiction so the second lemma is also proved.Now, since can take every value modulo and we must have andand also we must have and if is a nice pair. So, can take only three values. We will consider each case separately:If then we must have which meansIf then we must have whichmeansIf then we must have whichmeansIf we count these possibilities, if i am not wrong, we get.4.解（dinoboy）First, remark that it suffices for to be injective modulo and .For modulo simply note that we require .For modulo or we require for some thatNow, what values can take modulo ? It is a simple exercise to show allvalues modulo can be obtained (just express it as and then aswe can transform the problem to what values modulo can beexpressed as , which is known to be all of them). Therefore the only way this problemsworks out is if and .Therefore we simply require that and . For each value of there are valuesof modulo , 10 modulo and modulo so the answer should simply be.Note: To show takes all values modulo without relying onis not hard, but I'm lazy and felt like reducing it to an already solved problem.4.解（yunxiu），so ，hence satisfies the problem.So the answer should be .6.解（crazyfehmy）If let then satisfiessince is equivalent to whichhas always a solution in the set for all and since is odd.Now we will show that if then the condition does not satisfy. Let be theelements of the set . Consider the sums and let. Since 's are different modulo , the numbers 'sare also different modulo . On the other hand, none of 's can be equivalent to modulobecause otherwise we would have two equivalent terms. Hence is apermutation of and by adding up these equations we getwhich means. Now do the same procedure for all's to get. Let and. Then we have . So, we havemany numbers equivalent to each other modulo . However, we know that there are manynumbers modulo which are all equivalent to each other modulo . Hence in order for 's tobe different modulo, we must have which means that and hence. Soand we are done.Hence all possible values are .7.证明（Luis González ） Let cut again at Since is the exsimilicenter ofthen is midpoint of the arc ofbisects externally is midpoint of the arc ofis external bisector of andNote that is a Thebault circle of the cevian of externally tangent to itscircumcircle By Sawayama's lemma passes through its C-excenter isC-excenter ofis M-isosceles, i.e. Hence iscircumcenter of7.证明（Andrew64）As shown in the figure. Let be the intersection of and .It's fairly obviousSo we have, andare concyclic.So , andThus, Consequently .Namely is the bisector of.Attachments:link18.jpg [ 31.39 KiB | Viewed 93 times ]8.证明（duanby）hint:(a-b)(c-b)(a-d)(c-d)in detail: product (a-b)(c-b)(a-d)(c-d) for everya,c be the number on , b,d be the number onfor point x,y if they are not ajjectent then in the product, it will occur twice, if it's ajjectent it's appears only once, and also chick the point that are on and then we get it.iampengcheng1130 2013中国女子数学奥林匹克第7题的解答。

2013滑铁卢竞赛试题答案

The CENTRE for EDUCATION in MATHEMATICS and COMPUTING cemc.uwaterloo.ca
2013 Euclid Contest
Wednesday, April 17, 2013
(in North America and South America)
since AC > 0. Finally, the perimeter of
3. (a) The parity of an integer is whether it is even or odd. Since the Fibonacci sequence begins 1, 1, 2, 3, 5, 8, 13, 21, . . ., then the parities of the ﬁrst eight terms are Odd, Odd, Even, Odd, Odd, Even, Odd, Odd. In the sequence, if x and y are consecutive terms, then the next term is x + y . In general, suppose that x and y are integers. If x is even and y is even, then x + y is even. If x is even and y is odd, then x + y is odd. If x is odd and y is even, then x + y is odd. If x is odd and y is odd, then x + y is even. Therefore, the parities of two consecutive terms x and y in the Fibonacci sequence determine the parity of the following term x + y . Also, once there are two consecutive terms whose parities match the parities of two earlier consecutive terms in the sequence, then the parities will repeat in a cycle. In particular, the parities of the fourth and ﬁfth terms (Odd, Odd) are the same as the parities of the ﬁrst and second terms (Odd, Odd). Therefore, the parities in the sequence repeat the cycle Odd, Odd, Even. This cycle has length 3. Therefore, the 99th term in the Fibonacci sequence ends one of these cycles, since 99 is a multiple of 3. In particular, the 99th term ends the 33rd cycle. Each cycle contains two odd terms. Therefore, the ﬁrst 99 terms in the sequence include 2 × 33 = 66 odd terms. Finally, the 100th term in the sequence begins a new cycle, so is odd. Therefore, the ﬁrst 100 terms include 66 + 1 = 67 odd terms. (b) Suppose that the ﬁrst term in the given sequence is a and the common diﬀerence is d. Then the ﬁrst four terms are a, a + d, a + 2d, a + 3d. From the given information, a + (a + 2d) = 6 and (a + d) + (a + 3d) = 20. The ﬁrst equation simpliﬁes to 2a + 2d = 6 or a + d = 3. The second equation simpliﬁes to 2a + 4d = 20 or a + 2d = 10. Therefore, (a + 2d) − (a + d) = 10 − 3 or d = 7. Since a + d = 3 and d = 7, then a = −4. Therefore, the tenth term in the sequence is a + 9d = −4 + 9(7) = 59. 4. (a) There are ﬁve odd digits: 1, 3, 5, 7, 9. We consider the positive integers less than 1000 in three sets: those with one digit, those with two digits, and those with three digits. There are 5 positive one-digit integers with one odd digit (namely 1, 3, 5, 7, 9). Consider the two-digit positive integers with only odd digits. Such an integer has the form XY where X and Y are digits. There are ﬁve possibilities for each of X and Y (since each must be odd). Therefore, there are 5 × 5 = 25 two-digit positive integers with only odd digits. Consider the three-digit positive integers with only odd digits. Such an integer has the form XY Z where X , Y and Z are digits.

2013年全国剑桥杯英语能力竞赛题初中B组

第 1 页共 8 页2013年全国“剑桥杯”英语能力竞赛(重庆赛区)初赛题初中B 组笔试题主办：外语教学与研究出版社剑桥大学出版社重庆片主办：重庆晨报四川外语学院英语学院重庆片承办：重庆晨文文化传播有限公司校园在线考试时间：60分钟总分：100分说明：全卷共五大题50小题，所有答案均填涂在机读卡上，否则将作零分处理，只交机读卡，试卷自己保管。

第一部分基础知识 (44分)I. 单项选择。

(每小题2分，共20分)根据语境，从四个选项中选择一个最佳的答案完成语境，并把机读卡上相应答案的番号涂黑。

1. Here's Mary's plan for one week during her summer vacation. What kind of plan is this? A. A trip plan. B. A party plan. C. An eating plan. D. An exercise plan.2. I put the fish in the ice box to keep it ______.A. freshB. fullC. newD. young3. The pants I bought last year are too small now. I think I need a new ______. A. belt B. pair C. shirt D. space4. How can you study in the living room when other people are watching TV? I think you need a _______ place.A. cleanerB. quieterC. saferD. smaller5. Marsha thought her friends would do something ______ to celebrate her birthday, but they just gave her a little card.A. correctB. honestC. quickD. special6. I cannot understand why Steven bought so many watches but never wears ______ of them. A. any B. both C. every D. others7. Elsa hates going shopping, _______ she went last night when her grandpa asked her to buy some medicine for him.A. becauseB. butC. ifD. so 8. Alex: Why are you still here? It's already eight o'clock.Tom: Because I ______ my work. Don't worry. It's almost done.A. wasn’t finishingB. wouldn’t finishC. haven’t finishedD. won’t finish9. Lucy: Does Aunt Tara enjoy __________?Mark: Yes. She has three dogs, two rabbits, four birds, and some fish in her house.A. collecting dollsB. keeping petsC. visiting the zooD. working on the farm10. 下列成语“熟能生巧”用英语正确的选项是__________。

VCE考试数学2013试题1

Question 7 (6 marks) The probability distribution of a discrete random variable, X, is given by the table below. x Pr(X = x) a. 0 0.2 1 0.6p2 2 0.1 3 1-p 4 0.1 3 marks
b.
On the axes above, sketch the graph of g(x) = | f (x)| + 1, for x [-2, 2]. Label the end points with their coordinates.
2 marks
Question 9 – continued
6
Question 6 (3 marks) Let g: R → R, g(x) = (a – x)2, where a is a real constant. 31 The average value of g on the interval [–1, 1] is . 12 Find all possible values of a.
-x
y = f (x) P (x, f (x))
O
Q
x
a.
Find the area, A, of the triangle OQP in terms of x.
1 mark
Question 10 – continued
13
2013 MATHMETH (CAS) EXAM 1
b.
Find the maximum area of triangle OQP and the value of x for which the maximum occurs.

