初中选择易错100题

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中考历史易错选择题100道

中考历史易错选择题100道

初中历史易错选择题汇总1.忽视题干所给时间(时期)限制,匆忙答题。

例题:我国“一五”计划期间生产关系的变化,大致相当于苏联的()A.1918—1921年B.1921—1927年C.1928—1936年D.1937—1941年解析:我国“一五”计划期间生产关系上的变化指“一化三改”,变生产资料私有制为生产资料公有制。

对照苏联完成此项任务应是1928年至1937年,故正确选项C。

例题:新中国成立时面临的国际问题是()A..二战处于反攻阶段B.美苏处于“冷战”之中C.世界两大军事集团对峙局面形成D.美苏争霸愈演愈烈此题要审出时间“新中国成立”,再现新中国成立时间1949年。

可排除A 项,C、D项皆是发生在20世纪50中期以后的历史事件,故正确答案为B 项。

因美苏处于“冷战”开始于1947年,结束于1991年。

2.历史概念的理解不透彻,不能把握本质内涵较难的选择题,命题者往往在历史事件及历史概念的内涵、外延和时代特征上做文章。

内涵是指一个概念所反映事物的本质属性的总和,也就是概念的内容。

外延在逻辑学上指一个概念所确指的对象的范围。

这类选择题,考试中经常见到。

我们唯有在理解的基础上加强记忆,在记忆的基础上进一步理解,把课本中重要概念、关键字词真正弄懂吃透,才不至于面对扑朔迷离的选项感到茫然。

例题:唐朝的三省六部制进一步完善了专制主义中央集权制度,其完善的含义是()A、中央机构设置的增加B、使地方权力进一步分散C、使皇权进一步加强D、使中央各部门权利得以相互制约此题多数学生选C项加强皇权,表现出学生对专制主义中央集权制度的发展脉络及影响认识不清。

此制度自秦朝建立到唐朝完善是适应封建的生产关系具有积极意义。

唐朝的三省六部制是在秦朝三公九卿制度基础上的发展,使中央机构更加完善,完善指的是各部门之间可以相互制约同时提高了办事效率。

正确选项为D.3.历史基本史实掌握不牢固例题:虽然身躯伟岸是“理想领袖”形象的一个组成部分,但现实生活却要复杂得多。

初中英语九年级英语语法易错难点题 100题选择题附答案

初中英语九年级英语语法易错难点题 100题选择题附答案

初中英语单选题100道易错题合集,测测你的正确率吧!( )1. —Do you know what he did all day?—He spent as much time playing as he ______.A. studyingB. was studyingC. studiedD. did studying( )2. I can’t say ______I want to see him again. We haven’t seen each other for a long time.A. how longB. how soonC. how oftenD. how much( )3. It is said that land animals ______ from sea animals.A. were developedB. developedC. are developingD. develops ( )4. —Would you like some coffee?—Yes, and please get me some milk, too. I prefer coffee ______milk.A. toB. withC. thanD. of( )5. ______ made his teacher unhappy.A. Tom came lateB. Tom’s came lateC. Tom’s l ateD. Tom’s coming late ( )6. Father asked Edison ________.A. what was he doing that forB. why he was doing that forC. how he was doing that forD. what he was doing that for( )7. We are going to have the sports meeting _____it _______tomorrow.A. if, rainsB. unless, will rainC. unless, rainsD. when, will rain ( )8. ______ of the students in our class _______ from the country.A. Three fifth, isB. Three fifths, areC. Third fives, areD. Three five, is ( )9. News can _____every corner of the world with the help of the Internet.A. reachB. arriveC. getD. reach to( )10. Here is only one seat for the old man________.A. to sitB. sittingC. sitting onD. to sit on( )11. Though this pair of shoes is a bit expensive, I would like to________.A. try them onB. try on themC. try them outD. try out them( )12. How can we finish ____ much work in ___a short time?A. so, soB. such, suchC. so, suchD. such, so( )13. Last night, he had his car________.A. to stealB. stoleC. stealingD. stolen( )14. Last night several young men ________the bank of lots of money.A. stoleB. robbedC. tookD. got( )15. Where was this big egg_____?A. liedB. lainC. laidD. lay( )16. _______ school, we can get much knowledge.A. BecauseB. Thanks forC. Thanks withD. Thanks to( )17. You’d better think about ________ a car now.A. whether buyB. if buyC. whether to buyD. if to buy( )18. He talks too much as if he ______everything.A. knowsB. knewC. has knownD. to know( )19. He will come to stay with us for _________________ next month.A. some time sometimeB. sometime some timeC. sometimeD. some times ( )20. This radio program is well worth________.A. listeningB. listening toC. watchingD. to listen( )21. He must be a doctor, _________?A. mustn’t heB. must heC. is heD. isn’t he( )22. This building is taller than _________one around it.A. any otherB. another oneC. anyD. some other( )23. Though he live_____, he doesn’t feel ____ because he can enjoy himself at home.A. lonely, lonelyB. alone, aloneC. alone, lonelyD. lonely, alone ( )24. Yangzhou High School sounds _______ a good one. But I would like to have more information about it.A. /B. asC. likeD. what( )25. —How long_______ you _______ the English dictionary? —About half a year.A. have, go tB. did, buyC. have, hadD. have, bought( )26. _______ my great surprise, such a little boy can draw so many beautiful pictures.A. InB. WithC. ToD. For( )27. _____the old man spoke, ____he became.A. The more, the angryB. The more, the more angrilyC. The more, the angrierD. The most ,the angrier( )28. ____the help of my English teacher, I did well in English last term.A. UnderB. InC. WithD. For( )29. She _____a teacher, but now she is a doctor.A. used beB. used to beC. was used to beD. was( )30. What do you think __________him change his mind?A. to makeB. madeC. makeD. making( )31. They are practising _______in the hall.A. danceB. to danceC. dancingD. to dancing( )32. It is _____that we all like to read it.A. so good a book.B. such good a bookC. so a good bookD. such good books ( )33. She often offers _______.A. us with some foodB. some food to usC. us to some foodD. money me ( )34. Most sharks feed _____ fish and other animals.A. withB. forC. onD. by( )35. —Can you look after my daughter for me while I am away? —______.A. It’s a pleasureB. With pleasureC. Not at allD. You’re welcome ( )36. Can you think of a way ________ it?A. doingB. doC. to doD. of do( )37. I’ll get her _______harder. You wa it and see.A. studyB. to studyC. studiedD. studies( )38. Hearing his mother’s voice, the child couldn’t wait _______out.A. rushingB. to rushC. rushedD. for rushing( )39. The king _______himself from a leaning tree.A. hungB. hangedC. hungedD. hang( )40. Jim got up early _______ he caught the early train.A. becauseB. orC. so thatD. until( )41. When _______the PRC______, do you know?A. did, findB. did, foundC. was, foundD. was, founded( )42. What’s six _________ seven?A. multipliesB. multiplyingC. multipliedD. multiplied by( )43. My watch has stopped. It seems that I’ll go and _____ this afternoon.A. have someone repaired itB. have someone to repair itC. have someone repair itD. have it repair( )44. I’m sure that their team will ______ ours.A. failB. takeC. winD. beat( )45. The flight was put off ________ fog.A. becauseB. as the resultC. as a result ofD. as( )46. He watched the game with a ______look.A. surprisingB. surprisedC. surpriseD. surprises( )47. _____the time he got up, the road had already be covered with think snow.A. ForB. ByC. AtD. Until( )48. It’s very ________ to talk with him.A. worthB. rewardingC. deserveD. pleasure( )49. To help animals is _______humans themselves.A. helpB. helpingC. helpfulD. to helping( )50. Have you seen the pen ______I have lost?A. whatB. thatC. whoD. whose( )51. The boy was too _______ to move when the train came near.A. afraidB. frighteningC. frightenedD. frighten( )52. Water must be kept _______away.A. to runB. runsC. runningD. from running( )53. He is the ______of his parents. They are very _______of him.A. proud, prideB. pride, proudC. pride, prideD. proud, proud ( )54. Mum, my shoes are______. Can I have a new pair?A. wearing outB. wornC. worn outD. broken out( )55. _______! You have a lot of time to go.A. Don’t rushB. Don’t rush outC. Don’t lookD. Don’t go( )56. He had lived in this city _______I moved here. But I hear that he will leave this city_______.A. long before, before longB. before long, before longC. long before, long beforeD. before long, long before( )57. It’s __________late now ,but I still have ___________homework to do.A. too much, too muchB. much too, much tooC. too much, much tooD. much too, too much( )58. He has great ________ in collecting stamps.A. interestingB. interestedC. interestD. to interest( )59. We should make a contribution to _______the environment.A. improveB. improvingC. changeD. changing( )60. —May I _____your motorbike, please?—Certainly. But you mustn’t _____ it to others.A. lend, lendB. borrow, lendC. borrow, borrowD. lend, borrow ( )61. The captains of the two sides will _______the conversation later.A. go onB. carry onC. keep onD. go with( )62. Will you please make ________ for me? I must be together with my baby.A. a roomB. roomC. a spaceD. rooms( )63. The machine must be ________at once.A. put offB. put onC. put awayD. put right( )64. I wonder _______ the rain will stop soon.A. thatB. / C .if D. what( )65. I will help you if I _______.A. am ableB. will be ableC. can be able toD. am able to( )66. I think _______impossible to learn English well in a short time.A. thatB. thisC. itD. /( )67. No matter______, you should not give it up.A. what will happenB. what is happenedC. what happensD. happen what ( )68. There is nothing _______with you. You needn’t be worried.A. the wrongB. matterC. the matterD. the problem( )69. Older people should __________politely.A. speak toB. be spokenC. be spoken toD. spoken to( )70. You should have a try _______you don’t know how to do it.A. thoughB. even thoughC. as thoughD. even( )71. When do you think________?A. will he be backB. he will be backC. will be he backD. he will back ( )72. We usually see the sign “This Side Up”_______.A. in a roomB. on the roadC. on a boxD. on a glass( )73. I will ___ until your father comes back home. I have something important to talk with him.A. not waitB. leaveC. waitD. not to wait( )74. — This boy is very clever. —_________.A. So is heB. So he isC. He is soD. He so is( )75. It’s not an easy thing to give up _________ at my age.A. smokeB. to smokeC. smokingD. to smoking( )76. Hainan Island is the place _____, whether it is summer or winter.A. to goB. to travelC. to beD. to visit to( )77. He is afraid _______the bridge because he is afraid _______ into the water.A. to cross, of fallingB. of crossing, to fallC. to cross, to fallD. of crossing, of falling( )78. He has lived and worked in China _______1996.A. inB. sinceC. forD. by( )79. It’s great fun _______ the yo-yo. Do you want a go?A. playingB. to playC. play withD. playing with( )80. I really don’t know what ________next. Can you help me?A. to doB. to do itC. doD. do it( )81. Someone has called the police, ________?A. has heB. hasn’t sheC. ha sn’t theyD. haven’t they( )82. You’d better go to bed early on weekdays, _______ you?A. hadn’tB. didn’tC. weren’tD. needn’t( )83. My parents went to work, leaving me _______ the homework at home alone.A. to doB. didC. for doingD. doing( )84. Your pen writes_______. Where did you buy it?A. goodB. niceC. neatD. well( )85. She is _______ girl that I have ever known.A. goodB. betterC. the bestD. best( )86. We lived a hard life _______.A. in the 1960sB. in 1960sC. in the 1960D. in 1960s’( )87. English is spoken ______the world.A. all overB. byC. asD. for( )88. All the students _______when they heard the good news.A. were cheeredB. cheeredC. are cheeredD. cheering( )89. Modem can be used for connecting a computer ______ a phone line.A. withB. forC. toD. towards( )90. _______ the population by the year 2050?A. How many will beB. How much will beC. What will beD. What will ( )91. Your ticket must _______ ahead of time.A. bookB. be bookedC. orderD. be ordered( )92. You must_______ try _______make mistakes any more.A. not, toB. /, not toC. /, don’tD. /, to( )93. Don’t _______the seas any more, or the living things in them will die.A. litterB. litter intoC. litter toD. litter in( )94. In the first half, we scored three_______.A. ballsB. footballsC. goalsD. games( )95. Last year the boss of a large factory _______two million yuan to our school.A. gave inB. gave upC. gave backD. gave away( )96. I saw him _______ your room when I walked past yesterday afternoon.A. entering intoB. to enterC. enterD. enter into( )97. I’d like something _______ English. Could you make some for me?A. realB. reallyC. trueD. truly( )98. The teacher said that light _______faster than sound.A. travelledB. is travellingC. travelsD. to travel( )99. To complain too often ______a good thing.A. it isn’tB. that isn’tC. isn’tD. isn’t it( )100. There are many _______ people working for the Great Green Wall.A. millionB. million ofC. millions ofD. millions【答案】01-10 DDBBD DCBAD11-20 ACDBC DCBAB21-30 DCCCC CCCBB31-40 CABCB CBBBC41-50 DDCDC BBBBB51-60 CDBCA ADCBB61-70 BBDCD CCCCB71-80 BCCBC CABDA81-90 DADDC AABCC91-100 BBACD CBCCC【解析】1.D。

初中生物考试易错选择题(人教版七下部分)

初中生物考试易错选择题(人教版七下部分)

初中生物考试易错选择题(人教版七下部分)1.下面关于胎盘的说法不正确的是:( ) [单选题] *A.胎盘里部分血管是胎儿的B.胎盘里胎儿的血管和母体的血管是相通的(正确答案)C.胎盘内的绒毛间充满母体的血液D.胎盘是胎儿和母体交换物质的器官2.做过双侧输卵管结扎手术的育龄妇女,一般将不再具有生育能力,分析其原因不正确的是:() [单选题] *A.卵巢能正常排出卵细胞B.卵巢能正常分泌雌性激素C.卵细胞不能在输卵管与精子相遇D.胚泡无法植入子宫内膜(正确答案)3.小李经常偏食,结果他的上皮组织发生了角质化,皮肤干燥,且还出现皮下血管出血,这是由于他偏食造成体内缺乏:() [单选题] *A.维生素A和维生素DB.维生素A和维生素C(正确答案)C.维生素C和维生素DD.维生素A 和维生素D4.消化道中消化淀粉的消化液是由哪些腺体分泌的? ()①唾液腺②胃腺③肝脏④肠腺⑤胰腺 [单选题] *A.②④⑤B.①④⑤(正确答案)C.③④⑤D.①③⑤5.下列有关对人体消化系统的描述中,不正确的是() [单选题] *A. 所有的消化液都含有消化酶(正确答案)B. 所有的消化腺都能分泌消化液C. 消化系统由消化道和消化腺两部分组成D. 小肠是消化和吸收的主要部位6.人体呼吸道具有净化空气的作用。

下列能使吸入的气体变清洁的结构有( )①鼻毛②声带③气管的内表面覆盖着有纤毛的黏膜④鼻黏膜⑤会厌软骨 [单选题] *A、①②⑤B、①③④(正确答案)C、②③④D、③④⑤7.煤气中毒是由于人体吸入了较多的:() [单选题] *A.氧气B.一氧化碳(正确答案)C.二氧化碳D.氮气8.人的肺泡数量很多,外缠绕着毛细血管网,肺泡壁和毛细血管壁都很薄,以下说法不正确的是: () [单选题] *A.增加血液与肺泡进行气体交换的面积B.便于血液与肺泡的气体交换C.氧气由肺泡进入血液只需穿过两层细胞D.便于组织细胞与血液的物质交换(正确答案)9.“唾液对淀粉的消化实验”要求在一定温度进行,这是由于唾液中的淀粉酶在高于和低于37℃条件下催化作用都会逐渐降低。

人教版初中英语七年级上册 专题一 单项选择100道(知识全覆盖重点知识+难点易错点)

人教版初中英语七年级上册  专题一 单项选择100道(知识全覆盖重点知识+难点易错点)
5.冠词使用切勿混
________ green jacket is a birthday gift from my mother.
A.AB.AnC.TheD./
【答案】C
【详解】
句意:这件绿色的夹克是我妈妈送给我的生日礼物。
考查冠词辨析。根据“green jacket is a birthday gift from my mother”可知,此处特指妈妈送的那件绿色的夹克,用定冠词the表特指,故选C。
A.Ken and Bob'sB.Ken's and Bob's
C.Ken's and BobD.Ken and Bob
19.After ______ class I have gymnastics (体操训练) ______ two hours.
A.the; forB.the; atC./; forD./; at
25.My grandma's birthday is ________ March and it's ________ March 16th.
A.in;inB.in;onC.on;onD.on;in
26.—Do you see Cindy and Mike in the school library?
【答案】C
【详解】
句意:每天吃蔬菜对我们的健康有好处。
考查形容词短语辨析。is bad for对……有害处;is bad with不搭配;is good for对……有好处;is good with与……相处得好。根据常识可知,每天吃蔬菜对我们的健康有好处。故选C。
2.名词单复数变形要记牢
—What’s in the ________?

中考英语精选单选题易错题100题

中考英语精选单选题易错题100题

中考英语精选单选题易错题100题中考英语精选单选题易错题100题1、What do you think ______solve the problem ?A、you can doB、can you doC、you can do toD、can you do to2、In the past he often made his sister____, but now he is often made ___by his sister.A、to cry; to cryB、cry; cryC、to cry; cryD、cry; to cry3、The teacher told us that the sun ____in the east.A、risesB、roseC、raisesD、raised4、He lives in a village _____there are a lot of trees.A、thereB、whereC、thatD、which5、He _________ Alice for ten years.A 、married to B、has married toC、has marriedD、has been married to6、We need fifteen more people _____our team to do the job.A、butB、exceptC、as wellD、besides7、The y won’t allow us ________ at this beach.A、swimming8 、Is this factory ______you visited last week?A、thatB、whereC、the oneD、in which9、The reason ____he was absent from the meeting was ____his car broke down on the way.A、that; becauseB、why; thatC、that; thatD、for; that10、Is the river_____ through that town very large?A、which flowsB、flowsC、that flowingD、whose flows11、The teacher told me that the students I wanted to see were seen___ football on the playground just now.A、playingB、to be playingC、playD、to play12、The red rose is the only one _____I real like.A、whichB、whoC、thatD、whom13、All the apples _____ fell down were eaten by the pigs.A、thoseB、whichC、whatD、that14、Don’t forget the day ______you were received into the Youth League.A、when15、I prefer________ at home to ______outside.A、staying, playingB、to stay, playC、staying, playD、to stay, playing16、The box is _____what I saw in the shop.A、same asB、the same likeC、the same thatD、the same as17、The pen _______she writes letters is broken.A、whichB、thatC、with whichD、by which18、Would you like to ______us in our discussion.A、take part inB、joinC、taking part inD、joining19、I’m sure the red team will ______the game .A、winB、beatC、defeatD、succeed20、Ahead of me I saw a woman ____I thought was my aunt.A、whoB、whomC、of whomD、whose21、_____your help, everything in the room is in good order now.A、SinceD、Thanks to22、He is known to the world and has a lot of friends_______A、in and out of abroadB、at home and abroadC、at home and at abroadD、in home and out of abroad23、---Are you going there with them ?----If you go,__________.A、I also goB、so do IC、so I willD、so will I24、-----The flower is beautiful.---____________A、So is itB、So it isC、It is soD、So it is25、The number of people invited ____fifty, but a number of them _____absent for different reasons.A、were; wasB、was ; wasC、was; wereD、were; were26、We haven’t had any success _______A、before longB、so longC、by farD、so far27、Travellers ____our country enjoy the beautiful sights in Beijing, Hangzhou and many other places of interest.A、forB、to28、If a man ______succeed, he must work as hard as he can.A、willB、shouldC、is going toD、is to29、----I am sorry I didn’t do a good job.-----Never mind. ______ you have tried your best.A、Above allB、In allC、At allD、After all30、The best way to make sure that you can keep fit is to ____healthy eating habits.A、findB、createC、developD、prepare31、We have spent _____money on English books .A、a great deal ofB、a good manyC、a plenty ofD、a number of32、_______met, it won’t be easily forgotten.A、If onlyB、When ifC、OnceD、Once you were33、The differences_____ these two pictures _____ colour are easy to see.A、in, ofB、from, ofC、between ,inD、of ,in34、You should put_____ “s” at the end of this word.A、a35、----What’s ______population of China ?----China has_____ population of 1.2 billion.A、a; theB、the; aC、/;/D、the; the36、It`s _______here. We can’t work long hours here.A、very much coldB、much coldC、much too coldD、too much cold37、_______terrible weather we’ve been having these days!A、How aB、What aC、HowD、What38、----Have you decided when_____?-----Yes, tomorrow morning.A、will you leaveB、to be leavingC、are you leavingD、to leave39、The song ____My heart will go on is liked by the young people.A、callB、callingC、calledD、to call40、Train services are now back to ______after three days of typhoon.A、usualB、commonC、ordinaryD、normalC、forD、to42、The policeman caught hold of the thief and hit him ____the head.A、in theB、on hisC、on theD、in his43、Did John hit Bob _____eye ?A、in theB、on theC、in hisD、on his44、There is ____ interesting ____ today’s newspaper.A、anything …inB、nothing. .inC、something. .onD、nothing.. on45、Has your teacher given you any advice______ your study?A、inB、toC、onD、with46、It’s bad manners to laugh _____ oth ers when they are _____ trouble.A、at ,inB、over ,atC、with ,onD、to, with47、Betty doesn’t have enough money to buy that coat. It’s very ___. The price is too_____.A、high, highB、expensive, expensiveC、expensive, highA、wearingB、wearC、wearsD、is worn49、The diamond is _________.A、very valuableB、of great valueC、great valueD、A or B50、Behind the dancer there was a woman _______a large diamond ring.A、carryingB、dressingC、wearingD、having51、The young teacher who has a ____face can make his classes ____and interesting.A、lovely, livelyB、lovely, lovelyC、likely, friendlyD、ugly, lively52、They were still _____their friends after their child’s long illness.A、in debt toB、in the debt toC、in debt withD、in the debt with53、_______, my brother passed the exam.A、To my great joyB、To my great surprisedC、With my joyD、With my surprise54、I am all tears, ____,I am listening to you with all attention.A、in another wordsB、in the other wordsC、with other wordsC、so as toD、in order to56、As you know, whether the person will be elected president is matter of ___interest.A、generalB、commonC、ordinaryD、mostly57、I _______ by his story that he made up.A、was taken onB、was taken outC、was taken inD、am taken in58、He didn’t go into detail on the subject ,he spoke ______.A、in generalB、in particularC、in commonD、in short559、We designed the machine _____the purpose _______production.A、for, of increasingB、with, of increasingC、for, to increaseD、A or B60、Hospital doctors don’t go out very often as their work ____all their time.A、takes awayB、takes inC、takes overD、takes up61、We offered him our congratulation ____his passing the entrance exam.A、onB、forC、withC、is interested in; intoD、interests; enjoy63、We each _____ strong points and each of us on the other hand _____weak points.A、have, haveB、has, haveC、has, hasD、have, has64、He is one of the students who, I am sure, always do ____ best.A、hisB、one’sC、myD、their65、The police ____determined to bring back the missing boy when his family____almost given hope.A、is, hasB、are, haveC、are, hasD、is, have66、More than one girl ____ late for class this morning.A 、are B、is C、was D、were67、Many a student _____ in the exam.A、have failedB、had been failedC、has failedD、will be failed68、What he says and what he does _______.A、is not agreeB、are not agreeC、does not agreeD、do not agree69、Not only politics but also English is important. In other words , ___is important.A、English, as well as politicsD、politics, as well as English70、It was at the very beginning____ Mr.Smith made a decision ___we should send for a doctor.A、what, thatB、that, whichC、which, thatD、that, that71、On the way back home from the ball, she suddenly found her necklace____.A、missedB、losingC、goneD、be stolen72、He didn’t go to the party not ______the time but _____he was ill.A、because of, becauseB、because, becauseC、because, because ofD、because of, because of73、The teacher gave me a piece of paper________.A、to write onB、to be written onC、to write inD、to be written74、I can’t believe he could jump _____high.A、very muchB、suchC、thatD、this75、-----The boys are not doing a good job at all, are they?------_____________.A、I guess not soB、I don’t guess soC、I don’t guessD、I guess not76、The magazine is ______reading, so he advised me ____it.A、well worth; to buyC、worthing , buyingD、worthy, to buy77、She is on a special _____to lose _____weight.A、food; herB、food;/C、diet; herD、diet;/78、Jenny_____ a rich man. She has____ him for 5 years.A、married with; married withB、married; marriedC、married to; been marriedD、married; been married to79、I am _____hungry. Give me _______of milk.A、a bit; a littleB、not a little; a bitC、little; a litD、not a little; a little80 、A good friend is someone _____makes you ______.A 、which; happy B、who; happilyC、who; happyD、whose; happily81、He was about ____when suddenly the telephone rang.A、to leave B 、to starting C、leaving D、setting off82、This task is _____difficult for us. We need ______people.A、much too; another threeB、too much; other threeC、much too; more threeD、too much; three more83、He seems to ______to Jane. He knows her well.A、have been introducedB、be introducedC、have introducedD、introduced84、This is a film ______Spielberg used real actors instead of stunt men.85、He ____- much of his success and happiness _____his wife and children.A、thanks; toB、owes; toC、owns; toD、thinks; highly of86、He will never forget the days ______he spent with you in Japan.A、whenB、thatC、on whichD、in which87、Which sentence is incorrect ?A、I feel interested in classical musicB、I take interest in classical musicC、I am not into classical musicD、I don’t fond of classical music88、No one likes _______in _____public.A、to be laughed at; theB、laughing at; theC、being laughed at; /D、to be laughing at; /89、We are considering _______a sports meet next month.A、to holdB、holdingC、to be heldD、as holding90、Which sentence is incorrect?A、He devoted himself to the work of children’s health care.B、He is devoted to his work.C、He devoted all his life to work hard in people’s interests.D、He is determined to make more money for his family.91、He doesn’t like classical music and_______ I .92、Friends should ______happiness and sorrow _____each other.A、share, withB、solve, withC、share, fromD、share, to93、---I missed the first part of the film .It was really a pity.----You ________home half an hour earlier.A、should have leftB、must have leftC、should leaveD、must leave94、The storm died away at last with the golden waves ____the shore in peace.A、beatenB、beatC、to beatD、beating95、The whites are ___holiday ,but I don’t know where they have gone __their holidays.A、in ,forB、on ,forC、for, inD、at, on96、The river ____are covered with trees is very long.A、which banksB、of which banksC、whose the banksD、the banks of which97、She likes to use words ______clear to her.A 、of which the meaning B、of which meaningC 、whose of meaning D、meaning of which98、The price of this washing machine has been increased ____15%.A、upC、byD、from99、_____someone’s health, you raise y our glass.A、Drink toB、To drink toC、If you drinkD、If drink to100、Please ______me about the interview____ I forget.A、remind; in caseB、remember; in caseC、remember, in case ofD、remind of; in case of参考答案1-5 CDABD6-10 DBCBA11-15 ACDAA16-20 DCBAA21-25 DBDBC26-30 DBDDC31-35 ACCCB36-40 CDDCD41-45 BCABC46-50 ACCDC51-55 AAADA56-60 ACADD61-65 ACDDB66-70 CCDBD71-75 CAACD76-80 ADDBC81-85 AAACB86-90 BDCBC91-95 BAADB96-100 DACBA。