2013年英语专业四级真题及答案详解(含阅读理解).docx

TEST FOR ENGLISH MAJORS (2013)—GRADE FOUR—TIME LIMIT: 130 MINPART 1 DICTATION 15 MINListen to the following passage. Altogether the passage will be read to you four times: During the first reading, which will be read at normal speed, listen and try to understand the meaning. For the second and third readings, the passage will be read sentence by sentence, or phrase by phrase, with intervals of 15 seconds. The last reading will be read at normal speed again and during this time you should check your work. You will then be given 2 minutes to check through your work once more.PART 2 LITENING COMPREHENSION 20 MINSECTION A CONVERSATIONSIn this section, you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.Questions 1 to 3 are based on the following conversation. At the end of the conversation you will be given 15 seconds to answer the questions.1.According to the conversation, an example of“Christmas trimmings”could beA. presents.B. fruitsC. sauceD. meat2.A Christmas lunch would include all the following EXCECTA. roast turkeyB. sweet potatoesC. meatD. carrots3.Why did Helen come to Rob?s house?A. She wanted to talk to Bob.B. She had come to help Bob.C. She had been invited to lunch.D. She was interested in cooking.Questions 4 to 7 are based on the following conversation. At the end of the conversation you will be given 20 seconds to answer the questions.4.Why did the woman phone the club?A. She wanted to know more about it.B. She was a new comer and felt lonely.C. She wanted to learn a new language.D. She was interested in social activities.5.We learn from the conversation that the clubA. mainly organize language activities.B. accepts members from local students.C. has been set up for a long time.D. is increasing its membership.6.According to the conversation, the woman might come to practice German onA. Wednesday.B. Tuesday.C. Monday.D. Friday.7.What is the man going to do after the conversation?A. Call up the woman for her address.B. Wait for the woman to call him again.C. Mail the woman some information.D. Wait for the woman to pick up a form.Questions 8 to 10 are based on the following conversation. At the end of the conversation you will be given 15 seconds to answer the questions.8.According to the woman, what actually makes her job difficult?A. Difficult questions from interviewees.B. Embarrassing requests from interviewees.C. Lack of professional background.D. Lack of interviewing skills.9.The woman uses all the following adjectives when talking about attending job fairs EXCEPTA. prospective.B. useful.C. important.D. tiring.10. We learn from the conversation that the womanA. works better at job fairs.B. prefers honest people.C. often works on her own.D. is experienced in her work.SECTION B PASSAGESIn this section, you will hear several passages.Listen to the passages carefully and then answer the questions that follow.Questions 11 to 13 are based on the following passage. At the end of the passage you will be given 15 seconds to answer the questions.11. According to today?s weather forecast, which part of Europe has dry weather?A. Scandinavian mountain.B. Northwestern Europe.C. Northern Europe.D. Southern Europe.12. In which part of Europe does the weather stay both fine and cool?A. Southern Europe.B. Northern Europe.C. Eastern Europe.D. Northwestern Europe.13. In which region will the weather change tomorrow?A. Northern parts of the Mediterranean.B. Eastern parts of the Mediterranean.C. Central parts of the Mediterranean.D. Southern parts of the Mediterranean.Questions 14 to 17 are based on the following passage. At the end of the passage you will be given 20 seconds to answer the questions.14.According to the passage, what benefit can technology bring to people?A. Closer contact with modern devices.B. Greater changes in social organization.C. Better understanding of mass media.D. More useful information to better their life.15.The speaker questions about everybody?s access to technological advances. The main reason is16.According to the UN plan, all the following will be achieved within ten yearsEXCEPT A. giving everyone a radio or TV.B. starting to carry out the scheme in ten years.C. offering internet service to more people.D. providing more job opportunities.17.What could be topic of the passage?A. Growth in telecommunications.B. Technology and the developing world.C. Education and medical care.D. Building an information society.Questions 18 to 20 are based on the following passage. At the end of the passage you will be given 15 seconds to answer the questions.18. People in Latin America wear something ______ to express their hopes for wealth in the New Year.A. newB. redC. whiteD. yellow 19. Which of the following NewYear?s traditions signals friendship? A. Throwing old dishes. B.Wearing something red. C. Wearing something white. D. Eatinground fruits.20. Which of the following is NOT mentioned as one?s own New Year?s tradition?A. Watching TV at home.B. Going to bed early.C. Visiting friends.D. Running and shouting outside.SECTION C NEWS BROADCASTIn this section, you will hear several news items. Listen to the passages carefully and then answerthe questions that follow.Questions 21 to 22 are based on the following news. At the end of each news item, you will be given 10 seconds to answer the questions.21.What is happening to the schools in Fairfax County this school year?A. 15 schools have started social studies.B. 15 schools have used digital textbooks.C. Students are ready to use electronic resources.D. Digital textbooks are used for social studies.22. With digital textbooks, schools have saved about ______ million dollars.A.1B.2C.3D.4Questions 23 to 24 are based on the following news. At the end of each news item, you will be given 10 seconds to answer the questions.23. Who found the suspicious item at the airport?A. TSA agents.B. FBI agents.C. The police.D. Passengers.24.Which of the following statement is INCORRECT?A. The terminal was closed temporarily afterwards.B.There was a thorough search inside the airport.C. Passengers at the airport were safe and sound.D.The security authorities identified the explosives.Questions 25 to 26 are based on the following news. At the end of each news item, you will be given10 seconds to answer the questions.25. According to the news item, doctors use art therapy to treat the following problems EXCEPTA. alcohol abuse.B. smoking.C. depression.D. schizophrenia.26. Why did doctors introduce art therapy in the first place?A. To prevent patients from smoking.B. To better understand patients.C. To get patients occupied.D. To teach patients some skills.Questions 27 to 28 are based on the following news. At the end of each news item, you will be given10 seconds to answer the questions.27.What is the main purpose of the new rules?A. To reduce the number of pilots on duty.B. To prevent pilots from working overtime.C. To ensure an adequate amount of sleep.D. To fix the amount of work for each pilot.28.The Independent Pilots Association was unhappy about the new rules becausethey A. had only covered cargo plane pilots.B. had failed to cover all the pilots.C. would be put into effect in two years.D. would be too costly if implemented.Questions 29 to 30 are based on the following news. At the end of each news item, you will be given10 seconds to answer the questions.29.Why is increase in livestock production necessary?30.What does the word“challenge”mean in the news item?A. Balance between human survival and ecology.B. Conflict between less land and more production.C. Difference between present and future needs.D. Calls by environmental critics to consume less meat.PART 3 CLOZE 15 MINDecide which of the choices given below would best complete the passage if inserted in the correspondi ng blanks. Mark the best choice for each blank on Answer Sheet Two.Everyone knows that taxation is necessary in a modern state: without it, it (31) _____ not be possible to pay the soldiers and policemen who protect us; (32) _____ the workers in government offices who (33) _____ our health, our food, our water, and all the other things that we cannot do for ourselves. (34) _____ taxation, we pay for things that we need just (35) _____ we need somewhere to live and something to eat. But (36) _____ ever yone knows that taxation is necessary, different people have different ideas about (37)____ taxation should be arranged.In most countries, a direct tax on (38) _____, which is called income tax, (39) _____. It is arranged in such (40)______ that the poorest people pay nothing, and the percentage of tax grows (41) ____ as the taxpayer's inco me grows. In some countries, for example, the tax on the richest people (42)______ as high as ninety-five per c ent! (43) _____ countries with taxation nearly (44) _____ have indirect taxation too. Many things imported into the country have to pay taxes or“ duties. Of” course, it is the men and women who buy these imported thing s in the shops (45)______ really have to pay the duties, in the (46) ______ of higher prices. In some countries, (47) _____, there is a tax on things sold in the shops. If the most necessary things are taxed, a lot of money is (48) ____ but the poor people suffer most. If unnecessary things (49)___ jewels and fur coats are taxed, less m oney is obtained but the tax is (50) ______as the rich pay it.Probably this last kind of indirect tax, together with a direct tax on incomes which is low for the poor and highf or the rich, is the best arrangement.PART 4 GRAMMAR & VOCABULARY15 MINThere are thirty sentences in this section. Beneath each sentence there are four words or phrases marked A, B, C and D. Choose one word or phrase that best completes the sentence. Mark your answers on Answer Sheet Tw o.51.Facing the board of directors, hedidn?t deny ________ breaking theagreement. A. himB. itC. hisD. its52.Xinchun returned from aboard a different man. The italicized part functions as a (n) ______.A. appositive (同位语 )B. objectC.adverbialD. complement.53.Which of the following is a compound word (复合词 )? ______.A. Nonsmoker.B. Deadline.C. Meanness.D. Misfit.54.Which of the following sentences contains subjunctive mood? ______.A. Lucy insisted that her son get home before 5o?clock?B. She used to drive to work, but now she takes the city metro.C.Walk straight ahead, and don't turn till the second traffic lights. D.Paul will cancel his flight if he cannot get his visa by Friday.55.The following determiners(限定词 ) can be used with both plural and uncountablenouns EXCEPT ______.A. moreB.enough.C.many.D.such.56.Which of the italicized parts indicates CONTRAST? ______.A. She opened the door and quietly went in.B. Victoria likes music and Sam is fond of sports.C. Think it over again and you? ll get an answer.D. He is somewhat arrogant, and I don't like this.57.Which of the following CANNOT be used as a nominal substitute(名词替代词 )? ______.A. Much.B.Neither.C.One.D.Quarter.58.All the following sentences definitely indicate future time EXCEPT ______.A.Mother is to have tea with Aunt Betty at four.B.The President is coming to the UN next week.C.The school pupils will be home by now.D.He is going to email me the necessary information.59.Which of the following sentences is grammatically INCORRECT? ______.A. Politics are the art or science of government.60.Which of in the following phrases indicates a subject-predicate relationship? ______.A. The arrival of the touristsB. The law of NewtonC. The occupation of the islandD. The plays of Oscar Wilde61.Which of the following italicized parts serves as an appositive? ______.62.Which of the following is NOT an imperative sentence? ______.A. Let me drive you home, shall I?B. You will mind your own business!C. Come and have dinner with us.D.I wish you could stay behind. ,63.If it ______ tomorrow, the match would be put off.64.Which of the following sentences expresses a fact? ______.A. Mary and her son must be home by now.B.Careless reading must give poor results.C. It?s getting late, and I must leave now.D.He must be working late at the office.65.The following are all dynamic verbs(动态动词 ) EXCEPT ______.A. remain.B. turn.C.write. D.knock.66.____ to school life was less difficult than the pupil had expected.A.AdheringB.AdoptingC.AdjustingD.Acquainting67.He is fed up with the same old dreary routine, and wants to quit his job. The underlined part means _________.A. dullB.boring C.long D.hard68.At last night?s party Larry said something that I though was beyond me. Theunderlined part means ________.A. I was unable to doC. I was unable to stopB. I couldn?t understandD. I couldn?t tolerate69. The couple ______their old house and sold it for a vast profit.A. did forB. did inC.did withD. did up70. Sally contributed a lot to the project, but she never once accepted all the ____ for herself.A.creditB.attentionC.focusD.award71.The child nodded, apparently content with his mother?s promise. The underlinedpart means _________.A. as far as one has learntB.as far as one is concerned C.as far as one can seeD. as far as one is told72.The ________ that sport builds character is well accepted by people nowadays.A.issueB.argumentC.pointD.sentence73.Everyone in the office knows that Melinda takes infinite care over her work.The underlined part means ________.A. limitedB. unnecessaryC. overdueD. much74.The new measure will reduce the chance of serious injury in the event of an accident.The underlined part means _________.A. if an accident happensB. if an accident can be preventedC. before an accidentD. during an accident75.Traditionally, local midwives would ________ all the babies in the area.A. handleB. produceC. deliverD. help76.No food or drink is allowed on the premises. The underlined part means ________.A. propositionB. advertisementC. buildingD. street77.The court would not accept his appeal unless ________ evidence is provided.A.conclusiveB.definiteC.eventualD.concluding78.As soon as he opened the door, a ________ of cold air swept through the house.A. flowB. movementC. rushD. blast79.She really wanted to say something at the meeting, but eventually ________ from it.A. preventedB. refrainedC. limitedD.restricted80.The couple told the decorator that they wanted their bedroom gaily painted. The underlined part means ___ ______. A.brightlyB. light-heartedlyC. cheerfullyD. lightlyPART V READING COMPREHENSION25 MINIn this section there are four passages followed by questions or unfinished statements, each with four sug gested answers marked A, B, C and D. Choose the one that you think is the best answer. Mark your answers on Answer Sheet Two.TEXT AThe art of public speaking began in ancient Greece over 2,000 years ago. Now, twitter, instant messaging, e-mail, blogs and chat forums offer rival approaches to communication - but none can replace the role of a greatspee ch.The spoken word can handle various vital functions: persuading or inspiring, informing, paying tribute, enterta ining, or simply introducing someone or something or accepting something. Over the past year, the human voice has helped guide us over the ups and downs of what was certainly a stormy time.Persuasion is used in dealing with or reconciling different points of view. When the leaders met in Copenhagenin December 2009, persuasive words from activists encouraged them to commit themselves to fir mer action. Inspirational speeches confront the emotions. They focus on topics and matters that are close to pe ople's hearts. During wars, generals used inspiring speeches to prepare the troops for battle.A speech that conveys knowledge and enhances understanding can inform us. The information must be clear, a ccurate, and expressed in a meaningful and interesting way. （流行病） announced, the idea of“swineflu ” many people. Informative speeches from World Health Organization officials helped people to keep their panic under control so they could take sensible precautions.Sad events are never easy to deal with but a speech that pays tribute to the loss of a loved one and gives praise for their contribution can be comforting. Madonna's speech about Michael Jackson,after his death, highlighted the fact that he will continue to live on through his music.It's not only in world forums where public speaking plays an important role. It can also be surprisingly helpful in the course of our own lives.If you?re taking part in a debate you need to persuade the listeners of the soundness ofyour argument. In sports, athletes know the importance of a pep talk （鼓舞士气的讲话） before a match to inspire teammates. You yourself may be asked to do a presentation at college or work t o inform the others about an area of vital importance.On a more personal level, a friend may be upset and need comforting. Or you might beasked to introduce a speaker at a family event or to speak at a wedding, where your language will be needed to move people or make them laugh.Great speaking ability is not something we're born with. Even Barack Obama works hardto perfect every speech. For a brilliant speech, there are rules that you can put to good use. To learn those rules you have to practice and learn from some outstanding speeches in the past.81.The author thinks the spoken word is still irreplaceable because ______.A. it has always been used to inspire or persuade people.B. it has a big role to play in the entertainment business.C. it plays important roles in human communication.D. it is of great use in everyday-life context.82.Which of the following statements is INCORRECT about the role of public speaking? _____A. Speeches at world forums can lead to effective solutions to world problems.B. Speeches from medical authorities can calm people down in times of pandemics.C. The morale of soldiers before a battle can be boosted by senior officers' speeches.D. Speeches paying tribute to the dead can comfort the mourners.83. Public speaking can play all the following roles EXCEPT______.A. to convince people in a debate.B. to inform people at a presentation.C. to advise people at work.D. to entertain people at a wedding.84. According to the passage, which of the following best explains the author's view on ______“great speaking ability”?85.What is the main idea of the passage? ______.A. Public speaking in international forums.B. The many uses of public speaking.C. Public speaking in daily life context.D. The rules of public speaking.TEXT BEvery business needs two things, says Skullcandy CEO Rick Alden: inspiration and desperation. In 2001, Alden had both. He'd sold two snowboarding businesses, and he was desperately bored. But he had an idea: He wan ted to make a new kind of headphone. I kept seeing people missing their cell phone calls because they were list ening to music,” he explains. Then I'm in a chairlift, I've got my headphones on, and I realize my phone is rin ging. As 1 take my gloves off and reach for my phone, I think, “ It can't be that tough to make headphones with two plugs, one for music and one for your cell phone”. Alden described what he wanted to a designer, perfe cted a prototype, and outsourced（外包） manufacturing overseas.Alden then started designing headphones into helmets, backpacks - anywhere that would make it easy to listen to music while snowboarding. “Selling into board and skate shops wasn't a big research effort,” he explains. “Those were the only guys I knew!”Alden didn?t want to be a manufacturer. And by outsourcing, he'd hoped he could get thebusiness off the ground without debt. But he was wrong. So he asked his wife,“Can I puta （抵押贷款） on the house? She said, What is the worst thing that can happen? Welose the house, we sell our cars, and we start all over again?I. definitely married the rightwoman!”For the next two years, Alden juggled mortgage payments and payments to his manufacturers“.Factories won 't ship your product till they get paid,”he says.“But it takes four or five months to get a mortgage company so upset that they knock on your door. So we paid the factory first”.Gradually, non-snowboarders began to notice the colorful headphones. In 2006, the company started selling the m in 1,400 FYE (For Your Entertainment) stores.“ We knew that nine out often people walking into that store would be learning about Skullcandy for the first time. Why would they look at brands they knew and take hom e a new brand instead? We had agreed to buy back anything we didn?t sell, but we were dealing with huge num bers. It?d kill us to take back all the productsAlden?s fears faded as Skullcandy became the No. 1 headphone seller in those stores andtripled its revenue to $120 million in one year. His key insight was that headphones weren?tgadgets; they were a fashion accessory“. In the beginning,” he says,“ that little white wire that said youha d an iPod ---that was cool. But now wearing the white bud means you?re just like everyone else. Headphones occupy this critical piece of cranial real estate and are highly visible”.Today, Skullcandy is America's second-largest headphone supplier, after Sony. With 79 employees, the compan y is bigger than Alden ever imagined.86.Alden came up with the idea of a new kind of headphone because he ______.A. was no longer in snowboarding business.B. had no other business opportunities.C. was very fond of modern music.D. saw an inconvenience among mobile users.87.The new headphone was originally designed for ______.A. snowboarders.B. motorcyclists.C.mountain hikers. D.marathon runners.88.Did Alden solve the money problem? ______.A. He sold his house and his cars.B. Factories could ship products before being paid.C. He borrowed money from a mortgage company.D. He borrowed money from his wife's family.89.What did Alden do to promote sales in FYE stores? ______.A. He spent more money on product advertising.B. He promised to buy back products not sold.C. He agreed to sell products at a discount.D. He improved the colour design of the product.90.Alden sees headphones as ______.A. a sign of self-confidence.B. a symbol of status.C. part of fashion.D. a kind of device.TEXT CI was standing in my kitchen wondering what to have for lunch when my friend Taj called.“ Sit down, ” she said. I thought she was going to tell me she had just gotten the haircut from hell. Ilaughed and said,“It can't be that bad”.But it was. Before the phone call, I had 30 years of retirement saving in a“safe” fund witha brilliant financial guru （金融大亨） .When I put down the phone, my savings weregone. I felt as if I had died and, for some unknown reason, was still breathing. SinceBernie Madoff?s arrest on charges of running a $65 million Ponzi scheme, I'veread many articles about how we investors should have known what was going on. I wishI could say I had reservations about Madoff before“the Call” , but I did not.On New Year's Eve, three weeks after we lost our savings, six of us Madoff people gathered atTaj's house for dinner. As we were sitting around the table, someone asked,“If you could haveyour money back right now, but it would mean giving up what you have learned by losing it,would you take the money or would you take what losing the money has given you?”My husband was still in financial shock. He said, “ I just want the money back.” I wasn't certain where I sto od. I knew that losing our money had cracked me wide open.?dI been walking around like what the Buddhists call a hungry ghost: always focused on the bite that was yet to come, not the one in my mouth. No matter how much I ate or had or experienced, it didn?t satisfy me, because I wasn?t really taking it in, wasn't absorbing it. Now I was forced to pay attention. Still, I couldn't honestly say that if someone had offered me the money bac k, I would turn it down.But the other four all said that what they were seeing about themselves was incalculable, andthey didn?t think it would have become apparent without the ground of financial stability beingripped out from underneath them.My friend Michael said,I ?d started to get complacent. It?s as if the muscles of my heart started to atrophy（萎缩） . Now they?re awake, alive— and I don?t want to go back.”Theseweren?tjust empty words. Michael and his wife needed to take in boarders to meet their expenses. Taj was so broke tha t she was moving into someone?s garage apartment in three weeks. Three friends had declared bankruptcy andweren't sure where or how they were going to live.91.What did the author learn from Taj?s call?A. had got an awful haircut.B. They had lost their retirement savings.C. Taj had just retired from work.D. They were going to meet for lunch.92.How did the author feel in the following weeks?A. Angry.B.Disappointed.C.Indifferent.D.Desperate.93.According to the passage, to which was she“ forced to pay attention”?A. Her friends.B. Her husband.C.Her lost savings. D.Her experience.94.Which of the following statements is CORRECT about her friends?A. Her friends valued their experience more.B. Her friends felt the same as she did.C. Her friends were in a better financial situation.D Her friends were more optimistic than she.95.What is the message of the passage?A. Desire for money is human nature.B. One has to be decisive during crises.C. Understanding gained is more important than money lost.D. It is natural to see varied responses to financial crises.TEXT DIn the 19th century, there used to be a model of how to be a good person. There are all these torrents of passion flowing through you. Your job, as captain of your soul, is to erect dams to keep these passions in check. Your jo b is to just say no to laziness, lust, greed, drug use and the other sins.These days that model is out of fashion. You usually can?t change your behaviour by simply resolving to doso mething. Knowing what to do is not the same as being able to do it.Your willpower is not like a dam that can block the torrent of self-indulgence. It's more like a muscle, which ti res easily. Moreover, you're a social being. If everybody around you is overeating, you?ll probably do so, too. The 19th-century character model was based on an understanding of free will. Today, weknow that free will is bounded. People can change their lives, but ordering change is notsimple because many things, even within ourselves, are beyond our direct control.Much of our behaviour, for example, is guided by unconscious habits. Researchers atDuke University calculated that more than 40 percent of the actions we take are governed byhabit, not actual decisions. Researchers have also come to understand the structure of habits—cue, routine, reward.You can change your own personal habits. If you leave running shorts on the floor atnight, that'll be a cue to go running in the morning. Don?t try to ignore your afternoon snackcraving. Every time you feel the cue for a snack, insert another routine. Take a walk.Their research thus implies a different character model, which is supposed to manipulate。

大学生英语竞赛2013答案

2013 National English Contestfor College Students(Level D - Preliminary)参考答案及评分标准Part I Listening Comprehension（30 marks）Section A (5 marks) 1—5 BABAB Section B (10 marks) 6—10 CBBAC 11—15 BAABC SectionC (5 marks) 16—20 BCCAB SectionD (10 marks)21.notably unusual 22. not necessarily 23. well known 24. set difficult goals 25. measure26. individuals 27. believe in 28. position 29. obstacles 30. be inspiredPart II V ocabulary and Structure (15 marks)31—35 CCABD 36—40 BACBD 41—45 DBCAAPart 陨陨陨Cloze (10 marks)46. of 47. divided 48. raising 49. exceptions 50. however51. including 52. greatly 53. as 54. century 55. whatPart IV Reading Comprehension (40 marks) Section A (10 marks)56. B 57. C 58. A 59. thought/thinking 60. artificial intelligence/AI Section B (10 marks)61. F 62. F 63. T64. Martial arts and acrobatics.65. When he began playing for laughs. Section C (10 marks)66. Unwanted, annoying, disorganized, or meaningless.67. Organization and complexity entwine and influence the piece in combination with each other and withother factors.68. The ideal level is a point where the complexity of a piece and the way it is organized are matchedperfectly with a listener蒺s knowledge and experience.69. 美肯定不仅仅局限于外表。