初三中考化学易错选择题专项训练

初三中考化学易错选择题专项训练

初三化学易错选择题专项训练1.许多同学喜欢吃烧烤食物,烧烤常用木炭作燃料;下列叙述中,正确的是A在室内烧烤时要注意通风 B烧烤有时看到的黄色火焰是木炭燃烧产生的C烧烤时扇炭火是为了降温 D用含硫的焦炭代替木炭不会影响人体健康2.下列对酒精灯和酒精的认识中,错误的是A用火柴点燃酒精灯——使温度达到酒精的着火点B用酒精灯加热物质——酒精燃烧能放出大量的热C用灯帽盖灭酒精灯——使灯芯的酒精与空气隔绝D存放酒精时远离火源——主要是防止酒精挥发3.某农田出现了土壤酸化板结现象,经调查,该农田长期施用化肥NH42SO4;下列推测中,错误的是ANH42SO4溶液的p H可能小于7B土壤板结可能是长期施用NH42SO4造成的C为了防止土壤酸化,施用NH42SO4的同时应加入CaOH2D草木炭主要含K2CO3可改良酸性土壤,说明K2CO3的溶液可能呈碱性4.下列认识或说法中,正确的是A向某固体中加入稀盐酸有气泡产生,可证明该物质中一定含有CO32- B常温下可用Fe与AgCl反应制取AgC可用过量的CuOH2除去CuSO4溶液中的少量H2SO4D分别将Mg、Fe、Cu、Ag放入稀盐酸中,可确定它们的活动性顺序5.下列关于水的叙述中,错误的是A自然界中水的p H均为7 B工农业生产需要大量的淡水C地球上总储水量很多,但淡水量很少 D水能以固态、液态、气态三种状态存在6.下列物质露置在空气中,能与氧气、水蒸气同时发生反应的是A铁粉 B生石灰 C浓硫酸 D氢氧化钠固体7.下列实验操作正确的是8. 在天平两边的托盘上各放一个质量相等的烧杯,并分别加入等质量、等质量分数的足量的稀盐酸,天平平衡;若向左盘烧杯中加入100 g 碳酸钙,充分反应后,要想使天平重新平衡,应向右盘烧杯中加入的物质可能是①56 g Zn 和Fe 2O 3的混合物 ②100 g MgCO 3和Al 的混合物 ③84g Mg 和Fe 的混合物 ④100 g BaCO 3和Cu 的混合物 A ①③ B ② C ②④ D ③④9. 亲爱的同学们,通过化学的学习你一定对一些化工生产中应用的原理有所了解,下列生产中不发生化学变化的是A .钢铁冶炼B .石灰石制生石灰C .分离液态空气制氧气D .氧炔焰焊接金属 10. 2005年11月,吉林石化公司双苯厂发生爆炸,造成松花江水质污染,主要污染物之一是苯;下图是苯的微观粒子模拟图,请根据图示判断下列说法中错误的是 A .苯的化学式为C 6H 6 B .苯由两种元素组成C .苯是由碳原子、氢原子直接构成的D .苯属于有机化合物11. 化学的研究成果在人类社会发展进程中起着重要的推动作用,下面的发明或发现不能归为化学研究范畴的是12. 通过化学的学习,我们重新认识了早已熟悉的空气和水,知道了自然界的水是 A 、纯净物 B 、混合物 C 、氧化物 D 、化合物13. 在进一步的学习中,我们还知道了许多健康常识,比如,下面四种做法中有益于人体健康的是A 、健康人应多吸纯氧B 、长期饮用硬水补钙C 、食用加碘盐D 、吸烟提神 14. 化学用语是学习和交流化学知识的通用语言,以下化学符号所表示的意义最多的是A 、FeB 、HC 、SO 42-D 、2H 2O15. 质量守恒定律是帮助我们认识化学反应实质的重要理论;请你利用这个定律判断:向Na 2CO 3溶液中滴加少量盐酸,所发生的化学反应是:Na 2CO 3 + HCl = + NaCl 中的物质是A 、H 2OB 、CO 2C 、H 2CO 3D 、NaHCO 316.生活中有许多宝贵的经验蕴含着化学知识,但也有一些做法是不正确的;请你利用所学的化学知识判断下面的做法不科学的是A、冰箱内放置木炭能除异味B、无色透明的塑料袋都可以盛装食品C、可用汽油洗衣服上的油污D、用热水配腌蛋的盐水,可加快食盐的溶解速率17.①酸雨②土壤中含汞等重金属③空气中CO含量增加都会对环境造成污染,其中由煤和石油等化石燃料燃烧造成的是A、①②③B、①③C、②③D、①②18.请你根据下列粒子的结构示意图判断,选项中哪种物质是由所提供的粒子构成的19.小英的妈妈在洗碗筷时,经常在水中加入一种物质,很快就能将“油乎乎”的菜盘洗得干干净净;小英的妈妈在水中加入的物质可能是A.汽油B.烧碱C.纯碱D.食盐水20.下列实验现象描述不正确的是A.红磷在空气中燃烧,产生大量白烟B.木炭在氧气中燃烧,发出白光,生成黑色固体C.细铁丝在氧气中燃烧,火星四射,生成黑色固体D.在空气中加热铜片,铜片表面有黑色固体生成21.在以下四种金属中,有一种金属的盐溶液与其它三种金属都能发生置换反应,这种金属是A、FeB、CuC、ZnD、Ag22.下列各组混合物中,用一种试剂不能将括号内杂质除去的是A.CuSO4Na2SO4B.CCuO C.CO2C0 D.NaClMgCl223.传统“陈醋”生产过程中有一步称为“冬捞夏晒”,是指冬天捞出醋中的冰,夏日曝晒蒸发醋中的水分,以提高醋的品质;假设用醋酸的质量分数为3%的半成醋,生产500g 5.4%的优级醋,过程中醋酸没有损失,捞出的冰和蒸发的水的总质量为A.500 g B.400 g C.200 g D.100 g24.如图所示,将气体X和气体Y同时通入液体Z,最终一定能看到液体变浑浊的是A. FeCl3 NaOH KCl BaNO32B. NaCl Na2CO3KNO3HClC. Na2SO4BaCl2K2CO3KNO3D. BaCl2CuSO4NaOH NaCl26.某物质由碳、氢、氧三种元素中的一种或几种组成,将该物质燃烧后的产物依次通过澄清石灰水和无水硫酸铜,观察到石灰水变浑浊,无水硫酸铜变成蓝色;有关该物质的组成,推断正确的是A. 一定有碳、氢、氧元素B. 一定有碳、氢元素,可能有氧元素C. 一定有碳元素,可能有氢、氧元素D. 一定有碳、氧元素,可能有氢元素27.向一定质量的稀盐酸中加入镁粉至过量,若下面图像中横坐标表示镁粉的质量,则纵坐标表示A. 溶液的质量B. 稀盐酸的质量C. 氯化镁的质量D. 生成气体的质量28.在化合、分解、置换、复分解四类反应中,可能生成水的反应共有A.1类 B.2类 C.3类 D.4类29.1O.6克不纯的碳酸钠固体与足量的稀盐酸反应,生成4.4克二氧化碳.则碳酸钠固体中可能含有的杂质是A.碳酸镁和碳酸钙 B.碳酸钾和碳酸铵 C.碳酸钡和碳酸锌 D.碳酸钡和氯化钠克20 %的氢氧化钠溶液和1O克20%的稀硫酸充分混合,混合后的溶液与下列物质不能发生反应的是A.铁 B.氯化钡溶液 C.硫酸铜溶液 D.氢氧化钡溶液31. 右图1表示甲、乙两种固体的溶解度随温度变化的情况;右图2A、B试管中分别盛有甲、乙两种固体的饱和溶液,试管底部均有未溶解的固体;向烧杯中加入一种物质,发现A试管中固体增多.B试管中固体减少,则加入的物质是A.硝酸铵 B.浓硫酸 C.氢氧化钠 D.生石灰32. 以下关于化学新技术与其试图解决的主要问题不相符的是A.海尔洗衣机厂开发的“不用洗衣粉的洗衣机”——解决污染问题B.厦门三达膜技术公司开发的“海水淡化膜”——解决资源问题C.中科院开发的“用CO2制取全降解塑料”——解决能源问题D.应用于计算机领域的“导电塑料”——解决材料问题33. 下列说法中不正确的是A金属元素原子的最外层电子数目一般少于4个 B非金属元素的原子一般比较容易获得电子C稀有气体元素原子的最外层都有8个电子 D单质的化合价为034.下列有关实验设计方案或实验事实的叙述正确的是A降温时,饱和溶液可能不析出晶体B将氧气和氢气的混合气体通过灼热的氧化铜以除去氢气C将FeOH3加入到滴有酚酞试液的蒸馏水中,溶液显红色D在混有Na2SO4的NaOH溶液中,加入适量的BaCl2溶液,过滤可得到纯净的NaOH溶液35.向氧化铜和铁粉的混合物中,加入一定量的稀硫酸,反应停止后,过滤,除去不溶物;向滤液中加一铁片,未看到铁片有任何变化;下列分析正确的是A滤出的不溶物中一定含有Cu和Fe B滤出的不溶物中一定含有CuC滤液中一定不含有CuSO4 D滤液中一定不含有FeSO4和H2SO436.将露置在空气中已部分变质的NaOH样品,溶于水配成溶液,向其中滴加过量的稀盐酸;下列示意图能正确反映其中变化的是37.一定条件下,在托盘天平的左右两盘上各放一只烧杯,均加入质量分数相同、体积相等的稀盐酸,调整天平呈平衡状态;下列实验操作,最终仍能使天平保持平衡的是A向左、右两烧杯中分别加入5.6 g Fe和1.8 g Al,两种金属完全溶解B向左、右两烧杯中分别加入相等质量的Al、Zn,两种金属完全溶解C向左、右两烧杯中分别加入相等质量的Fe、CaO,反应后盐酸有剩余D向左、右两烧杯中分别加入相等质量的Mg、Al,反应后两种金属均有剩余38. 玻璃钢是一种A.硅酸盐材料 B.塑料 C.合金 D.复合材料39. 某单质X能从某溶液中置换出单质Y,由此推断下列说法中正确的是A.X一定是排在金属活动顺序表中氢以前的金属 B.X是金属时,Y可能是金属,也可能是非金属C.X是金属时,Y一定比X活泼 D.X、Y都是金属时,Y一定比X活泼40. 小明测得某食盐溶液中含有氯元素的质量分数为%,如果以计算,则该盐水中所含的质量分数为A.% B.% C.% D.%41. 给一无色溶液滴入数滴无色酚酞试液,溶液使酚酞变红,这说明该溶液是A.酸性溶液 B.酸的水溶液 C.碱性溶液 D.碱的水溶液42. .在混有少量铜粉的铁粉中加入足量稀硫酸,产生氢气的质量为A.大于 B.等于 C.小于 D.无法确定43. 检验某可燃烧的化合物是否含有氢、碳、氧3种元素,在该物质完全燃烧后还必须进行的实验是:①用带火星的木条检验;②用无水硫酸铜检验;③用澄清石灰水检验;④对反应物、生成物进行称量;以下选项中正确的是A.①②③④ B.②③④ C.①②③ D.②③44. 下列四个图像分别表示对应的四种操作过程,其中表示正确的图像是A.向pH=1的酸溶液中不断加水B.