九天国际教育GCSE真题June 2013 (v3) QP - Paper 2 CIE Chemistry IGCSE

READ THESE INSTRUCTIONS FIRSTWrite your Centre number, candidate number and name in the spaces at the top of this page.Write in dark blue or black pen.You may need to use a pencil for any diagrams, graphs or rough working.Do not use staples, paper clips, highlighters, glue or correction ﬂ uid.DO NOT WRITE IN ANY BARCODES.Answer all questions.Electronic calculators may be used.A copy of the Periodic Table is printed on page 16.You may lose marks if you do not show your working or if you do not use appropriate units.At the end of the examination, fasten all your work securely together.The number of marks is given in brackets [ ] at the end of each question or part question.CHEMISTRY0620/23Paper 2May/June 20131 hour 15 minutesCandidates answer on the Question Paper.No Additional Materials are required.UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certiﬁ cate of Secondary EducationThis document consists of 14 printed pages and 2blank pages.[Turn overIB13 06_0620_23/3RP © UCLES 2013*4714033593*0620/23/M/J/13© UCLES 2013For Examiner’sUse1T he structures of ﬁ ve atoms, A , B , C , D and E , are shown below.ABCDE(a) A nswer the following questions about these structures. Each structure can be used once,more than once or not at all.(i) W hich two structures are hydrogen atoms? ............. and ............. (ii) W hich structure represents an atom of a metal?.............(iii) W hich structure has a proton (atomic) number of 3? ............. (iv) W hich structure has two neutrons in its nucleus? .............[5](b) T he structure of carbon-12 can be written C 612.W rite the structure of atom D in a similar way.[1](c) C omplete the following sentences about isotopes using words from the list below.atoms energy iron moleculesneutrons protons radioactive stableI sotopes are atoms of the same element with the same number of ....................... and different numbers of ....................... . Some isotopes such as uranium-235 are ........................ . Uranium-235 can be used as a source of ....................... .[4][Total: 10]For2The table shows some physical properties of the Group VII elements.Examiner’sUse Array(a)U se the information in the table to explain why(i)c hlorine is a gas at room temperature, ...................................................................... (1)(ii)b romine is a liquid at room temperature. ................................................................... (1)(b)D escribe the trend in atomic radius going down the group from chlorine to iodine. (1)(c)S uggest a value for the atomic radius of ﬂ uorine. (1)(d)D escribe the colour of chlorine. (1)(e)A chlorine atom has 17 electrons.Complete the following structure to show how the electrons are arranged.[2](f)C hlorine reacts with potassium bromide to form potassium chloride and bromine.(i)C omplete the symbol equation for this reaction.+ .......KBr → 2KC l + . (2)C l2(ii)E xplain why iodine does not react with potassium bromide. (1)[Total: 10]© UCLES 2013[Turn over0620/23/M/J/13ForExaminer’sUse3A luminium and gallium are in Group III of the Periodic Table.(a)T he heat from your hand is sufﬁ cient to melt gallium.D escribe the change in state from solid to liquid in terms of the kinetic particle theory.I n your answer include●t he difference in arrangement and closeness of the particles in a solid and a liquid,●t he difference in the motion of the particles in a solid and a liquid............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................. (5)(b)G allium is a metal. Describe three physical properties of gallium which are typical ofmost metals.1........................................................................................................................................2........................................................................................................................................3. (3)(c)W hen it is a gas, gallium(III) chloride has the structure shown below.Ga C lC l C lC lGaC lC lW rite the molecular formula for gallium(III) chloride. (1)0620/23/M/J/13© UCLES 2013ForExaminer’sUse (d)A luminium is used to make high voltage electricity cables.T he table shows some properties of four metals which could be used for overhead powercables.metal relativestrengthdensity ing/cm3relative electricalconductivityprice$ per tonnealuminium9 2.700.42120copper308.920.79600tungsten10019.350.2450steel507.860.1700(i)S uggest why aluminium, rather than tungsten, is used in overhead power cables? (1)(ii)S uggest why steel, rather than copper, is used as a core for overhead power cables. (1)(iii)G ive two reasons why aluminium is used for overhead power cables rather than copper.1.................................................................................................................................2. (2)(e)S tate one use of aluminium other than as an electrical conductor. (1)[Total: 14]0620/23/M/J/13© UCLES 2013[Turn overFor4I mpure water needs to be treated if it is to be used in the home.Examiner’sUse(a) (i)E xplain why ﬁ ltration and chlorination are used in the water treatment process......................................................................................................................................................................................................................................................................... (2)(ii)S tate one use of water in the home. (1)(b)D escribe a chemical test for water.....................................................................................................................................test (2)result(c) (i)C omplete the diagram below to show the electron arrangement in a water molecule.[1](ii)I s the bonding in water covalent or ionic?G ive a reason for your answer. (1)(d)P ure water is neutral. Which one of these pH values is neutral?P ut a ring around the correct answer.pH 0 pH 6 pH 7 pH 9 pH 13[1](e)W ater reacts with sodium. The products are sodium hydroxide and hydrogen.W rite a word equation for this reaction.[1][Total: 9]© UCLES 20130620/23/M/J/130620/23/M/J/13© UCLES 2013[Turn overForExaminer’sUse5 E nergy is given out when fuels burn.(a) S tate the name given to a chemical reaction which releases energy...................................................................................................................................... [1] (b) H ydrogen can be used as a fuel.C omplete the symbol equation for the burning of hydrogen in oxygen........H 2 + ....... → 2H 2O [2] (c) G asoline is a mixture of hydrocarbons containing between 5 and 10 carbon atoms.F our of these hydrocarbons are shown below.C HHH C HH C HH AC HH C HH HC HHH C HH C HH B C H H C HH C HH C HH C HH HC HHH C HH C HH CC HH C HH C HH HC HHH C HH C HH D C HH C HH C HH C HH H(i) W hich one of these structures, A , B , C or D , has the highest relative molecularmass?Y ou are not expected to do any calculations. (1)(ii) G ive one use of gasoline. (1)0620/23/M/J/13© UCLES 2013For Examiner’sUse(d) T he table shows the boiling points of the straight-chain hydrocarbons in the gasolinefraction.(i) O n the grid below, plot a graph to show how the boiling point changes with thenumber of carbon atoms in these hydrocarbons. Draw a smooth curve through the points.567891018016014012010080604020boiling point / °Cnumber of carbon atoms[3](ii)U se your graph to deduce the boiling point of the hydrocarbon with 7 carbon atoms.boiling point ............... °C [1]For(e)T he alkanes are a homologous series of hydrocarbons.Examiner’sUse(i)W hat is meant by the term homologous series?.................................................................................................................................... (2)(ii)A lkanes can be cracked to form alkenes and smaller alkanes.S tate the conditions needed for cracking..................................................................................................................................... (2)[Total: 13]© UCLES 2013[Turn over0620/23/M/J/130620/23/M/J/13© UCLES 2013For Examiner’sUse6 I nks are mixtures of different dyes.(a) A student used paper chromatography to separate the dyes in a particular ink.D escribe how paper chromatography is carried out. You may draw a diagram to help explain your answer. I n your description include● the apparatus you would use,●how chromatography is carried out............................................................................................................................................ ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] (b) The chromatogram below shows the results of a chromatography experiment. X , Y and Z are pure dyes containing only one compound.T he dyes present in four different inks, D , E , F and G are also shown.(i) W hich ink, D , E , F or G , contains all the dyes X , Y and Z ? (1)(ii) W hich ink, D ,E ,F orG , does not contain any of the dyes X , Y and Z ? (1)(iii) W hich ink contains the greatest number of different dyes? (1)ForExaminer’sUse(c) S ome inks contain ethanoic acid.C omplete the structure of ethanoic acid.[1](d) E thanoic acid can be used as a solvent.W hat is the meaning of the term solvent ? (1)(e) T he structure of a dye called Gambine R is shown below.C HO CCHH HNOHC C C C CCHC H(i) How many different types of atom are there in one molecule of Gambine R? (1)(ii) H ow many carbon atoms are there in one molecule of Gambine R? (1)[Total: 11]ForExaminer’sUse7 H ydrogen peroxide, H 2O 2, decomposes in the presence of an enzyme called peroxidase. The products of this reaction are water and oxygen.(a) (i) W hat is meant by the term enzyme ?.................................................................................................................................... (2)(ii) C omplete the symbol equation for this reaction........H 2O 2 → 2H 2O + O 2 [1] (b) A student followed the course of this reaction by measuring the volume of oxygenreleased over a period of time.T he diagram below shows some results that he obtained using hydrogen peroxide at three different concentrations.20406080100403020100volume of oxygen / cm 3time / secondsconcentration of H 2O 20.4 mol / dm 30.2 mol / dm 30.1 mol / dm 3(i) D escribe how the concentration of hydrogen peroxide affects the rate of this reaction............................................................................................................................... [1] (ii) O n the graph above, draw a line to show the course of the reaction when the startingconcentration of hydrogen peroxide is 0.3 mol / dm 3. [2] (iii)F or the concentration of hydrogen peroxide of 0.4 mol / dm 3, deduce●the volume of oxygen given off when the reaction is complete,........................ cm 3●the time it takes to produce 14 cm 3 of oxygen......................... seconds [2]ForExaminer’sUse(c) I n the presence of sulfuric acid, hydrogen peroxide reacts with iodide ions to form iodineand water. This involves the reduction of hydrogen peroxide.(i) W hat is the meaning of the term reduction ?.............................................................................................................................. [1] (ii) C omplete the word equation for the reaction of sulfuric acid with calcium hydroxide.sulfuric acid + calcium hydroxide → ............................ + ............................ (2)(iii) D escribe a test for iodide ions.test .............................................................................................................................result (2)[Total: 13]16Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the publisher will be pleased to make amends at the earliest possible opportunity.University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.G ro u p140C eC e r i u m 58141P rP r a s e o d y m i u m 59144N d N e o d y m i u m 60P mP r o m e t h i u m61150S mS a m a r i u m62152E uE u r o p i u m63157G dG a d o l i n i u m64159T bT e r b i u m65162D yD y s p r o s i u m66165H oH o l m i u m67167E rE r b i u m68169T mT h u l i u m69173Y bY t t e r b i u m70175L uL u t e t i u m71232T hT h o r i u m 90P aP r o t a c t i n i u m 91238UU r a n i u m92N pN e p t u n i u m93P uP l u t o n i u m94A mA m e r i c i u m95C mC u r i u m96B kB e r k e l i u m97C fC a l i f o r n i u m98E sE i n s t e i n i u m99F mF e r m i u m100M dM e n d e l e v i u m101N oN o b e l i u m102L rL a w r e n c i u m1031HH y d r o g e n17L iL i t h i u m 323N aS o d i u m 1124M gM a g n e s i u m1240C aC a l c i u m 2045S c S c a n d i u m 2148T i T i t a n i u m2251V V a n a d i u m 2352C r C h r o m i u m 2455M n M a n g a n e s e 2556F e I r o n 2659C o C o b a l t 2759N i N i c k e l 2864C u C o p p e r 2965Z nZ i n c3070G aG a l l i u m3127A lA l u m i n i u m1311B B o r o n 512C C a r b o n614NN i t r o g e n716OO x y g e n819FF l u o r i n e928S iS i l i c o n1431PP h o s p h o r u s1532SS u l f u r1635.5C lC h l o r i n e1740A rA r g o n1820N eN e o n104H eH e l i u m273G eG e r m a n i u m3275A sA r s e n i c3379S eS e l e n i u m3480B rB r o m i n e3584K rK r y p t o n3639KP o t a s s i u m 1988S rS t r o n t i u m 3889Y Y t t r i u m 3991Z r Z i r c o n i u m4093N b N i o b i u m 4196M o M o l y b d e n u m 42T c T e c h n e t i u m 43101R u R u t h e n i u m 44103R h R h o d i u m 45106P d P a l l a d i u m 46108A gS i l v e r47112C dC a d m i u m48115I nI n d i u m49119S nT i n50122S bA n t i m o n y51128T eT e l l u r i u m52127II o d i n e53131X eX e n o n54137B aB a r i u m 56139L a L a n t h a n u m 57*178H fH a f n i u m72181T a T a n t a l u m 73184W T u n g s t e n 74186R e R h e n i u m 75190O s O s m i u m 76192I rI r i d i u m 77195P t P l a t i n u m78197A uG o l d79201H gM e r c u r y80204T lT h a l l i u m81207P bL e a d82209B iB i s m u t h83P oP o l o n i u m84A tA s t a t i n e85R nR a d o n86F rF r a n c i u m 87227A cA c t i n i u m899B eB e r y l l i u m4II I I I II V V V I V I I 085R bR u b i d i u m 37133C sC a e s i u m 55226R a R a d i u m 88T h e v o l u m e o f o n e m o l e o f a n y g a s i s 24d m 3a t r o o m t e m p e r a t u r e a n d p r e s s u r e (r .t .p .).a Xb a = r e l a t i v e a t o m ic m a s sX = a t o m i c s y m b o lb = p r o t o n (a t o m ic ) n u m b e rK e y *58-71 L a n t h a n o i d s e r i e s 90-103 A c t i n o i d s e r i e s D A T A S H E E T T h e P e r i o d i c T a b l e o f t h e E l e m e n t sPMT。