向pH=1的硫酸溶液中逐滴加入pH=13的氢氧化钠溶液C.某温度下,向一定量的水中持续加入食盐并不断搅拌 m表示加入食盐的质量,A%表示溶质质量分数D.等质量的锌、铁与足量的稀硫酸反应,产生氢气的质量M与反应时间t的关系图45..在25℃时,向饱和的澄清石灰水中,加入少量的氧化钙,再恢复到25℃,下列说法中正确的是A.溶质的质量不变 B.溶质的质量减少 C.溶质的质量分数减少 D.溶质的质量分数增大46. 一瓶溶质质量分数为10%的溶液,蒸发掉60g水后,溶质质量分数变为20%,则原溶液中溶质的质量是A.12克 B.60克 C.120克 D.无法确定47. 初中化学里,我们学习过以下常见的酸、碱、盐:HCl、H2SO4、NaOH、CaOH2、Na2 CO3、NaCl,请你整理归纳,这六种物质两两相互能发生化学反应的共有A.7个 B.6个 C.5个 D.4个48. 将质量相等的A、B、C三种金属,同时分别放入三份溶质质量分数相同且足量的稀盐酸中,反应生成H2的质量与反应时间的关系如图所示;根据图中所提供的信息,得出的结论正确的是;已知:A、B、C在生成物中均为+2价A.放出H2的质量是A>B>CB.金属活动性顺序是A>B>CC.反应速率最大的是AD.相对原子质量是C>B>A49.有机合成材料的出现是材料发展史上的一次重大突破,下列叙述错误的是A.塑料、纤维、橡胶均属于有机合成材料 B.热固性塑料可用作炒菜锅的手柄 C.合成纤维的强度高、弹性好、耐磨、耐化学腐蚀 D.合成橡胶可用于生产汽车轮胎50. 下列说法错误的是A.淀粉酶只能催化淀粉的水解反应 B.油脂包括植物油和动物的脂肪C.微量元素均对人体有害 D.甲醛水溶液浸泡过的水产品,由于蛋白质变质,食用会危害人体健康51. 到银行存、取款时,填写的单据需长期保存,书写时必须用A.铅笔 B.圆珠笔 C.红墨水笔 D.碳素墨水笔52. 有一包白色固体可能含有碳酸钙、硫酸铵、碳酸钠、氢氧化钡,将此固体粉末放入足量水中溶解,除有刺激性气味的气体产生外,出现的白色沉淀有部分溶于稀硝酸信息:BaOH属于可溶性强碱.则原白色固体内2A.一定含有硫酸铵、氢氧化钡、碳酸钠 B.一定不含有碳酸钙、碳酸钠、氢氧化钡C.可能同时含有碳酸钙和碳酸钠 D.可能含有氢氧化钡和硫酸铵53. “绿色化学”是当今社会提出的一个新概念,其中包含“化学反应绿色化”,即要求原料中的原子全部转入到产品中;下列反应一定符合“化学反应绿色化”要求的是A置换反应 B分解反应 C化合反应 D复分解反应54. 清洗内壁粘有油污的试管要用到的是A.酒精B.稀盐酸C.氯化钠溶液D.洗衣粉55.下列实验装置不能用来证明质量守恒定律的是56.四会生产的翡翠是人们喜爱的一种装饰品,翡翠的主要成份是硬玉化学式为NaAlSi2O6;下列有关说法正确的是A.翡翠是一种纯净物 B.硅元素的化合价为+4价C.硬玉含有10个原子 D.翡翠由钠、铝、硅、氧四种元素构成57.下列对某一主题知识归纳全部正确的是A.性质与用途B.生活常识C.化学之最 D.初中化学的“三”58. 已知某两种物质在光照条件下能发生化学反应,其微观示意图如下:说明:一种小球代表一种原子则下列说法正确的是A.图示中的反应物都是单质 B.图示中共有4种分子C.该反应属于置换反应 D.该图示不符合质量守恒定律59. 甲酸HCOOH 是一种无色、有刺激性气味的液体,与浓硫酸混合加热的反应为:HCOOH=CO ↑+H 2O;实验室可利用下图装置制取CO 并还原CuO :下列说法错误的是A.甲酸生成CO 的反应属于分解反应 B .实验中应先通入CO 、后加热CuOC. 硬质玻璃管中的实验现象是黑色固体变为红色固体D. 硬质玻璃管和固体的总质量反应后增大60. 下表中“—”表示相连的物质间能发生反应,“→”表示这种物质可转化为另一种物质;甲、乙、丙、丁四种物质符合对应“转化关系”的是 61. 化学中常常出现“1+1≠2”的有趣现象,但也有例外;下列符合“1+1=2”的事实是A. 20℃,1 L 水与1 L 酒精混合后的体积等于2 LB. 20℃,1 g 镁与1 g 稀硫酸充分反应后所得的溶液质量为2 gC. 20℃,1 g 硫粉在1 g 氧气中完全燃烧后生成2 g 二氧化硫D. 20℃,1 g 硝酸钾饱和溶液中加入1 g 硝酸钾固体能得到2 g 硝酸钾溶液 62. 月球的土壤中吸附着数百万吨的氦He-3,其原子核中质子数为2、中子数为1,下列关于氦He-3元素的说法正确的是 A .原子核外电子数为3 B .相对原子质量为2 C .原子的核电荷数为3 D .原子结构示意图为ABCD转化关系物质 甲 C Na 2CO 3 CaOH 2 Fe 乙O 2 CaOH 2 HCl HCl 丙CuO MgCl 2 CO 2 CuCl 2 丁CO 2H 2SO 4NaOHNaOH63.下列装置操作图不能用于检查气密性的是64.某同学对所学部分化学知识归纳如下,其中有错误的一组是A 物质性质与用途B 日常生活经验O2助燃—气焊切割金属H2O2分解放出O2—实验室制O2衣服上圆珠笔油—用汽油或酒精搓洗区别棉和羊毛织物—取少量,点燃闻气味C 安全常识D 化学与生活煤气泄漏—打110报警皮肤沾上浓硫酸—用水冲洗,再涂稀醋酸维生素C—缺乏时引起坏血病糖类、蛋白质—必需摄取的营养素65.研究表明,许多金属氧化物对氯酸钾的分解有催化作用;下表是不同金属氧化物作催化剂,氯酸钾剧烈反应时的温度:氧化物氧化铁氧化铝氧化铜氧化镁剧烈反应的温度/℃490 540 350 546实验室用氯酸钾制取氧气,如果不用二氧化锰作催化剂,最好选用A.氧化铁 B.氧化铝 C.氧化铜 D.氧化镁66.类推是化学学习中常用的思维方法;现有以下类推结果:①酸碱中和反应生成盐和水,所以生成盐和水的反应一定是中和反应;②碱的水溶液显碱性,所以碱性溶液一定是碱溶液;③氧化物都含有氧元素,所以含有氧元素的化合物一定是氧化物;④有机物都含碳元素,所以含碳元素的化合物都是有机物;其中错误的是A.只有① B.只有①②③ C.只有②③④ D.全部67.右下图中“—”表示相连的物质间在一定条件下可以发生反应,“→”表示甲在一定条件下可与某种物质直接反应生成丙;下表四组选项中,符合图中要求的是甲乙丙丁ABaCl2CuSO4BaOH2HClB O2CO Fe3O4CC FeCuCl2Mg HClC Cu HCl CuO Mg22;假设每步反应都是完全的,通过下列试剂的先后顺序中,正确的是①浓硫酸②苛性钠溶液③灼热的氧化铜A.①②③ B.②①③ C.③②① D.②③①69.提醒人们注意车船上严禁存放易燃品的图标是70.近来有研究报告称:除去“普通水”里含有的氮气和氧气后,水的去污能力将大大增强;下列对此说法的理解不正确的是A.“普通水”中含有氮分子 B.氮气和氧气在水中有一定的溶解性C.“普通水”中含有氧分子 D.除去氧气后的水就不再含有氧元素了71. 过氧化氢H 2O 2是一种无色粘稠液体,易分解为水和氧气,常用作氧化剂、漂白剂和消毒剂,为了贮存、运输、使用的方便,工业上将过氧化氢转化为固态的过碳酸钠晶体2Na 2CO 3·3H 2O 2,该晶体具有碳酸钠和过氧化氢的双重性质;接触下列物质不会使过碳酸钠失效的是A .红砖粉末B .氢氧化钙C .氯化钠D .硫酸72..如右图所示,打开止水夹,将液体A 滴人试管②中与固体B 接触;若试管①中的导管口没有气泡产生,则液体A 和固体B 的组合可能是下列中的A .过氧化氢溶液和二氧化锰B .水和硝酸钾C .水和氢氧化钠D .水和生石灰 73. 在一定条件下,置于密闭容器中的下列各组物质充分反应后,再冷却至常温;密闭容器中只有一种气态物质的是A.质量比为1:16的H 2和02B.质量比为3:9的C 和02C.质量比为1:4的CH 4和02D.质量比为7:2的CO 和0274. 成语、诗词话科学——对下列诗句所描述的现象中包含化学内容的解释,你认为错误的是75.A .图①是向一定量稀盐酸和氯化钙的混合溶液中不断滴入碳酸钠溶液至过量 B .图②是用H 2还原CuO 来测定CuO 中铜元素的含量 C .图③是向饱和的NaCl 溶液中不断加水 D .图④是用适量的KClO 3和MnO 2混合物加热制O 276. 小明放假后发现自家责任田土壤酸化、板结,他根据所学化学知识发现是长期使用硫酸铵化肥所致;为了改良土壤状况,他采取了下列措施;你认为可行的办法是A .停止使用硫酸铵,改用硫酸钾B .来年施肥时,把硫酸铵和熟石灰混用C .来年施肥时把硫酸铵和生石灰混用D .庄稼收割后,向田地里洒草木灰 77. 在CO 和CO 2的混合气体中,氧元素的质量分数是64%,将该气体5g 通过足量的灼热的CuO 粉末,完全反应后,气体通过足量的澄清石灰水得到白色沉淀的质量是A .5gB .C .15gD .20g78. 在一个密闭容器内有X 、Y 、Z 、Q 四种物质,在一定条件下充分反应,测得反应前后各物质的质量如下:则该密闭容器中发生的反应属于A .化合反应B .分解反应 c .置换反应 D .复分解反应79. 在由BaCl 2、HCl 组成的混合溶液中,滴加Na 2CO 3溶液至足量,则下图中对产生沉淀的质量m 与加入Na 2CO 3溶液的体积V 之间的关系,描述正确的是80. 现有CO 、CO 2混合气体,小芳同学按如下顺序进行操作右图所示装置中a 是弹簧夹,b 是分液漏斗活塞:①关b 开a ; ②通入混合气体; ③收集气体; ④关a 开b ; ⑤收集气体;通过上述操作小芳A.只收集到CO气体气体B.只收集到CO2气体C.先收集到CO气体,后收集到CO2气体,后收集到CO气体D.先收集到CO281. 2005年诺贝尔化学奖授予法国和美国的三位科学家,以表彰他们在烯烃复分解反应研究方面的重要贡献;烯烃复分解反应的过程被化学家描述为“交换舞伴的交谊舞”;下列图示可以被理解为烯烃复分解反应的是答案: 2. D 3;C 10;C 11;C 18;C 71. C。