Igcse-数学-历年真题

I g c s e-数学-历年真题-2(总25页)-CAL-FENGHAI.-(YICAI)-Company One1-CAL-本页仅作为文档封面，使用请直接删除4400/4HEdexcel IGCSEMathematicsPaper 4HHigher TierFriday 11 June 2010 – AfternoonTime: 2 hoursMaterials required for examination Items included with question papersRuler graduated in centimetres and Nilmillimetres, protractor, compasses,pen, HB pencil, eraser, calculator.Tracing paper may be used.Instructions to CandidatesIn the boxes above, write your centre number, candidate number, your surname, initials and signature.Check that you have the correct question paper.Answer ALL the questions. Write your answers in the spaces provided in this question paper.You must NOT write on the formulae page. Anything you write on the formulae page will gain NO credit.If you need more space to complete your answer to any question, use additional answer sheets. Information for CandidatesThe marks for individual questions and the parts of questions are shown in round brackets: e.g. (2). There are 22 questions in this question paper. The total mark for this paper is 100.You may use a calculator.Advice to CandidatesWrite your answers neatly and in good English.N36905AIGCSE MATHEMATICS 4400 FORMULA SHEET – HIGHER TIERAnswer ALL TWENTY TWO questions.Write your answers in the spaces provided.You must write down all stages in your working.1. Solve 6 y – 9 = 3 y + 7y = ................................(Total 3 marks) 2. The diagram shows two towns, A and B, on a map.(a) By measurement, find the bearing of B from A.....................................︒(2)C is another town.The bearing of C from A is 050︒.(b) Find the bearing of A from C.....................................︒(2)(Total 4 marks)3. A spinner can land on red or blue or yellow.The spinner is biased.The probability that it will land on red is 0.5The probability that it will land on blue is 0.2Imad spins the spinner once.(a) Work out the probability that it will land on yellow......................................(2)Janet spins the spinner 30 times.(b) Work out an estimate for the number of times the spinner will land on blue......................................(2)(Total 4 marks)4. Rosetta drives 85 kilometres in 1 hour 15 minutes.(a) Work out her average speed in kilometres per hour...................................... km/h(2)Rosetta drives a total distance of 136 kilometres.(b) Work out 85 as a percentage of 136................................. %(2)Sometimes Rosetta travels by train to save money.The cost of her journey by car is £12The cost of her journey by train is 15% less than the cost of her journey by car.(c)Work out the cost of Rosetta’s journey by train.£ ...................................(3)(Total 7 marks)5.Calculate the value of x.Give your answer correct to 3 significant figures.x = ................................(Total 3 marks)6. A = {2, 3, 4, 5}B = {4, 5, 6, 7}(a)(i) List the members of A ⋂B......................................(ii) How many members are in A ⋃B.....................................(2)ℰ = {3, 4, 5, 6, 7}P = {3, 4, 5}Two other sets, Q and R, each contain exactly three members.P ⋂Q = {3, 4}P ⋂R = {3, 4}Set Q is not the same as set R.(b)(i) Write down the members of a possible set Q......................................(ii) Write down the members of a possible set R......................................(2)(Total 4 marks)7. Rectangular tiles have width (x + 1) cm and height (5x – 2) cm.Some of these tiles are used to form a large rectangle.The large rectangle is 7 tiles wide and 3 tiles high.The perimeter of the large rectangle is 68 cm.(a) Write down an equation in x...............................................................................................................(3)(b) Solve this equation to find the value of x.x = ................................(3)(Total 6 marks)8. Show that 121 141 = 1519.The depth of water in a reservoir increases from 14 m to 15.75 m. Work out the percentage increase.................................. %(Total 3 marks)10. Quadrilaterals ABCD and PQRS are similar.AB corresponds to PQ.BC corresponds to QR.CD corresponds to RS.Find the value of(a) xx = ...............................(2)(b) yy = ...............................(1)(Total 3 marks)11. Simplify fully6x + 43x.....................................(Total 3 marks)12.(a)Find the equation of the line L......................................(3)(b) Find the three inequalites that define the unshaded region shown in the diagram below................................................................................................................(3)(Total 6 marks)13. (a) Solve x 2– 8x + 12 = 0.....................................(3)(b) Solve the simultaneous equationsy = 2x4x – 5y = 9x = ................................y = ................................(3)(Total 6 marks)14.The area of the triangle is 6.75 cm2.The angle x°is acute.Find the value of x.Give your answer correct to 1 decimal place.x = ................................(Total 3 marks)15. The unfinished histogram shows information about the heights, h metres, of some trees.(a) Calculate an estimate for the number of trees with heights in the interval 4.5 < h ≤ 10.....................................(3)(b) There are 75 trees with heights in the interval 10 < h ≤ 13Use this information to complete the histogram.(2)(Total 5 marks)16. A bag contains 3 white discs and 1 black disc.John takes at random 2 discs from the bag without replacement.(a) Complete the probability tree diagram.First disc Second disc(3)(b)Find the probability that both discs are white......................................(2)All the discs are now replaced in the bag.Pradeep takes at random 3 discs from the bag without replacement.(c)Find the probability that the disc left in the bag is white......................................(3)(Total 8 marks)17. The diagram shows a sector of a circle, radius 45 cm, with angle 84°.Calculate the area of the sector.Give your answer correct to 3 significant figures.............................. cm2(Total 3 marks) 18.Calculate the length of AC.Give your answer correct to 3 significant figures................................ cm(Total 3 marks)19. A cone has slant height 4 cm and base radius r cm.The total surface area of the cone is 433π cm 2.Calculate the value of r .r = ................................(Total 4 marks)20. f(x) = (x – 1)2(a) Find f(8).....................................(1)The domain of f is all values of x where x ≥ 7(a)Find the range of f......................................(2)xg(x) =x1(c) Solve the equation g(x) = 1.2.....................................(2)(d) (i) Express the inverse function g –1 in the form g –1(x) = .......g –1(x) = ...................................(ii) Hence write down gg(x) in terms of x.gg(x) = ....................................(6)(Total 11 marks)21.In the diagram = a and = c.(a) Find CA in terms of a and c......................................(1)The point B is such that AB=1c.2(b) Give the mathematical name for the quadrilateral OABC......................................(1)The point P is such that = a + k c, where k ≥ 0(c) State the two conditions relating to a + k c that must be true for OAPC to be a rhombus.(2)(Total 4 marks)22. (a) Work out 5.2 × 102 + 2.3 × 104Give your answer in standard form......................................(2)a × 102 +b × 104 =c × 104(b) Express c in terms of a and b.c = ................................(2)(Total 4 marks)TOTAL FOR PAPER = 100 MARKSEND。

九天国际教育GCSE真题June 2013 (v3) QP - Paper 1 CIE Chemistry IGCSE

This document consists of 15 printed pages and 1 blank page.IB13 06_0620_13/FP© UCLES 2013[Turn over*3600035500*UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary EducationCHEMISTRY 0620/13Paper 1 Multiple Choice May/June 201345 MinutesAdditional Materials: Multiple Choice Answer Sheet Soft clean eraserSoft pencil (type B or HB is recommended)READ THESE INSTRUCTIONS FIRSTWrite in soft pencil.Do not use staples, paper clips, highlighters, glue or correction fluid.Write your name, Centre number and candidate number on the Answer Sheet in the spaces provided unless this has been done for you.DO NOT WRITE IN ANY BARCODES.There are forty questions on this paper. Answer all questions. For each question there are four possible answers A , B , C and D .Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet.Read the instructions on the Answer Sheet very carefully.Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. A copy of the Periodic Table is printed on page 16. Electronic calculators may be used.© UCLES 2013 0620/13/M/J/131 The diagram shows a cup of tea.Wh ich row describes th e water particles in th e air above th e cup compared with th e water particles in the cup?moving fastercloser togetherA B C D2 Crystals of sodium chloride were prepared by the following method.1 25.0 cm 3 of dilute hydrochloric acid was accurately measured into a conical flask.2 Aqueous sodium hydroxide was added until the solution was neutral. The volume of sodium hydroxide added was measured.3The solution was evaporated and the crystals washed with approximately 15 cm 3 of water.Which row shows the pieces of apparatus used to measure the 25.0 cm 3 of hydrochloric acid, the volume of aqueous sodium hydroxide and the 15 cm 3 of water?25.0 cm3 of hydrochloricacid accuratelythe volume of aqueous sodium hydroxide added15 cm 3 of water approximatelyA burette pipette measuring cylinderB measuring cylinderburettepipetteC pipette burette measuring cylinder Dpipette measuring cylinder burette© UCLES 2013 0620/13/M/J/13[Turn over3 The positions of four elements are shown on the outline of the Periodic Table. Which element forms a coloured oxide?ABCD4 Lead iodide is insoluble in water.Lead iodide is made by adding aqueous lead nitrate to aqueous potassium iodide.Which pieces of apparatus are needed to obtain solid lead iodide from 20 cm 3 of aqueous lead nitrate?12345A 1, 2 and 4B 1, 3 and 5C 1, 4 and 5D 2, 4 and 55 Element X is represented by X 2713.Which statement about element X is correct?A An atom of X contains 13 protons and 13 neutrons.B An atom of X contains 27 protons and 13 electrons. CX forms an ion by gaining electrons.D X is placed in Group III of the Periodic Table.© UCLES 2013 0620/13/M/J/136 Element X has six electrons in its outer shell.= electronkeyeHow could the element react?A by gaining two electrons to form a positive ionB by losing six electrons to form a negative ionC by sharing two electrons with two electrons from another element to form two covalent bondsD by sharing two electrons with two electrons from another element to form four covalent bonds 7 For which substance is the type of bonding not correct?type of bondingsubstanceionic covalent metallicAc h lorineB potassium bromideC sodiumD sodium chloride8 A compound with the formula XF 2 has a relative formula mass of 78.What is element X? A argon B calcium C neonD zirconium9The diagram shows an incomplete circuit.Which substance causes the lamp to light when added to the glass tube?A aqueous sodium chlorideB aqueous sugarC solid sodium chlorideD solid sugar10 The diagram shows an electrical cable.metal coreWhich statement about the substances used is correct?A The coating is plastic because it conducts electricity well.B The core is copper because it conducts electricity well.C The core is copper because it is cheap and strong.D The core is iron because it is cheap and strong.11What is the balanced chemical equation for the reaction between calcium and water?A Ca + H2O → CaOH + H2B Ca + H2O → Ca(OH)2 + H2C Ca + 2H2O → CaOH + H2D Ca + 2H2O → Ca(OH)2 + H2© UCLES 2013 0620/13/M/J/13 [Turn overII) sulfate powder is put into a beaker of water and stirred.What would show that the process was exothermic?A A blue solution is formed.B The beaker feels cooler.C The beaker feels warmer.D The powder dissolves in the water.13 The diagram shows an electrolysis circuit.At which electrode is hydrogen formed?sodium chloride sodium chloride14Which substance does not require oxygen in order to produce energy?A coalB hydrogenC natural gasD 235U15Calcium carbonate reacts with hydrochloric acid to form carbon dioxide.Which changes would slow this reaction down?1 decreasing the concentration of hydrochloric acid2 decreasing the particle size of calcium carbonate3 decreasing the temperatureA 1 and 2 onlyB 1 and 3 onlyC 2 and 3 only D1, 2 and 3© UCLES 2013 0620/13/M/J/13© UCLES 2013 0620/13/M/J/13[Turn over16 The equation shows the formation of anhydrous copper(II ) sulfate from hydrated copper(II )sulfate.CuSO 4.5H 2O CuSO 4 + 5H 2OStatements 1, 2 and 3 refer to this reaction.1 Hydrated copper(II ) sulfate is reduced to anhydrous copper(II ) sulfate.2 The (II ) in the name copper(II ) sulfate refers to the oxidation state of the metal. 3The reaction is reversible.Which statements are correct?A 1 onlyB 1 and 2C 2 and 3D 3 only17 Ant stings hurt because of the methanoic acid produced by the ant.Which substance could, most safely , be used to neutralise the acid?substance pH A baking soda 8 B car battery acid 1 C lemon juice 3 Doven cleaner1418 In which equation is the underlined substance acting as a reducing agent?A 3CO + Fe 2O 3 → 2Fe + 3CO 2B CO 2 +C → 2CO C CuO + H 2 → Cu + H 2OD CaO + H 2O → Ca(OH)2© UCLES 2013 0620/13/M/J/13and in alkaline solutions.indicator acidalkali bromophenol blueyellow blue Congo redvioletredA few drops of each indicator are added to separate samples of a solution of pH 2.What are the colours of the indicators in this solution?in a solution of pH 2bromophenol blue isCongo red isA blue redB blue violetC yellow red Dyellow violet20 The diagram shows an experiment.redlitmus paperaqueous+aqueoussodium hydroxideWhat happens to the pieces of litmus paper?blue litmus paper red litmus paper A changes colour changes colour B changes colour no colour change C no colour change changes colour D no colour changeno colour change21The diagram shows one period of the Periodic Table.Li Be B C NO F Ne Which two elements form acidic oxides?A carbon and lithiumB carbon and neonC carbon and nitrogenD nitrogen and neon22Which element is a transition metal?colour of chloride melting point of element/°CA white 113B white 1495C yellow 113D yellow 149523Which property of elements increases across a period of the Periodic Table?A metallic characterB number of electron shellsC number of outer shell electronsD tendency to form positive ions24Which property makes aluminium ideal for making food containers?A conducts electricityB conducts heatC mechanical strengthD resistance to corrosion© UCLES 2013 0620/13/M/J/13 [Turn over© UCLES 2013 0620/13/M/J/1325 Fluorine is at the top of Group VII in the Periodic Table.Which row shows the properties of fluorine?colourstate at roomtemperature reaction with aqueous potassium iodideA brown gas no reactionB brown liquid iodine displacedC yellow gas iodine displaced Dyellow liquid no reaction26 Which element is a metal?charge on element ionelectrical conductivityA negative lowB positive highC negative high Dpositive low27 Group I metals are also known as the Alkali Metals.Which statement about the metals in Group I is not correct?A In their reactions they lose electrons.B Their atoms all have one electron in their outer shell.C They form +1 ions in their reactions with non-metals.D They form covalent compounds by sharing electrons.28Below are some metals in decreasing order of reactivity.magnesiumzincironcopperTitanium reacts with acid and cannot be extracted from its ore by heating with carbon.Where should titanium be placed in this list?A below copperB between iron and copperC between magnesium and zincD between zinc and iron29Which substance is not involved in the extraction of iron from hematite?A carbonB carbon monoxideC calcium carbonateD nitrogen30Pure metals conduct electricity and can be hammered into different shapes.Why are metals sometimes used as alloys?A Alloys are cheaper than the metals they are made from.B Alloys are easier to hammer into different shapes.C Alloys are harder and keep their shape better.D Alloys conduct electricity better.31Water has been contaminated with sea-water.Which substances can be removed by chlorination and filtration?A bacteria, sand and sodium chlorideB bacteria and sand onlyC bacteria and sodium chloride onlyD sand and sodium chloride only32 Which information about carbon dioxide and methane is correct?carbon dioxide methaneA formed when vegetation decomposes keyB greenhouse gas = trueC present in unpolluted air = falseDproduced during respiration33 Iron rusts when it reacts with ……1……Rusting can be prevented by covering the iron with a more reactive metal, such as ……2……Which words correctly complete gaps 1 and 2?1 2A oxygen copperB oxygen magnesiumC oxygen and water copper Doxygen and watermagnesium34 Nitrogen, phosphorus and potassium are essential elements for plant growth.Which mixture provides all three essential elements?mixtureformula Aammonium phosphate+potassium chloride (NH 4)3PO 4+ KC l Bammonium phosphate+ammonium nitrate (NH 4)3PO 4+ NH 4NO 3 Cammonium phosphate+ammonium chloride (NH 4)3PO 4+ NH 4C l Dammonium nitrate+potassium chlorideNH 4NO 3+ KC l35 Organic compounds may have names ending in -ane, -ene, -ol or -oic acid.How many of these endings indicate the compounds contain double bonds in their molecules? A 1 B 2 C 3 D 436 The list shows four methods that were suggested for the formation of carbon dioxide.1 action of an alkali on a carbonate2 action of heat on a carbonate3 complete combustion of methane 4reaction of a carbonate with oxygenWhich methods would result in the production of carbon dioxide?A 1 and 2B 1 and 4C 2 and 3D 3 and 437 The table shows the boiling points of four members of the homologous series of alcohols.compoundname formula boiling point/ °Cmethanol CH 3O H 65 ethanol C 2H 5O H 78 propanol C 3H 7O H X butanol C 4H 9O H 117What is the value of X?A 55 °CB 82 °C C 98 °CD 115 °C38 Which columns describe the hydrocarbons ethane and ethene?1 2 3 4 state at room temperature gas gas liquid liquid reaction with oxygen burns burns burns burns reaction with aqueous bromineno reactiondecolourises bromineno reactiondecolourises bromineA 1 (ethane) and 2 (ethene)B 1 (ethane) and 4 (ethene)C 2 (ethene) and 3 (ethane)D 3 (ethane) and 4 (ethene)39The table shows some fractions that are obtained from petroleum by fractional distillation, together with some of their uses.fraction userefinery gas cookinggasoline fuel for cars1 makingchemicalsfuel2 jet3 fuel for shipsroadsbitumen makingWhich row correctly identifies fractions 1, 2 and 3?1 2 3A diesel oil fuel oil lubricating fractionB fuel oil diesel oil keroseneoilC kerosene naphtha dieseloilD naphtha kerosene fuel40 Which of the statements about ethanol are correct?1 Ethanol can be formed by an addition reaction.2 Ethanol can be formed by fermentation.3 When ethanol burns in air, it forms carbon dioxide and water.A 1, 2 and 3B 1 and 2C 1 and 3D 2 and 3BLANK PAGE16Per mission to r epr oduce items wher e thir d-par ty owned mater ial pr otected by copyr ight is included has been sought and clear ed wher e possible. Ever y reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. G r ou p140C eC e r i u m 58141P rP r a s e o d y m i u m 59144N d N e o d y m i u m 60P mP r o m e t h i u m61150S mS a m a r i u m62152E uE u r o p i u m63157G dG a d o l i n i u m64159T bT e r b i u m65162D yD y s p r o s i u m66165H oH o l m i u m67167E rE r b i u m68169T mT h u l i u m69173Y bY t t e r b i u m70175L uL u t e t i u m71232T hT h o r i u m 90P aP r o t a c t i n i u m 91238UU r a n i u m92N pN e p t u n i u m93P uP l u t o n i u m94A mA m e r i c i u m95C mC u r i u m96B kB e r k e l i u m97C fC a l i f o r n i u m98E sE i n s t e i n i u m99F mF e r m i u m100M dM e n d e l e v i u m101N oN o b e l i u m102L rL a w r e n c i u m1031HH y d r o g e n17L iL i t h i u m 323N aS o d i u m 1124M gM a g n e s i u m1240C aC a l c i u m 2045S c S c a n d i u m 2148T i T i t a n i u m2251V V a n a d i u m 2352C r C h r o m i u m 2455M n M a n g a n e s e 2556F e I r o n 2659C o C o b a l t 2759N i N i c k e l 2864C u C o p p e r 2965Z n Z i n c3070G aG a l l i u m3127A l A l u m i n i u m1311B B o r o n 512C C a r b o n614NN i t r o g e n716OO x y g e n819FF l u o r i n e928S iS i l i c o n1431PP h o s p h o r u s1532SS u l f u r1635.5C lC h l o r i n e1740A rA r g o n1820N eN e o n104H eH e l i u m273G eG e r m a n i u m3275A sA r s e n i c3379S eS e l e n i u m3480B rB r o m i n e3584K rK r y p t o n3639KP o t a s s i u m 1988S rS t r o n t i u m 3889Y Y t t r i u m 3991Z r Z i r c o n i u m4093N b N i o b i u m 4196M o M o l y b d e n u m 42T c T e c h n e t i u m 43101R u R u t h e n i u m 44103R h R h o d i u m 45106P d P a l l a d i u m 46108A g S i l v e r47112C dC a d m i u m48115I nI n d i u m49119S nT i n50122S bA n t i m o n y51128T eT e l l u r i u m52127II o d i n e53131X eX e n o n54137B aB a r i u m 56139L a L a n t h a n u m 57*178H fH a f n i u m72181T a T a n t a l u m 73184W T u n g s t e n 74186R e R h e n i u m 75190O s O s m i u m 76192I rI r i d i u m 77195P t P l a t i n u m78197A uG o l d79201H gM e r c u r y80204T lT h a l l i u m81207P bL e a d82209B iB i s m u t h83P oP o l o n i u m84A tA s t a t i n e85R nR a d o n86F rF r a n c i u m 87227A cA c t i n i u m899B eB e r y l l i u m4II I I I II V V V I V I I 085R bR u b i d i u m 37133C sC a e s i u m 55226R a R a d i u m 88T h e v o l u m e o f o n e m o l e o f a n y g a s i s 24d m 3a t r o o m t e m p e r a t u r e a n d p r e s s u r e (r .t .p .).a Xb a = r e l a t i v e a t o m ic m a s sX = a t o m i c s y m b o lb = p r o t o n (a t o m ic ) n u m b e rK e y *58-71 L a n t h a n o i d s e r i e s 90-103 A c t i n o i d s e r i e s D A T A S H E E T T h e P e r i o d i c T a b l e o f t h e E l e m e n t sPMT。

2013全国大学生英语竞赛C类真题答案

2013National English Contestfor College Students(Level C-Preliminary)参考答案及作文评分标准Part I Listening Comprehension(30marks)Section A(5marks)1—5ABCCBSection B(10marks)6—10ABBCB11—15CABABSection C(5marks)16—20CACBBSection D(10marks)21.yearn for22.flush out23.tends to pensate forck of evidence26.separated into27.assessed28.medication29.contradictory30.wrinklesPart II Vocabulary and Structure(15marks)31—35CDCCB36—40BADCA41—45ADBCAPart III Cloze(10marks)46.hiding47.surprising48.pressure49.presidency50.existence51.with52.place53.gravity54.Additionally55.afternoonPart IV Reading Comprehension(40marks)Section A(10marks)paring58.unique59.altered60.privacySection B(10marks)61.F62.F63.T64.Pansies are more hardy than busy lizzies.65.Potentillas.Section C(10marks)66.extreme lengths/great patible with68.on condition69.C70.B Section D(10marks)71.Glaciers and forests.72.24cubic miles of ice.73.They have increased in numbers.74.阿拉斯加的大部分土地曾经是常年冰冻，或是一年中多数时间都保持冰冻状态，以此保持它的完整。