(易错题精选)初中数学有理数的运算难题汇编含解析

(易错题精选)初中数学有理数的运算难题汇编含解析

(易错题精选)初中数学有理数的运算难题汇编含解析一、选择题1.港珠澳大桥东起香港国际机场附近的香港口岸人工导,向西横跨伶仃洋海域后连接珠海和澳门人工岛,止于珠海港湾,全长55千米,设计时速100千米/小时,工程项目总投资额1269亿元,用科学记数法表示1269亿元为()A.1269×108B.1.269×108C.1.269×1010D.1.269×1011【答案】D【解析】【分析】科学记数法的表示形式为a×10n的形式,其中1≤|a|<10,n为整数.确定n的值时,要看把原数变成a时,小数点移动了多少位,n的绝对值与小数点移动的位数相同.当原数绝对值>10时,n是正数;当原数的绝对值<1时,n是负数.【详解】1269亿=1.269×1011故选D.【点睛】此题考查科学记数法的表示方法.科学记数法的表示形式为a×10n的形式,其中1≤|a|<10,n为整数,正确确定a的值以及n的值是解题关键.2.计算12+16+112+120+130+……+19900的值为()A.1100B.99100C.199D.10099【答案】B【解析】分析:直接利用分数的性质将原式变形进而得出答案.详解:原式=11111 1223344599100 ++++⋯+⨯⨯⨯⨯⨯=111111112233499100 -+-+-+⋯+-,=1-1 100=99 100.故选B.点睛:此题主要考查了有理数的加法,正确分解分数将原式变形是解题关键.3.已知实数a,b,c,d,e,f,且a,b互为倒数,c,d互为相反数,e的绝对值为,f 的算术平方根是8,求2125c d ab e ++++( )A .92B .92C .92+92-D .132 【答案】D【解析】【分析】 根据相反数,倒数,以及绝对值的意义求出c+d ,ab 及e 的值,代入计算即可.【详解】由题意可知:ab=1,c+d=0,=e f=64,∴222e =±=(4=,∴2125c d ab e ++++=11024622+++=; 故答案为:D【点睛】 此题考查了实数的运算,算术平方根,绝对值,相反数以及倒数和立方根,熟练掌握运算法则是解本题的关键.4.我国是世界上严重缺水的国家之一,目前我国每年可利用的淡水资源总量为27500亿米3,人均占有淡水量居全世界第110位,因此我们要节约用水,27500亿用科学记数法表示为( )A .275×104B .2.75×104C .2.75×1012D .27.5×1011【答案】C .【解析】试题解析:将27500亿用科学记数法表示为:2.75×1012.故选C .考点:科学记数法—表示较大的数.5.2018年全国高考报名总人数是975万人,用科学记数法表示为( )A .30.97510⨯人B .29.7510⨯人C .69.7510⨯人D .70.97510⨯人【答案】C【解析】【分析】根据科学计数法的定义进行作答.【详解】A.错误,应该是69.7510⨯;B.错误,应该是69.7510⨯;C.正确;D. 错误,应该是6⨯.综上,答案选C.9.7510【点睛】本题考查了科学计数法的定义:将一个数字表示成(a⨯10的n次幂的形式),其中1≤a<10,n表示整数,熟练掌握科学计数法的定义是本题解题关键.6.清代·袁牧的一首诗《苔》中的诗句:“白日不到处,青春恰自来.苔花如米小,也学牡丹开.”若苔花的花粉直径约为0.0000084米,则数据0.0000084用科学记数法表示为()A.8.4×10-5B.8.4×10-6C.84×10-7D.8.4×106【答案】B【解析】【分析】绝对值小于1的正数也可以利用科学记数法表示,一般形式为a×10-n,与较大数的科学记数法不同的是其所使用的是负指数幂,指数由原数左边起第一个不为零的数字前面的0的个数所决定.【详解】7.我县人口约为530060人,用科学记数法可表示为( )A.53006×10人B.5.3006×105人C.53×104人D.0.53×106人【答案】B【解析】【分析】根据科学记数法的定义及表示方法进行解答即可.【详解】解:∵530060是6位数,∴10的指数应是5,故选B.【点睛】本题考查的是科学记数法的定义及表示方法,熟知以上知识是解答此题的关键.8.(﹣1)4可表示为()A.(﹣1)×4 B.(﹣1)+(﹣1)+(﹣1)+(﹣1)C.﹣1×1×1×1 D.(﹣1)×(﹣1)×(﹣1)×(﹣1)【答案】D【解析】【分析】根据有理数乘法的定义可得出结论.【详解】(﹣1)4=(-1)×(-1)×(-1)×(-1).故答案选D.【点睛】本题考查的知识点是有理数的乘方,解题的关键是熟练的掌握有理数的乘方.9.下列说法中,正确的是()A.在数轴上表示-a的点一定在原点的左边B.有理数a的倒数是1 aC.一个数的相反数一定小于或等于这个数D.如果a a=-,那么a是负数或零【答案】D【解析】【分析】根据实数与数轴的对应关系、倒数、相反数、绝对值的定义来解答.【详解】解:A、如果a<0,那么在数轴上表示-a的点在原点的右边,故选项错误;B、只有当a≠0时,有理数a才有倒数,故选项错误;C、负数的相反数大于这个数,故选项错误;D、如果a a=-,那么a是负数或零是正确.故选D.【点睛】本题考查了数轴、倒数、相反数、绝对值准确理解实数与数轴的定义及其之间的对应关系.倒数的定义:两个数的乘积是1,则它们互为倒数;相反数的定义:只有符号不同的两个数互为相反数;绝对值的性质:一个正数的绝对值是它本身;一个负数的绝对值是它的相反数;0的绝对值是0.10.大量事实证明,治理垃圾污染刻不容缓.据统计,全球每分钟约有8500000吨污水排入江河湖海,这个排污量用科学记数法表示为()A.8.5×105 B.8.5×106C.85×105 D.85×106【答案】B【解析】【分析】根据科学记数法的表示形式:a×10n,其中1≤|a|<10,n为整数.解答即可.【详解】8500000=8.5×106,故选B.【点睛】此题考查科学记数法的表示方法.科学记数法的表示形式为a×10n的形式,其中1≤|a|<10,n为整数,表示时关键要正确确定a的值以及n的值.11.预计到2025年,中国5G 用户将超过460 000 000,将460 000 000用科学计数法表示为( )A .94.610⨯B .74610⨯C .84.610⨯D .90.4610⨯【答案】C【解析】【分析】科学记数法的表示形式为a×10n 的形式,其中1≤|a|<10,n 为整数.确定n 的值时,要看把原数变成a 时,小数点移动了多少位,n 的绝对值与小数点移动的位数相同.当原数绝对值大于10时,n 是正数;当原数的绝对值小于1时,n 是负数.【详解】460 000 000=4.6×108.故选C .【点睛】此题考查科学记数法的表示方法.科学记数法的表示形式为a×10n 的形式,其中1≤|a|<10,n 为整数,表示时关键要正确确定a 的值以及n 的值.12.一周时间有604800秒,604800用科学记数法表示为( )A .2604810⨯B .56.04810⨯C .66.04810⨯D .60.604810⨯ 【答案】B【解析】【分析】科学记数法的表示形式为10n a ⨯的形式,其中110,a n ≤<为整数.确定n 的值时,要看把原数变成a 时,小数点移动了多少位,n 的绝对值与小数点移动的位数相同.当原数绝对值1>时,n 是正数;当原数的绝对值1<时,n 是负数.【详解】604800的小数点向左移动5位得到6.048,所以数字604800用科学记数法表示为56.04810⨯,故选B .【点睛】本题考查科学记数法的表示方法.科学记数法的表示形式为10n a ⨯的形式,其中110,a n ≤<为整数,表示时关键要正确确定a 的值以及n 的值.13.据资料显示,地球的海洋面积约为36000万平方千米,请用科学记数法表示地球海洋面积约为多少平方千米( ).A .73610⨯B .83.610⨯C .90.3610⨯D .43.610⨯【答案】B【解析】【分析】先将36000万平方千米化为360000000平方千米,再根据科学计数法的概念进行表示,即可得到答案.【详解】36000万平方千米=360000000平方千米,将360000000用科学记数法表示为83.610⨯,则用科学记数法表示地球海洋面积约为83.610⨯平方千米,故选:B .【点睛】本题考查科学计数法.科学记数法的形式为:10n a ⨯,其中110a ≤≤,n 为整数.14.据报道,2019年元旦小长假云南省红河州共接待游客约为7038000人,将7038000用科学记数法表示为( )A .570.3810⨯B .67.03810-⨯C .67.03810⨯D .60.703810⨯【答案】C【解析】【分析】科学记数法的表示形式为a×10n 的形式,其中1≤|a|<10,n 为整数.确定n 的值时,要看把原数变成a 时,小数点移动了多少位,n 的绝对值与小数点移动的位数相同.当原数绝对值>10时,n 是正数;当原数的绝对值<1时,n 是负数.【详解】将7038000用科学记数法表示为:7.038×106.故选:C .【点睛】此题考查科学记数法的表示方法.解题关键在于掌握科学记数法的表示形式为a×10n 的形式,其中1≤|a|<10,n 为整数,表示时关键要正确确定a 的值以及n 的值.15.2018年4月10日,“2018博鳌亚洲论坛”在我国海南省博鳌小镇如期举行,据统计,在刚刚过去的一年,亚洲经济总量为29.6万亿美元,高居全球七大洲之首.数据“29.6万亿”用科学记数法可表示为( )A .2.96×108B .2.96×1013C .2.96×1012D .29.6×1012【答案】B【解析】【分析】科学记数法的表示形式为a ×10n 的形式,其中1≤|a |<10,n 为整数.确定n 的值时,要看把原数变成a 时,小数点移动了多少位,n 的绝对值与小数点移动的位数相同.当原数绝对值≥1时,n 是正数;当原数的绝对值<1时,n 是负数.【详解】16.下面是一名学生所做的4道练习题:①224-=;②336a a a +=;③44144mm -=;④()3236xy x y =。