剑桥IGCSE课程数学科目试卷四

UCLES 2007
Answer(c)
0607/04/SP/10
minutes [3] [Turn over
4 2 f(x) = 5 .
1− x (a) Find f(–9).
For Examiner's
Use
(b) Solve f(x) = 2.
Answer(a)
READ THESE INSTRUCTIONS FIRST
Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. Do not use staples, paper clips, highlighters, glue or correction fluid. You may use a pencil for any diagrams or graphs.
For Examiner's
Use
Answer(a)
km/h [2]
(b) One day, the train departed at 08 50 but, due to delays, the average speed was reduced by 10%. Calculate (i) the new arrival time,
UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education
CAMBRIDGE INTERNATIONAL MATHEMATICS Paper 4 (Extended) SPECIMEN PAPER

2013年CIE剑桥国际考试IGCSE数学真题(43)

READ THESE INSTRUCTIONS FIRSTWrite your Centre number, candidate number and name on all the work you hand in.Write in dark blue or black pen.You may use a pencil for any diagrams or graphs.Do not use staples, paper clips, highlighters, glue or correction ﬂ uid.DO NOT WRITE IN ANY BARCODES.Answer all questions.If working is needed for any question it must be shown below that question.Electronic calculators should be used.If the degree of accuracy is not speci ﬁ ed in the question, and if the answer is not exact, give the answer to three signi ﬁ cant ﬁ gures. Give answers in degrees to one decimal place.For π, use either your calculator value or 3.142.At the end of the examination, fasten all your work securely together.The number of marks is given in brackets [ ] at the end of each question or part question.The total of the marks for this paper is 130.MATHEMATICS0580/43Paper 4 (Extended)May/June 20132 hours 30 minutesCandidates answer on the Question Paper.Additional Materials:Electronic calculator Geometrical instrumentsTracing paper (optional)UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certi ﬁ cate of Secondary EducationThis document consists of 19 printed pages and 1blank page.[Turn overIB13 06_0580_43/5RP © UCLES 2013*9687546924*0580/43/M/J/13© UCLES 2013ForExaminer ′s Use1 (a) A li and Ben receive a sum of money. T hey share it in the ratio 5 : 1. A li receives $2345.C alculate the total amount. Answer(a) $ (2)(b) A li uses 11% of his $2345 to buy a television.C alculate the cost of the television. Answer(b) $ (2)(c) A different television costs $330.(i) B en buys one in a sale when this cost is reduced by 15%.H ow much does Ben pay? Answer(c)(i) $ (2)(ii) $330 is 12% less than the cost last year.C alculate the cost last year. Answer(c)(ii) $ (3)0580/43/M/J/13© UCLES 2013[Turn overFor Examiner ′s Use(d) Ali invests $1500 of his share in a bank account.The account pays compound interest at a rate of 2.3% per year.Calculate the total amount in the account at the end of 3 years.Answer(d) $ (3)(e) Ali also buys a computer for $325.He later sells this computer for $250.Calculate Ali’s percentage loss.Answer(e) ........................................... % [3]_____________________________________________________________________________________0580/43/M/J/13© UCLES 2013For Examiner ′s Use2(a) I n this question show all your construction arcs and use only a ruler and compasses to drawthe boundaries of your region.T his scale drawing shows the positions of four towns, P , Q , R and S , on a map where 1 cm represents 10 km.SScale: 1 cm to 10 kmA nature reserve lies in the quadrilateral PQRS . The boundaries of the nature reserve are:● equidistant from Q and from R ● equidistant from PS and from PQ ● 60 km from R ● along QR .(i) S hade the region which represents the nature reserve. [7](ii) M easure the bearing of S from P .Answer(a)(ii) (1)0580/43/M/J/13© UCLES 2013[Turn overFor Examiner ′s Use(b) A circular lake in the nature reserve has a radius of 45 m.(i) Calculate the area of the lake.Answer(b)(i) .......................................... m 2 [2](ii)NOT TO SCALEA fence is placed along part of the circumference of the lake. This arc subtends an angle of 210° at the centre of the circle.Calculate the length of the fence.Answer(b)(ii) ........................................... m [2] _____________________________________________________________________________________For3 (a)Luk wants to buy x goats and y sheep.Examiner′sUse(i)H e wants to buy at least 5 goats.Write down an inequality in x to represent this condition.Answer(a)(i) (1)(ii)H e wants to buy at least 11 sheep.Write down an inequality in y to represent this condition.Answer(a)(ii) (1)(iii)H e wants to buy at least 20 animals.W rite down an inequality in x and y to represent this condition.Answer(a)(iii) (1)(b)G oats cost $4 and sheep cost $8.The maximum Luk can spend is $160.Write down an inequality in x and y and show that it simpliﬁ es to x + 2y Y 40 .Answer(b)[1]© UCLES 20130580/43/M/J/130580/43/M/J/13© UCLES 2013[Turn overFor Examiner ′s Use(c) (i) O n the grid below, draw four lines to show the four inequalities and shade the unwanted regions.[7](ii) Work out the maximum number of animals that Luk can buy.Answer(c)(ii) ............................................... [2]_____________________________________________________________________________________0580/43/M/J/13© UCLES 2013For Examiner ′s Use4IGEFJH40 cm22 cm7 cmNOT TO SCALEEFGHIJ is a solid metal prism of length 40 cm. The cross section EFG is a right-angled triangle. EF = 7 cm and EG = 22 cm.(a) Calculate the volume of the prism.Answer(a) ........................................ cm 3 [2](b) Calculate the length FJ .Answer(b) FJ = ......................................... cm [4]For (c)Calculate the angle between FJ and the base EGJH of the prism.Examiner′sUseAnswer(c) (3)(d)The prism is melted and made into spheres.Each sphere has a radius 1.5cm.Work out the greatest number of spheres that can be made.4πr3.]V, of a sphere with radius r is V =[Thevolume,3Answer(d) (3)(e) (i) A right-angled triangle is the cross section of another prism.This triangle has height 4.5cm and base 11.0cm.Both measurements are correct to 1 decimal place.Calculate the upper bound for the area of this triangle.Answer(e)(i) ........................................ cm2 [2] (ii)Write your answer to part (e)(i) correct to 4 signiﬁ cant ﬁ gures.Answer(e)(ii) ........................................ cm2 [1]_____________________________________________________________________________________© UCLES 2013[Turn over0580/43/M/J/130580/43/M/J/13© UCLES 2013ForExaminer ′s Use5 (a) Complete this table of values for the function f(x ) = x 1 – x 2, x ¸0.[3](b) Draw the graph of f(x ) = x 1 – x 2for –3 Y x Y –0.2 and 0.2 Y x Y3.y [5]For(c)Use your graph to solve f(x) = –3.Examiner′sUseAnswer(c) x = ................ or x = ................ or x = . (3)(d)By drawing a suitable line on your graph, solve the equation f(x) = 2x – 2.Answer(d) x = ................ or x = ................ or x = . (3)(e)B y drawing a suitable tangent, work out an estimate of the gradient of the curve at the point wherex = –2.You must show your working.Answer(e) (3)_____________________________________________________________________________________For Examiner ′s Use6 In a box there are7 red cards and 3 blue cards.A card is drawn at random from the box and is not replaced. A second card is then drawn at random from the box.(a) Complete this tree diagram.RedBlueRedBlue BlueRed........................................First cardSecond card710[3](b) Work out the probability that the two cards are of different colours.Give your answer as a fraction.Answer(b) ............................................... [3]_____________________________________________________________________________________For Examiner ′s Use7y(a) (i) Draw the image of shape A after a stretch, factor 3, x -axis invariant.[2](ii) Write down the matrix representing a stretch, factor 3, x -axis invariant.Answer(a)(ii) eo [2](b) (i) Describe fully the single transformation which maps shape A onto shape B .Answer(b)(i) (3)(ii) Write down the matrix representing the transformation which maps shape A onto shape B .Answer(b)(ii) eo [2]_____________________________________________________________________________________ForExaminer′sUse8 (a)27°BCOAED NOT TO SCALEA, B, C, D and E are points on the circle centre O.AngleABD = 27°.Find(i) angle ACD,Answer(a)(i) Angle ACD = (1)(ii) angle AOD,Answer(a)(ii) Angle AOD = (1)(iii) angle AED.Answer(a)(iii) Angle AED = (1)(b)LKN M67°100°45cm32cm NOT TO SCALEThe diagram shows quadrilateral KLMN.KL = 45cm, LN = 32cm, angle KLN = 100° and angle NLM = 67°.ForExaminer′sUse (i)Calculate the length KN.Answer(b)(i) KN = ......................................... cm [4](ii)The area of triangle LMN is 324cm2.Calculate the length LM.Answer(b)(ii) LM = ......................................... cm [3](iii) Another triangle XYZ is mathematically similar to triangle LMN.LN MXZYNOT TOSCALEXZ = 16cm and the area of triangle LMN is 324cm2.Calculate the area of triangle XYZ.Answer(b)(iii) ........................................ cm2 [2] _____________________________________________________________________________________For Examiner ′s Use9 Sam asked 80 people how many minutes their journey to work took on one day.The cumulative frequency diagram shows the times taken (m minutes).CumulativefrequencyTime (minutes)(a) Find(i) the median,Answer(a)(i) ........................................ min [1](ii) the lower quartile,Answer(a)(ii) ........................................ min [1](iii) the inter-quartile range.Answer(a)(iii) ........................................ min [1]For(b)One of the 80 people is chosen at random.Examiner′sUse Find the probability that their journey to work took more than 35 minutes.Give your answer as a fraction.Answer(b) (2)(c)Use the cumulative frequency diagram to complete this frequency table.Time (m minutes)0 < m Y 1010 < m Y 1515 < m Y 3030 < m Y 4040 < m Y 50Frequency301218[2](d)Using mid-interval values, calculate an estimate of the mean journey time for the 80 people.Answer(d) ........................................ min [3](e)U se the table in part (c) to complete the histogram to show the times taken by the 80 people.O ne column has already been completed for you. Array FrequencydensitymTime (minutes)[5]_____________________________________________________________________________________For Examiner ′s Use10 (a) (i) Solve 2(3x – 7) = 13.Answer(a)(i) x = (3)(ii) Solve by factorising x 2 – 7x + 6 = 0.Answer(a)(ii) x = ................. or x = .. (3)(iii) Solve5x 32- + 102x + = 4. Answer(a)(iii) x = (4)ForExaminer ′s Use(b) 12 = 112 + 22 = 5 12 + 22 + 32 = 1412 + 22 + 32 + 42 = 3012 + 22 + 32 + 42 + ..................... + n 2 = an 3 + bn 2 + 6nWork out the values of a and b .Answer(b) a = ...............................................b = ............................................... [6]_____________________________________________________________________________________BLANK PAGEPermission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the publisher will be pleased to make amends at the earliest possible opportunity.University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.。

igcse考试

igcse考试IGCSE（International General Certificate of Secondary Education）是国外14岁至16岁全世界考试最多人数的体系之一，是CIE(Cambridge International examination), 剑桥全球测试的一部分。

其证书，只要是说英文的国家地区均会得到承认，该考试相当于我们理解的"SSAT"，唯一不同的是:若同学想申请英国名校剑桥，牛津大学等相近英系大学，此考试成绩是申请的重要参考之一。

因中英教育体系的不同，高中的GPA成绩换算，英国无标准，不能准确了解学员的智力和学术能力，所以该考试成绩很有必要。

定义中国鲜有人知道IGCSE，大部分人知道的是SAT，因为SAT是进美国大学必不可少的。

但是想进英系大学，如剑桥，牛津大学的人应关心一下。

在IGCSE里，有64个可选科目，你可以在有限度的情况下自由选择，限度是:英文和数学必修，但英文和数学各有3个不同的选择。

IGCSE 至始至终都是要培养学生的创新能力和爱好，所以有64 个科目可选。

两年之后，你会去接受剑桥教授出的考卷，其中一个paper是一个小时，很简单;另一个paper是2个半小时，非常难写完。

之后考卷被送往剑桥去改。

1~3个月之后你会收到他们给你的证书。

证书上有几个不同的级别(以百分比来算)A star: 90%以上A:70%~89%B:60%~69%C:50%~59%D:42%~49%E:35%~41%F:25%~34%G:10%~24%U:小于10%这只是一个参考值,实际情况要看当年全球考生的成绩而定,实际值和此数据相差不会很大.GCSE的终级目标是给AS，A一个很好的奠基，之后去读AS和A，用AS和A 的成绩去大学。

AS和A的程序和IGCSE基本相同，但难度不同。

主要课程AccountingAfrikaans - First LanguageAfrikaans - Second LanguageAgricultureArabic - First LanguageArabic - Foreign LanguageArt and DesignBangladesh StudiesBiologyBusiness StudiesChemistryChild DevelopmentChinese (Mandarin) - Foreign LanguageChinese - First LanguageComputer StudiesCzech - First LanguageDesign and TechnologyDevelopment StudiesDramaDutch - First LanguageDutch - Foreign LanguageEconomicsEnglish - First LanguageEnglish - LiteratureEnglish - Second LanguageEnvironmental ManagementFood and NutritionFrench - First LanguageFrench - Foreign LanguageGeographyGerman - First LanguageGerman - Foreign LanguageGlobal PerspectivesGreek - Foreign LanguageHindi as a Second LanguageHistoryIndonesian - Foreign Language Information and Communication Technology Information TechnologyIsiZulu as a Second LanguageJapanese - First LanguageJapanese - Foreign LanguageKorean (First Language)LatinMalay - Foreign LanguageMathematicsMathematics (with coursework) Mathematics - AdditionalCambridge International Mathematics MusicPakistan StudiesPhysical EducationPhysical SciencePhysicsPortuguese - First LanguagePortuguese - Foreign Language Religious StudiesRussian - First LanguageScience - CombinedSciences - Co-ordinated (Double) SociologySpanish - First LanguageSpanish - Foreign Language Spanish - LiteratureThai - First LanguageTravel and TourismTurkish - First LanguageTwenty-First Century Science (GOOGLE语言工具直接翻译。

2013年第九届“IMC国际数学竞赛”(六年级)初赛详解

六年级 (初赛) 试题解答姓名_____________ 学校_____________ 得分____________一、填空题I （每小题6分，共60分） 1. 计算：4137525152044126154+---=_________；答案：59解：原式=221211111135454119141114-++-+-+--=2139-=59．2. 计算：1211211211213⨯+⨯+⨯+⨯+=_______；答案：解：512133⨯+=，3112155⨯+=，521211111⨯+=，4311121=2212121⨯+=．3. 一个六位数，其数字只能是2或3，且没有两个3是相邻的．那么这样的六位数有________个；答案：21解：6个2，0个3组成共有07C 种，5个2，1个3组成共有16C 种，4个2，2个3组成共有25C 种，3个2，3个3组成共有34C 种，共计07C +16C +25C +34C =21种．4. 一个半径为4的扇形，当π取3时，这个扇形的周长与面积数值相等，那么这个扇形的圆心角的度数为_________；答案：120解：设圆心角为n ︒，则2343424180360n n ⨯⨯⨯⨯⨯+=，n =120．5. 若六位数abcabc 恰有18个约数，那么abcabc =__________；答案：143143解：71113abcabc abc =⨯⨯⨯，若有18个因数，必须是2271113143143⨯⨯=．6. 8和24是两个有趣的数，它们的乘积恰好是这两个数之和的6倍．那么满足此条件的不同的两个正整数还有________组；（（8，24）与（24，8）视为同一组）答案：3解：设这两个数为a 、b ，ab =6(a +b )，1116a b=+，742a b =⎧⎨=⎩或918a b =⎧⎨=⎩或1015a b =⎧⎨=⎩，共3组．7. 用4个相同的红球、4个相同的蓝球、4个相同的黄球摆放成右图的三角形的形状，要求相邻两球的颜色不同．那么共有________种不同的放法；(右图旋转、翻转相同的算作不同情况)答案：6解：从中间三个球入手，共6种放法，其他球的位置固定，所以共有6种放法．8. 由4个不同的数字组成的四位数abcd ，交换ab 与cd 的顺序得到四位数cdab ，两者的差能被2013整除，那么原来的四位数最大为________；答案：9837解：2013()abcd cdab -，603999()ab cd -，61()ab cd -，ab 最大为98，那么cd =98-61=37，所以abcd =9837．9. 若干人共同出钱购买玩具，后来有10人决定不参加，这样余下的人就得每人多出6元；临到付款时又有10人退出，于是最后余下的人又多出9元；那么原先同意购玩具的有________人；答案：60解：设原来有x 人，每人y 元，则xy =(x -10)(y +6)=(x -20)(y +15)，解得x =60，y =30，所以原来同意买玩具的有60人．10. 一次暴雨，导致某立交桥下积水，水以固定的速度涌入．市政部门预计：若派23辆抽水车需要9小时抽完，若派27辆抽水车则需6小时抽完，由于配给不足，先派去若干辆抽水车，工作了4小时之后，又增派来9辆抽水车，一起工作8小时恰好抽完．那么原来现场有__________辆抽水车；答案：15解：1）每小时涌入(23⨯9-27⨯6)÷(9-6)=15份水；2）开始抽水前有水27⨯6-15⨯6=72份；3）原有抽水机(72+12⨯15-8⨯9)÷12=15台．二、填空题II （每小题8分，共40分）11. 某容器中装有盐水．老师让小明再倒入30％的盐水300克，以配成20％的盐水．但小明却错误地倒入了300克水．老师发现后说，不要紧，你再将30%的盐水a 克倒入容器，就可以得到20％的盐水了．那么a =__________；答案：900解：原来需要30%的盐水300克，再加上现在把300克的水与30%的盐水混合成20%的盐水时需要的30%的盐水，12. 一条河流在A 港口有两个分岔口，其中有一条水流向B 港口，另一条水流向C 港口，在B 、C 之间开通一条运河，没有水流动，且任意两个港口之间的距离相等．现在有甲、乙两条船，同时从B 出发沿不同的水路航行，结果在AC 之间距离A 港800米处相遇，又知两船在静水中的速度都为水速的3倍，那么三个港口之间的水路总长为__________米；答案：5400解：4:3:2V V V ===顺静逆，设两个港口之间的距离为12份，B 到C 的时间为4，B 到A 的时间为6，当经过6份时间时，另一条船在离开C 的距离为2⨯2=4，接下来相遇点距离A (12-4)÷(4+2)⨯4=163份，所以三个港口的水路总长为168001233÷⨯⨯=5400米．13. 如图，在面积为40的长方形ABCD 中，E 、F 、G 分别是边AB 、BC 、CD 的中点，那么四边形MFNP 的面积为__________；答案：9解：如图1，△ADF 的面积为20，使用沙漏模型可以得到23AM M F=，同理23D N N F=，如图2，使用燕尾定理得到四边形MFNP 的面积为920920⨯=．14. 把0~9这十个数字各一次填入下面的等式中，使得等式成立：()()()+++2013⨯⨯= 答案：(1+2)⨯(3+8)⨯(640-579)=2013解：1）设()()()2013a b c d ef g hij +⨯+⨯+=，又因为2013=3⨯11⨯61，所以三个因数分别为3、11和61．2）不妨a 与b 一奇一偶，和为3，c 与d 一奇一偶，和为11，又知e -h =1，也是一奇一偶，g 与j 的也是1或9，也是一奇一偶，那么f 与i 也是一奇一偶．3）当g -j =1时，那么10+f -i =6，这与f 与i 也是一奇一偶矛盾．4）当10+g -j =1时，那么那么g =0，.j =9，从而a +b =1+2，接下来从3、4、5、6、7、8中找到一组差1，一组差3的数，一组合为11的数，可以得到3+8=11、6-5=1、7-4=3，所以得到(1+2)⨯(3+8)⨯(640-579)=2013．图1A E DBC F MHACF M2 332 图2A E PD G B CFM N15.右图是一个跳棋盘，现在已经放满了跳棋，需要取走__________个球，才能保证剩下的球中没有连线的五子连珠（5个相邻棋子在一条直线上称作五子连珠）。

(完整word)2013NOIP初赛提高组试题解析

19.2 十九届提高组一、单项选择题（共15题，每题1.5分，共计22.5分；每题有且仅有一个正确选项）1．一个32位整型变量占用（ A ）个字节。

A．4 B．8 C．32 D．1282．二进制数11.01在十进制下是（ A ）。

A．3.25 B．4.125 C．6.25 D．11.1253．下面的故事与（ B ）算法有着异曲同工之妙。

从前有座山，山里有座庙，庙里有个老和尚在给小和尚讲故事：“从前有座山，山里有座庙，庙里有个老和尚在给小和尚讲故事：‘从前有座山，山里有座庙，庙里有个老和尚在给小和尚讲故事…………………………’”A．枚举B．递归C．贪心D．分治4．1948年，（ D ）将热力学中的熵引入信息通信领域，标志着信息论研究的开端。

A．冯•诺伊曼(John von Neumann) B．图灵（Alan Turing）C．欧拉（Leonhard Euler） D．克劳德•香农（Claude Shannon）【分析】香农信息论鼻祖5．已知一棵二叉树有2013个节点，则其中至多有（ A ）个节点有2个子节点。

A．1006 B．1007 C．1023 D．1024【分析】（1）树根深度为0，深度为10的满二叉树节点总数2047；（2）本题树深为10的完全二叉树，与满二叉树相比少了34个节点，（3）深度为9的满二叉树节点总数量为1023；（4）1023-（34/2）=10066．在一个有向图中，如果任意两点之间都存在路径相连，则称其为连通图。

右图是一个有5个顶点、8条边的连通图。

若要使它不再是连通图，至少要删去其中的（ B ）条边。

A．2 B．3 C．4 D．5【分析】要使图不联通，只要其中某一个节点不连通即可，所有顶点度最少是3，所以最少需要删除3条边7．斐波那契数列的定义如下：F1=1，F2=1，F n=F n-1+F n-2（n≥3）。

如果用下面的函数计算斐波那契数列的第n项，则其时间复杂度为（ D ）。