七年级英语单项选择100题易错题集锦含解析

七年级英语单项选择100题易错题集锦含解析

七年级英语单项选择100题易错题集锦含解析一、选择题1.—Sorry, I don't know how many colours there are in a rainbow.—Are you joking? This is just ________ knowledge.A.natural B.general C.proper D.ancient2.— You see, more and more cows are getting sick.—If the problem is so ________, the farm will be closed from tomorrow on.A.heavy B.popular C.strong D.serious3.I like collecting old stamps because they are ________.A.simple B.valuable C.impossible D.natural 4.—How do you like the talk show?—I think it's ________, but some people think it's so ________.A.wonderful enough; bored B.enough wonderful; boring C.wonderful enough; boring D.enough wonderful; bored5.The basketball match will be covered _______ on TV tonight.A.lively B.live C.living D.alive6.The Spring Festival is one of the ______ festivals in China and everyone loves to celebrate it. A.modern B.traditional C.international D.ancient 7.There isn’t an airport near where I live. The _______ one is about 90 miles away. A.busiest B.farthest C.newest D.nearest8.As the number of the novel coronavirus infections grows___________, the World Heath Organization takes active steps to control the serious disease.A.more B.larger C.higher D.wider 9.Thanks a lot for offering such _______ to me in my research.A.usual advice B.important advice C.a usual trip D.valuable trip 10.—Do you know about the story of the Little Horse Crossing the River?—Yes, at last the little horse finishes crossing the river and he knows how ________the river is. A.wide B.long C.deep D.clear 11.—What new skills have you unlocked during the long winter holiday?—Cooking. It has become more _______ among people and I can cook nice dishes now. A.exciting B.difficult C.different D.popular 12.—How do you feel about the dish?—Look! This is nothing but ________ vegetable soup.A.famous B.wonderful C.unusual D.common 13.—What's wrong with your radio?—The sound coming out is not ________.A.clean B.clear C.fresh D.well14.I think “heroes in harm’s way(逆行者)” must be one of the ________words on the Internet last year.A.hottest B.widest C.cleverest D.driest15.— Are you a fan of the TV show Chinese Poetry Conference ?—Of course. I’ve never missed any of episodes and I am __________ by these players’ excellent knowledge of classical poems.A.tired B.satisfied C.bored D.amazed16.He takes part in all kinds of activities in his _____ time.A.busy B.spare C.high D.empty17.I'm always ____________ before the exam. I often try to make myself calm down by taking a deep breath.A.relaxed B.bored C.nervous D.happy 18.—Peter has good grades in all his subjects, but he never shows off.—I agree. He is very________.A.humorous B.organized C.modest D.generous19.— How do you find the price now?— As a________rule, prices follow needs.A.private B.general C.central D.fixed 20.—Have you unlocked any new skills during the long winter holiday?—Yes. Cooking has become more and more ____ and I can cook nice dishes now. A.comfortable B.difficult C.different D.popular21.— How was your job interview yesterday?—Oh, I couldn't feel ________. I could hardly answer most of the questions they asked.A.worse B.easier C.better D.happier 22.—Dad, I've tried my best but I still can't solve these problems.—Don't worry, my son. No one is ________ and everyone fails from time to time. A.successful B.confident C.perfect D.excellent23.Mr Zheng is so ______that he has donated five million yuan to the schools in his hometown. A.energetic B.patient C.humorous D.generous24.As the population ________, the world seems to be smaller.A.increases more B.increase larger C.grows larger D.grows more 25.My little sister is ________ and she always asks me different kinds of strange questions. A.creative B.wise C.curious D.generous 26.—Henry, you seem ________ than before. What are you doing these days?—Well, I am preparing for the coming examination.A.busier B.happier C.lazier D.healthier27.It’s ________ knowledge that moods can have an influence on our health.A.unusual B.special C.general D.common28.—I can’t afford the red shoes.—What about the black pair? The price is a little ________.A.cheaper B.lower C.higher D.more expensive 29.—What do you think of the new car produced by BYD?—Oh, its improved system gives people a ________ ride even on mountain roads.A.similar B.terrible C.strange D.smooth 30.Students should be ________ that even a small thing like saving water and looking after a tree can make a big difference to our environment.A.alone B.awake C.aware D.afraid31.— Why do English people talk so often about the weather when starting the talk?—Because the weather is a (an) ________ topic.A.safe B.serious C.awful D.exciting 32.Although this may sound like a ________ process, great care is needed.A.stupid B.similar C.simple D.strict 33.—How was your exam the day before yesterday?—Well, I feel quite good. I made ________ mistakes than before.A.fewer B.the fewest C.less D.the least 34.— Would you mind not making much noise? Mum is sleeping.—Sorry, I didn’t know. I thought she was ________.A.alone B.asleep C.awake D.afraid 35.—Linda is practising the violin for an hour these days.—I see. It’ll make her ________ enough to perform on stage tonight.A.active B.humorous C.confident D.patient36.The girl’s voice sounds ________. Maybe she can become a good singer when she grows up. A.terrible B.well C.sweet D.wonderfully 37.You may meet many difficulties in the future, you should learn to be ________ enough to take on any challenge.A.confident B.modest C.generous D.curious38.My little cousin is a(n) ________ boy and he always comes up with new ideas for class activities.A.creative B.curious C.organized D.energetic 39.— How do you find the price now?— As a ________ rule, prices follow needs.A.private B.general C.central D.difficult 40.—You haven’t said a ________ word since last Friday. What’s wrong?—Nothing. Just let me alone.A.simple B.single C.similar D.silent41.The speaker showed ________ examples to make the science report easy to understand. A.awful B.proper C.stupid D.tiring 42.There’s a ________ feeling that a high price means good quality.A.sudden B.joyful C.hard D.general 43.—What do you think of the film Hi, Mom directed by Jia Ling?—I have never seen a ________ one before. I can’t wait to see it again.A.best B.worse C.better D.worst44.Our monitor Jenny is so ________ that she always keeps things in good order.A.organized B.practical C.generous D.modest45.This is the chance he needs to make a ________ start.A.curious B.patient C.fresh D.natural 46.Because of the war, love and happiness were totally ________ from little Tom’s childhood. A.separate B.absent C.extra D.blind47.— Mary can get good marks in all her subjects, but she never shows off.— I agree. She is ________.A.generous B.modest C.patient D.curious48.—It will be ________.—That’s great! The whole world will be white.A.sunny B.cloudy C.snowy D.foggy49.This kind of drink tastes ________ but there’s only ________ in this bottle. I’d like some more.A.good;a little B.well;a little C.good;little D.well;little 50.You’ve watched the boring soap opera thousands of times! Why don’t you go outside and find something ________ doing?A.useful B.cheerful C.enjoyable D.worth二、选择题51.Because of COVID-19, this summer holiday will begin ________ July 18.A.on B.in C.for D.at52.You shouldn’t eat so much chocolate _________ mea ls. Because it will affect your appetite. A.except B.through C.between D.unless53.The exercise is ________ my ability and it’s hard for me to work it out.A.over B.against C.beyond D.through54.The blue planet is so far from the earth that radio signals, travel ________ the speed of light, take 16 hours to reach the spacecraft.A.for B.in C.on D.at55.—I want to visit Liaoning History Museum. Is it open today?—No. It opens every day ________ Monday.A.except B.till C.between D.after56.The chopsticks are ________ wood.A.made of B.made from C.made in D.made with 57.The girl is ________ a singer ________ everyone in her hometown.A.well known as; for B.well-know as; toC.well known as; to D.best known for; for58.I met Nancy ________ my way home yesterday.A.in B.at C.by D.on59.The workers will build a new road ________ the two villages.A.from B.among C.at D.between60.My family get together and have a big dinner ________ Sundays.A.at B.in C.on D.to61.________ a spring morning, a bird flew into our classroom and we were very excited to see it. A.In B.On C.At D.For 62.—Sorry, I can’t finish the exercise on time.—Never mind. It is ________ the abilities of most of the class.A.across B.on C.over D.beyond63.My family is always ___________ me no matter what I decide to do. That makes me very pleased.A.above B.behind C.against D.through 64.—Hi, Mom directed by Jia ling is a hit ________ this year.—It really is. It shows us the deep love between a mother and a daughter.A./ B.in C.on D.at65.— The Dragon Boat Festival falls_______May or June every year.—Yes, this year’s Dragon Boat Festival is_______June 25th.A.in; on B.on; in C.in; in D.on; on 66.Switzerland lies ________ France, Germany, Austria and Italy.A.between B.among C.against D.beyond67.—It's reported that Stanley Ho Hung-sun passed away on May 26th at the age of 98.—The whole country felt sad about that. As a successful businessman, his contribution to society and love for the motherland went far ________ his wealth.A.beside B.over C.beyond D.above68.To our joy, Tom pleased everybody by making his dog walk ________ two legs.A.by B.over C.from D.on69.—I’ve been a League member for about two years. What about you?—I joined the League ___________May, 2017.A.in B.on C.at D.by70.Family is always _________ me, so I can follow my dreams with great courage. A.beyond B.forward C.past D.behind71.— What do you think of those smart kids in the game show?— There is no doubt that many of them have a gift ________ maths.A.for B.in C.on D.at72.To my pleasure, my family is always ________me, so I can follow my dreams with great courage.A.past B.above C.upon D.behind 73.—Jack, you should put the things away in your room. It is ________ a terrible mess!—OK, I’m coming, Mum!A.on B.at C.in D.for74.The exercise was __________ the abilities of most students, so very few could work it out. A.beyond B.over C.against D.through75.If success is a gate, the road ________ this gate must be full of difficulties.A.beyond B.opposite C.towards D.across76.— M y aunt’s 3-year-old daughter can eat a meal with chopsticks.— Really? Most children ________ her age still use spoons.A.of B.in C.on D.for77.— When will Mr. Smith arrive?— ________ September 6th.A.At B.In C.On D.For78.—A serious study of physics is impossible ________ some knowledge of maths.—I couldn’t agree more. So we should also learn maths well.A.among B.between C.against D.without 79.—The boy is tall enough ________ his age.—Yes, I was much shorter when I was his age.A.of B.at C.from D.for80.—The earthquake in Ya’an took place ________ two past eight ________ the morning of April 20th.—Yes, some people were still sleeping for it was weekend.A.in; on B.on; in C.at; in D.at; on 81.There is a stone bridge ________ the river in front of my house.A.over B.under C.above D.below82.Wu Mengchao, known as the “father of Chinese hepatobiliary surgery” passed away________ the age of 99 on Saturday.A.on B.in C.at D.by83.V olunteering is a good way to experience life ________ the campus (校园). Take an active part in it, and you will learn more about the world.A.over B.beyond C.against D.above84.To fully understand the writer, we must read not only between the lines, but sometimes________ the lines.A.within B.beyond C.beside D.among85.The 20th China Jiangning Hengxi Watermelon Festival was held ________ May this year. A.at B.on C.in D.from86.In western countries, children play “trick or treat” ________ the evening of October 31st. A.at B.in C.on D.to 87.Anyone who can find the clues ________ the case will get a reward of 5,000 yuan. A.with B.to C.at D.from88.The underground in this city has been ________ service for almost 3 years.A.on B.in C.at D.of89.Don’t be afraid of difficulties. Remember: kites rise highest ________ the wind, not with it. A.over B.against C.across D.along90.The ending of the film Diary of Dinosaurs was so surprising and fully went ________ my imagination.A.across B.over C.through D.beyond91.________small actions, like reusing water, we can make a great difference to our world. A.Across B.Beyond C.Through D.Against 92.—How did you get to the zoo, Helen?—I went to the bus station ________ my bike, and took the No. l bus to the zoo.A.on B.by C.in D.with93.A study shows that rude languages spoken to children may have bad results that go ________ those of beating them.A.against B.beyond C.except D.with94.Last week, Oprah Winfrey had an interview ________ Harry and Meghan.A.with B.to C.about D.on95.Don’t be afraid of difficulties. Remember: kites rise highest ________ t he wind, not with it. A.against B.above C.across D.along96.Some of the technology we’ve seen on screen is ________ our ability to create. But that might not be true for long.A.against B.during C.beyond D.through 97.—Thanks for looking after me ________ my illness, Millie.—Don’t mention it. That’s what friends are for.A.through B.among C.with D.across 98.—Thanks for looking after me ________ my illness, Millie.—Don’t mention it. That’s what friends are for.A.beyond B.through C.across D.with99.New York City, also known ________ Big Apple, becomes one of the world’s greatest business and cultural centers.A.as B.by C.for D.to100.It is a good idea to experience life ________ the school by volunteering. Take an active part in it, and you will make a difference to the world.A.above B.beyond C.over D.against【参考答案】***试卷处理标记,请不要删除一、选择题1.B解析:B【详解】句意:——对不起,我不知道彩虹有多少种颜色。

八年级数学试卷易错压轴选择题精选:平行四边形选择题练习题(附答案)100(2)

八年级数学试卷易错压轴选择题精选:平行四边形选择题练习题(附答案)100(2)

八年级数学试卷易错压轴选择题精选:平行四边形选择题练习题(附答案)100(2)一、易错压轴选择题精选:平行四边形选择题1.如图,在正方形ABCD中,E为BC上一点,过点E作EF∥CD,交AD于F,交对角线BD于G,取DG的中点H,连结AH,EH,FH.下列结论:①∠EFH=45°;②△AHD≌△EHF;③∠AEF+∠HAD=45°;④若BEEC=2,则1113=BEHAHESS.其中结论正确的是()A.①②③B.①②④C.②③④D.①②③④2.如图,矩形ABCD的面积为20cm2,对角线相交于点O.以AB、AO为邻边画平行四边形AOC1B,对角线相交于点O ;以AB、AO 为邻边画平行四边形AO1C2B,对角线相交于点O2 :……以此类推,则平行四边形AO4C5B的面积为()A.58cm2B.54cm2C.516cm2D.532cm23.如图,正方形ABCD的边长为2,Q为CD边上(异于C,D)的一个动点,AQ交BD于点M.过M作MN⊥AQ交BC于点N,作NP⊥BD于点P,连接NQ,下面结论:①AM=MN;②MP=2;③△CNQ的周长为3;④BD+2BP=2BM,其中一定成立的是()A.①②③④B.①②③C.①②④D.①④4.如图,在正方形ABCD中,点E,F分别在BC,CD上,AE AF=,AC与EF相交于点G.下列结论:①AC垂直平分EF;②BE DF EF+=;③当15DAF∠=︒时,AEF 为等边三角形;④当60EAF ∠=︒时,AEB AEF ∠=∠.其中正确的结论是( )A .①③B .②④C .①③④D .②③④5.如图,正方形ABCD 的边长为10,AG=CH=8,BG=DH=6,连接GH ,则线段GH 的长为( )A .2.8B .22C .2.4D .3.56.如图,正方形ABCD 中,在AD 的延长线上取点E ,F ,使DE =AD ,DF =BD ,连接BF 分别交CD ,CE 于H ,G 下列结论:①EC≠2HG ;②∠GDH =∠GHD ;③图中有8个等腰三角形;④CDG DHF S S △△=.其中正确的结论有( )个A .1B .2C .3D .47.将矩形纸片 ABCD 按如图所示的方式折叠,得到菱形 AECF .若 AB =3,则 BC 的长为( )A 2B .2C .1.5D 38.如图所示,四边形ABCD 是边长为1的正方形,E 为BC 边的中点,沿AP 折叠使D 点落在AE 上的点H 处,连接PH 并延长交BC 于点F ,则EF 的长为( )A .5252- B .552- C .353-D .149.如图,点P ,Q 分别是菱形ABCD 的边AD ,BC 上的两个动点,若线段PQ 长的最大值为85 ,最小值为8,则菱形ABCD 的边长为( )A .4 6B .10C .12D .1610.如图,在Rt ABC 中,90ACB ∠=︒,分别以AB ,AC ,BC 为边,在AB 的同侧作正方形ABHI ,ACFG ,BCED .若图中两块阴影部分的面积分别记为1S ,2S ,则对1S ,2S 的大小判断正确的是( )A .12S S >B .12S SC .12S S <D .无法确定11.将矩形纸片ABCD 按如图所示的方式折叠,AE 、EF 为折痕,∠BAE =30°,AB =3 ,折叠后,点C 落在AD 边上的C 1处,并且点B 落在EC 1边上的B 1处.则BC 的长为( )A 3B .3C .2D .312.如图,45A ABC C ∠=∠=∠=︒,E 、F 分别是AB 、BC 的中点,则下列结论:①EF BD ⊥,②12EF BD =,③ADC BEF BFE ∠=∠+∠,④AD DC =,其中正确有( )A .1个B .2个C .3个D .4个13.如图,在一张矩形纸片ABCD 中,4AB =,8BC =,点E ,F 分别在AD , BC 上,将纸片ABCD 沿直线EF 折叠,点C 落在AD 上的一点H 处,点D 落在点G 处,有以下四个结论:①四边形CFHE 是菱形;②EC 平分DCH ∠;③线段BF 的取值范围为34BF ≤≤;④当点H 与点A 重合时,25EF =. 以上结论中,你认为正确的有( )个.A .1B .2C .3D .414.如图,矩形纸片,,ABCD AB a BC b ==,满足12b a b <<,将此矩形纸片按下面顺序折叠,则图4中MN 的长为(用含,a b 的代数式表示)( )A .2b a -B .22b a -C .32b a + D .12b a + 15.如图,平行四边形ABCD 中,对角线AC 、BD 相交于点O ,AD =12AC ,M 、N 、P 分别是OA 、OB 、CD 的中点,下列结论: ①CN ⊥BD ; ②MN =NP ;③四边形MNCP 是菱形; ④ND 平分∠PNM . 其中正确的有( )A .1 个B .2 个C .3 个D .4 个16.如图,ABCD 中,点E 是AD 上一点,BE ⊥AB ,△ABE 沿BE 对折得到△BEG ,过点D 作DF ∥EG 交BC 于点F ,△DFC 沿DF 对折,点C 恰好与点G 重合,则ABAD的值为( )A .12B .33C .22D .3217.如图,在ABC 中,AB =AC =6,∠B =45°,D 是BC 上一个动点,连接AD ,以AD 为边向右侧作等腰ADE ,其中AD =AE ,∠ADE =45°,连接CE .在点D 从点B 向点C 运动过程中,CDE △周长的最小值是( )A .62B .626+C .92D .926+18.在ABCF 中,2BC AB =,CD AB ⊥于点D ,点E 为AF 的中点,若50ADE ∠=︒,则B 的度数是( )A .50︒B .60︒C .70︒D .80︒19.如图,直角梯形ABCD 中AD ∥BC ,∠D =90°.∠A 的平分线交DC 于E ,EF ⊥AB 于F .已知AD =3.5cm ,DC =4cm ,BC =6.5cm .那么四边形BCEF 的周长是( )A .10cmB .11cmC .11.5cmD .12cm20.如图,在平行四边形ABCD 中,过点A 作AG BC ⊥于G ,作AH CD ⊥于H ,且45GAH ∠=︒,2AG =,3AH =,则平行四边形的面积是( )A .62B .122C .6D .1221.如图,在ABCD 中,2,AB AD F =是CD 的中点,作BE AD ⊥于点E ,连接EF BF 、,下列结论:①CBF ABF ∠=∠;②FE FB =;③2EFB S S ∆=四边形DEBC ;④3BFE DEF ∠=∠;其中正确的个数是( )A .1B .2C .3D .422.如图,在□ABCD 中,AD=2AB ,F 是AD 的中点,作CE ⊥AB ,垂足E 在线段AB 上,连接EF 、CF ,则下列结论:(1)∠DCF=12∠BCD ;(2)EF=CF ;(3)S △BEC = 2S △CEF ;(4)∠DFE=3∠AEF ;其中正确的结论是( )A .(1)(2)B .(1)(2)(4)C .(2)(3)(4)D .(1)(3)(4)23.如图,在平行四边形ABCD 中,AE 平分BAD ∠,交BC 于点E 且AB AE =,延长AB 与DE 的延长线相交于点F ,连接AC 、CF .下列结论:①ABC EAD △≌△;②ABE △是等边三角形;③BF AD =;④BEF ABC S S =△△;⑤CEF ABE S S =△△;其中正确的有( )A.2个B.3个C.4个D.5个24.如图,已知△ABC的面积为12,点D在线段AC上,点F在线段BC的延长线上,且BF=4CF,四边形DCFE是平行四边形,则图中阴影部分的面积为()A.2 B.3 C.4 D.525.如图,将边长为8cm的正方形ABCD折叠,使点D落在BC边的中点E处,点A落在点F处,折痕为MN,则折痕MN的长是()A.53cm B.55cm C.46cm D.45cm26.如图,在△ABC中,∠ABC和∠ACB的角平分线相交于点O.过点O作EF∥BC交AB 于E.交AC于F.过点O作OD⊥AC于D.下列五个结论:其中正确的有()(1) EF=BE+CF;(2)∠BOC=90°+12∠A;(3)点O到△ABC各边的距离都相等;(4)设OD=m.若AE十AF =n,则S△AEF= mn;(5)S△AEF=S△FOC.A.2个B.3个C.4个D.5个27.如图,点,,A B E在同一条直线上,正方形ABCD、正方形BEFC的边长分别为23,、H为线段DF的中点,则BH的长为()A .21B .26C .33D .29 28.如图,正方形ABCD 中,AB=12,点E 在边CD 上,且BG=CG ,将△ADE 沿AE 对折至△AFE,延长EF 交边BC 于点G ,连接AG 、CF ,下列结论:①△ABG≌△AFG;②∠EAG=45°;③CE=2DE;④AG∥CF;⑤S △FGC =725.其中正确结论的个数是( )A .2个B .3个C .4个D .5个29.如图,点O (0,0),A (0,1)是正方形1OAA B 的两个顶点,以1OA 对角线为边作正方形121OA A B ,再以正方形的对角线2OA 作正方形121OA A B ,…,依此规律,则点8A 的坐标是( )A .(-8,0)B .(0,8)C .(0,2)D .(0,16)30.如图,在△ABC 中,AB =3,AC =4,BC =5,△ABD ,△ACE ,△BCF 都是等边三角形,下列结论中:①AB ⊥AC ;②四边形AEFD 是平行四边形;③∠DFE =150°;④S 四边形AEFD =5.正确的个数是( )A .1个B .2个C .3个D .4个【参考答案】***试卷处理标记,请不要删除一、易错压轴选择题精选:平行四边形选择题 1.A 【分析】①根据正方形的性质证明∠ADB =45°,进而得△DFG 为等腰直角三角形,根据等腰三角形的三线合一性质得∠EFH =12∠EFD =45°,故①正确; ②根据矩形性质得AF =EB ,∠BEF =90°,再证明△AFH ≌△EGH 得EH =AH ,进而证明△EHF ≌△AHD ,故②正确;③由△EHF ≌△AHD 得∠EHF =∠AHD ,怀AH =EH 得∠AEF +∠HEF =45°,进而得∠AEF +∠HAD =45°,故③正确;④如图,过点H 作MN ⊥AD 于点M ,与BC 交于点N ,设EC =FD =FG =x ,则BE =AF =EG =2x ,BC =DC =AB =AD =3x ,HM =12x ,AM =52x ,HN =52x ,由勾股定理得AH 2,再由三角形的面积公式得BEH AHESS,便可判断④的正误.【详解】证明:①在正方形ABCD 中,∠ADC =∠C =90°,∠ADB =45°, ∵EF ∥CD , ∴∠EFD =90°, ∴四边形EFDC 是矩形. 在Rt △FDG 中,∠FDG =45°,∴FD=FG,∵H是DG中点,∴∠EFH=12∠EFD=45°故①正确;②∵四边形ABEF是矩形,∴AF=EB,∠BEF=90°,∵BD平分∠ABC,∴∠EBG=∠EGB=45°,∴BE=GE,∴AF=EG.在Rt△FGD中,H是DG的中点,∴FH=GH,FH⊥BD,∵∠AFH=∠AFE+∠GFH=90°+45°=135°,∠EGH=180°﹣∠EGB=180°﹣45°=135°,∴∠AFH=∠EGH,∴△AFH≌△EGH(SAS),∴EH=AH,∵EF=AD,FH=DH,∴△EHF≌△AHD(SSS),故②正确;③∵△EHF≌△AHD,∴∠EHF=∠AHD,∴∠AHE=∠DHF=90°,∵AH=EH,∴∠AEH=45°,即∠AEF+∠HEF=45°,∵∠HEF=∠HAD,∴∠AEF+∠HAD=45°,故③正确;④如图,过点H作MN⊥AD于点M,与BC交于点N,设EC=FD=FG=x,则BE=AF=EG=2x,∴BC =DC =AB =AD =3x ,HM =12x ,AM =52x ,HN =52x , ∴22225113222AH x x x ⎛⎫⎛⎫+= ⎪ ⎪⎝⎭⎝⎭=, ∴211021132BEH AHE BE HN S =S AH ⋅=, 故④错误;故选:A .【点睛】本题主要考查正方形的性质、矩形的性质、等腰三角形的性质及勾股定理,这是一道几何综合型题,关键是根据正方形的性质得到线段的等量关系,然后利用矩形、等腰三角形的性质进行求解即可.2.A【分析】设矩形ABCD 的面积为S=20cm 2,由O 为矩形ABCD 的对角线的交点,可得平行四边形AOC 1B 底边AB 上的高等于BC 的12,依此类推可得下一个图形的面积是上一个图形的面积的12,然后求解即可. 【详解】 设矩形ABCD 的面积为S=20cm 2,∵O 为矩形ABCD 的对角线的交点,∴平行四边形AOC 1B 底边AB 上的高等于BC 的12, ∴平行四边形AOC 1B 的面积=12S , ∵平行四边形AOC 1B 的对角线交于点O 1,∴平行四边形AO 1C 2B 的边AB 上的高等于平行四边形AOC 1B 底边AB 上的高的12, ∴平行四边形AO 1C 2B 的面积=12×12S=22S , ……依此类推,平行四边形AO 4C 5B 的面积=52S =5202=58(cm 2), 故选:A .【点睛】本题考查了矩形的对角线互相平分,平行四边形的对角线互相平分的性质,得到下一个图形的面积是上一个图形的面积的12是解题的关键.3.C【分析】连接AC交BD于O,作ME⊥AB于E,MF⊥BC于F,延长CB到H,使得BH=DQ.①正确.只要证明△AME≌△NMF即可;②正确.只要证明△AOM≌△MPN即可;③错误.只要证明∠ADQ≌△ABH,由此推出△ANQ≌△ANH即可;④正确.只要证明△AME≌△NMF,证得四边形EMFB是正方形即可解决问题;【详解】连接AC交BD于O,作ME⊥AB于E,MF⊥BC于F,延长CB到H,使得BH=DQ.∵四边形ABCD是正方形,∴AC⊥BD,222,∠DBA=∠DBC=45°,∴ME=MF,∵∠MEB=∠MFB=∠EBF=90°,∴四边形EMFB是矩形,∵ME=MF,∴四边形EMFB是正方形,∴∠EMF=∠AMN=90°,∴∠AME=∠NMF,∵∠AEM=∠MFN=90°,∴△AME≌△NMF(ASA),∴AM=MN,故①正确;∵∠OAM+∠AMO=90°,∠AMO+∠NMP=90°,∴∠AMO=∠MNP,∵∠AOM=∠NPM=90°,∴△AOM≌△MPN(AAS),∴2,故②正确;∵DQ=BH,AD=AB,∠ADQ=∠ABH=90°,∴∠ADQ ≌△ABH (SAS ),∴AQ=AH ,∠QAD=∠BAH ,∴∠BAH+∠BAQ=∠DAQ+∠BAQ=90°,∵AM=MN ,∠AMN=90°,∴∠MAN=45°,∴∠NAQ=∠NAH=45°,∴△ANQ ≌△ANH (SAS ),∴NQ=NH=BN+BH=BN+DQ ,∴△CNQ 的周长=CN+CQ+BN+DQ=4,故③错误;∵BD+2BP=2BO+2BP=2AO+2BP=2PM+2BP ,∴BD+2BP=2BM ,故④正确.故选:C .【点睛】本题考查了正方形的性质,全等三角形的判定和性质,等腰直角三角形的判定和性质等知识,解题的关键是学会添加常用辅助线,构造全等三角形解决问题.4.A【分析】①通过条件可以得出△ABE ≌△ADF ,从而得出∠BAE=∠DAF ,BE=DF ,由正方形的性质就可以得出EC=FC ,就可以得出AC 垂直平分EF ,②设BC=x ,CE=y ,由勾股定理就可以得出EF 与x 、y 的关系,表示出BE 与EF ,即可判断BE+DF 与EF 关系不确定;③当∠DAF=15°时,可计算出∠EAF=60°,即可判断△EAF 为等边三角形,④当∠EAF=60°时,可证明△AEF 是等边三角形,从而可得∠AEF=60°,而△CEF 是等腰直角三角形,得∠CEF=45°,从而可求出∠AEB=75°,进而可得结论.【详解】解:①四边形ABCD 是正方形,∴AB ═AD ,∠B=∠D=90°.在Rt △ABE 和Rt △ADF 中,AE AF AB AD ⎧⎨⎩==, ∴Rt △ABE ≌Rt △ADF (HL ),∴BE=DF∵BC=CD ,∴BC-BE=CD-DF ,即CE=CF ,∵AE=AF ,∴AC 垂直平分EF .(故①正确).②设BC=a ,CE=y ,∴BE+DF=2(a-y )EF=y ,∴BE+DF与EF关系不确定,只有当y=(2−2)a时成立,(故②错误).③当∠DAF=15°时,∵Rt△ABE≌Rt△ADF,∴∠DAF=∠BAE=15°,∴∠EAF=90°-2×15°=60°,又∵AE=AF∴△AEF为等边三角形.(故③正确).④当∠EAF=60°时,由①知AE=AF,∴△AEF是等边三角形,∴∠AEF=60°,又△CEF为等腰直角三角形,∴∠CEF=45°∴∠AEB=180°-∠AEF-∠CEF=75°,∴∠AEB≠∠AEF,故④错误.综上所述,正确的有①③,故选:A.【点睛】本题考查了正方形的性质的运用,全等三角形的判定及性质的运用,勾股定理的运用,等边三角形的性质的运用,三角形的面积公式的运用,解答本题时运用勾股定理的性质解题时关键.5.B【分析】延长BG交CH于点E,根据正方形的性质证明△ABG≌△CDH≌△BCE,可得GE=BE-BG=2,HE=CH-CE=2,∠HEG=90°,从而由勾股定理可得GH的长.【详解】解:如图,延长BG交CH于点E,∵四边形ABCD是正方形,∴∠ABC=90°,AB=CD=10,∵AG=8,BG=6,∴AG2+BG2=AB2,∴∠AGB=90°,∴∠1+∠2=90°,又∵∠2+∠3=90°,∴∠1=∠3,同理:∠4=∠6,在△ABG和△CDH中,AB=CD=10AG=CH=8BG=DH=6∴△ABG≌△CDH(SSS),∴∠1=∠5,∠2=∠6,∴∠2=∠4,在△ABG和△BCE中,∵∠1=∠3,AB=BC,∠2=∠4,∴△ABG≌△BCE(ASA),∴BE=AG=8,CE=BG=6,∠BEC=∠AGB=90°,∴GE=BE-BG=8-6=2,同理可得HE=2,在Rt△GHE中,GH===故选:B.【点睛】本题主要考查正方形的性质、全等三角形的判定与性质、勾股定理及其逆定理的综合运用,通过证三角形全等得出△GHE为直角三角形且能够求出两条直角边的长是解题的关键.6.B【分析】关键结合图形证明△CHG≌△EGD,即可逐项判断求解【详解】解:∵DF=BD,∴∠DFB=∠DBF,∵AD∥BC,DE=BC,∴四边形DBCE是平行四边形,∠DFB=∠GBC,∴∠DEC=∠DBC=45°,∴∠DEC=2∠EFB,∴∠EFB=22.5°,∠CGB=∠CBG=22.5°,∴CG=BC=DE,∵DE=DC,∴∠DEG=∠DCE,∵∠GHC=∠CDF+∠DFB=90°+22.5°=112.5°,∠DGE=180°-(∠BGD+∠EGF),=180°-(∠BGD+∠BGC),=180°-(180°-∠DCG )÷2,=180°-(180°-45°)÷2,=112.5°,∴∠GHC=∠DGE ,∴△CHG ≌△EGD ,∴∠EDG=∠CGB=∠CBF ,∴∠GDH=90°-∠EDG ,∠GHD=∠BHC=90°-∠CGB ,∴∠GDH=∠GHD故②正确;∴∠GDH=∠GHD又∠EFB=22.5°,∴∠DHG=∠GDH=67.5°∴∠GDF=90°-∠GDH=22.5°=∠EFB,∴DG=GF,∴HG=DG=GF∴HF=2HG,显然CE≠HF=2HG,故①正确;∵△CHG ≌△EGD ,∴CHG EGD S S ∆∆=∴CHG DHG EGD DHG S S S S ∆∆∆∆+=+,即CDG DHGE S S △四边形=而=EFG DHGE DHF S S S ∆+四边形△,故CDG DHF S S ≠△△故④不正确;结合前面条件易知等腰三角形有△ABD ,△CDB ,△BDF ,△CDE ,△BCG ,△DGH ,△EGF ,△CDG ,△DGF 共9个,∴③错误;故正确的有①②,有2个,故选:B【点睛】本题主要考查对三角形的内角和定理,全等三角形的判定和性质,等腰三角形的性质和判定,正方形的性质,等知识点的理解和掌握,综合运用这些性质进行推理是解此题的关键.7.D【分析】设BC x =,先根据矩形的性质可得90,B AD BC ∠=︒=,再根据折叠的性质可得,,90OA AD x OC BC x COE B ====∠=∠=︒,从而可得OA OC =,又根据菱形的性质可得AE CE =,然后根据三角形全等的判定定理与性质可得90AOE COE ∠=∠=︒,从而可得点,,A O C 共线,由此可得2AC x =,最后在Rt ABC 中,利用勾股定理即可得.【详解】设BC x =,四边形ABCD 是矩形,90,B AD BC x ∴∠=︒==,由折叠的性质得:,,90OA AD x OC BC x COE B ====∠=∠=︒,OA OC x ∴==,四边形AECF 是菱形,AE CE ∴=,在AOE △和COE 中,OA OC AE CE OE OE =⎧⎪=⎨⎪=⎩,()AOE COE SSS ∴≅,90AOE COE ∴∠=∠=︒,即180AOE COE ∠+∠=︒,∴点,,A O C 共线,2AC OA OC x ∴=+=,在Rt ABC 中,222AB BC AC +=,即2223(2)x x +=,解得x =x =即BC =故选:D . 【点睛】本题考查了矩形与菱形的性质、折叠的性质、三角形全等的判定定理与性质、勾股定理等知识点,利用三角形全等的判定定理与性质证出90AOE COE ∠=∠=︒,从而得出点,,A O C 共线是解题关键.8.A【分析】首先证明Rt △AFB ≌Rt △AFH ,推出BF=FH ,设EF=x ,则BF=FH=12x -,在Rt △FEH 中,根据222,EF EH FH =+构建方程即可解决问题;【详解】解:连接AF .∵四边形ABCD 是正方形, ∴AD=BC=1,∠B=90°,∵BE=EC=12, ∴225AB BE += 由翻折不变性可知:AD=AH=AB=1,∴EH=512-, ∵∠B=∠AHF=90°,AF=AF ,AH=AB ,∴Rt △AFB ≌Rt △AFH ,∴BF=FH ,设EF=x ,则BF=FH=12x -, 在Rt △FEH 中,∵222,EF EH FH =+ ∴22215()1),2x x =-+ ∴525x -= 故选:A .【点睛】本题考查翻折变换、正方形的性质、全等三角形的判定和性质、勾股定理等知识,解题的关键是准确寻找全等三角形解决问题,学会利用参数构建方程解决问题,9.B【分析】当点P 和点A 重合时,当点C 和点Q 重合时,PQ 的值最大,当PQ ⊥BC 时,PQ 的值最小,利用这两组数据,在Rt△ABQ 中,可求得答案.【详解】当点P 和点A 重合时,当点C 和点Q 重合时,PQ 的值最大,85PQ =当PQ⊥BC时,PQ的值最小,∴PQ=8,∠Q=90°,在Rt△ACQ中,()22CQ=-=85816.在Rt△ABQ中,设AB=BC=x,则BQ=16-x,∴AQ2+BQ2=AB2即82+(16-x)2=x2解之:x=10.故答案为:B.【点睛】本题考查菱形的性质和勾股定理的运用,解题关键是根据菱形的性质,判断出PQ最大和最小的情况.10.B【分析】连接EH,过点H作HK⊥BF于点K,令AE与BH交于点J,HL与BF交于点L,根据已知条件易证△BHK≌△ABC,继而由全等三角形的性质得S△BHK=S△ABC,BC=HK,∠ABC=∠BHK,再由全等三角形的判定可得△BCJ≌△HKL,进而可得S1=S△BHK=S△ABC,由正方形的性质和全等三角形的判定可知△ABC≌△AIG,继而可得S△ABC=S△AIG=S2,等量代换即可求解.【详解】解:连接EH,过点H作HK⊥BF于点K,令AE与BH交于点J,HL与BF交于点L,由题意可知:四边形BCED是正方形,四边形ACFG是正方形,四边形ABHI是正方形,∠ACB=90°∴∠CEH=∠ECK=90° ,CE=BC∵∠BKH=90°,∴四边形CEHK是矩形,∴ CE=HK又∠HBK+∠ABC=90°, ∠BAC+∠ABC=90°∴∠HBK=∠BAC∴△BHK≌△ABC(AAS)∴S△BHK=S△ABC,BC=HK,∠ABC=∠BHK,∵∠ABC+∠CBJ=90°,∠BHK+∠KHL=90°∴∠CBJ=∠KHL∴△BCJ≌△HKL(ASA)∴S△BCJ=S△HKL,∴S1=S△BHK=S△ABC,∵四边形ACFG是正方形,四边形ABHI是正方形,∴AB=AI,AC=AG,∠G=∠ACB=90°∴△ABC≌△AIG(SAS)∴S△ABC=S△AIG=S2,即S1=S2故选:B【点睛】本题主要考查正方形的性质,全等三角形的判定及其性质,解题的关键是熟练掌握正方形的性质及全等三角形的判定方法.11.B【解析】试题分析:由三角函数易得BE,AE长,根据翻折和对边平行可得△AEC1和△CEC1为等边三角形,那么就得到EC长,相加即可.解:连接CC1.在Rt△ABE中,∠BAE=30°,AB3∴BE=AB×tan30°=1,AE=2,∠AEB1=∠AEB=60°,∵四边形ABCD是矩形∴AD∥BC,∴∠C1AE=∠AEB=60°,∴△AEC1为等边三角形,同理△CC1E也为等边三角形,∴EC=EC1=AE=2,∴BC=BE+EC=3,故选B.12.C【分析】根据三角形的中位线定理“三角形的中位线平行于第三边”可得//EF AC ,12EF AC =,再由45°角可证△ABQ 为等腰直角三角形,从而可得可得AQ BQ =,进而证明AQC BQDASA ≅△△(),利用三角形的全等性质求解即可. 【详解】解:如图所示:连接AC ,延长BD 交AC 于点M ,延长AD 交BC 于Q ,延长CD 交AB 于P .45ABC C ∠=∠=︒,CP AB ∴⊥,45ABC BAD ∠=∠=︒,AQ BC ∴⊥,点D 为两条高的交点,BM ∴为AC 边上的高,即:BM AC ⊥,由中位线定理可得//EF AC ,12EF AC =, BD EF ∴⊥,故①正确;45DBQ DCA ∠+∠=︒,45DCA CAQ ∠+∠=︒,DBQ CAQ ∴∠=∠,BAD ABC ∠=∠,AQ BQ ∴=,90BQD AQC ∠=∠=︒,∴根据以上条件得AQC BQD ASA ≅△△(),BD AC ∴=,12EF AC ∴=,故②正确; 45A ABC C ∠=∠=∠=︒,()18045DAC DCA BAD ABC BCD ∴∠+∠=︒-∠+∠+∠=︒,180135()180ADC DAC DCA BEF BFE ABC ∴∠=︒-∠+∠=︒=∠+∠=︒-∠,故③ADC BEF BFE ∠=∠+∠成立;无法证明AD CD =,故④错误.综上所述:正确的是①②③,故选C .【点睛】本题考点在于三角形的中位线和三角形全等的判断及应用.解题关键是证明AQC BQD ASA ≅△△().13.C【分析】①先判断出四边形CFHE 是平行四边形,再根据翻折的性质可得CF=FH ,然后根据邻边相等的平行四边形是菱形证明,判断出①正确;②根据菱形的对角线平分一组对角线可得∠BCH=∠ECH ,然后求出只有∠DCE=30°时EC 平分∠DCH ,判断出②错误;③点H 与点A 重合时,设BF=x ,表示出AF=FC=8-x ,利用勾股定理列出方程求解得到BF 的最小值,点G 与点D 重合时,CF=CD ,求出最大值BF=4,然后写出BF 的取值范围,判断出③正确;④过点F 作FM ⊥AD 于M ,求出ME ,再利用勾股定理列式求解得到EF ,判断出④正确.【详解】解:①∵FH 与CG ,EH 与CF 都是矩形ABCD 的对边AD 、BC 的一部分,∴FH ∥CG ,EH ∥CF ,∴四边形CFHE 是平行四边形,由翻折的性质得,CF=FH ,∴四边形CFHE 是菱形,(故①正确);②∴∠BCH=∠ECH ,∴只有∠DCE=30°时EC 平分∠DCH ,(故②错误);③点H 与点A 重合时,此时BF 最小,设BF=x ,则AF=FC=8-x ,在Rt △ABF 中,AB 2+BF 2=AF 2,即42+x 2=(8-x )2,解得x=3,点G 与点D 重合时,此时BF 最大,CF=CD=4,∴BF=4,∴线段BF 的取值范围为3≤BF ≤4,(故③正确);过点F 作FM ⊥AD 于M ,则ME=(8-3)-3=2,由勾股定理得, EF=22MF ME +=2242+=25,(故④正确);综上所述,结论正确的有①③④共3个,故选C .【点睛】本题考查了翻折变换的性质,菱形的判定与性质,勾股定理的应用,难点在于灵活运用菱形的判定与性质与勾股定理等其它知识有机结合.14.B【分析】如图3中,由折叠的性质可得PQ =BC =b ,A 1F =a ﹣12b ,△PEQ 是等腰直角三角形,进而可得△MNE 是等腰直角三角形,然后根据等腰直角三角形的性质可得EG =12MN ,而12EG EF A F =-,进一步即可求得答案.【详解】解:如图3中,由折叠的性质可得PQ =BC =b ,A 1F =a ﹣12b ,∠EPQ =11904522APQ ∠=⨯︒=︒,∠EQP =11904522DQP ∠=⨯︒=︒, ∴∠PEQ =90°,∴△PEQ 是等腰直角三角形,如图4,∵MN ∥PQ ,∴△MNE 是等腰直角三角形,∵EG ⊥MN ,∴EG=MG=NG =12MN , ∵12EG EF A F =-=a ﹣2(a ﹣12b )=b ﹣a , ∴MN =2EG =22b a -.故选:B .【点睛】本题考查了矩形的性质、折叠的性质以及等腰直角三角形的判定与性质,正确理解题意、熟练掌握等腰直角三角形的判定和性质是解题的关键.15.C【分析】证出OC=BC,由等腰三角形的性质得CN⊥BD,①正确;证出MN是△AOB的中位线,得MN∥AB,MN=12AB,由直角三角形的性质得NP=12CD,则MN=NP,②正确;周长四边形MNCP是平行四边形,无法证明四边形MNCP是菱形;③错误;由平行线的性质和等腰三角形的性质证出∠MND=∠PND,则ND平分∠PNM,④正确;即可得出结论.【详解】解:∵四边形ABCD是平行四边形,∴AB=CD,AB∥CD,BC=AD,OA=OC=12 AC,∵AD=12 AC,∴OC=BC,∵N是OB的中点,∴CN⊥BD,①正确;∵M、N分别是OA、OB的中点,∴MN是△AOB的中位线,∴MN∥AB,MN=12 AB,∵CN⊥BD,∴∠CND=90°,∵P是CD的中点,∴NP=12CD=PD=PC,∴MN=NP,②正确;∵MN∥AB,AB∥CD,∴MN∥CD,又∵NP=PC,MN=NP,∴MN=PC,∴四边形MNCP是平行四边形,无法证明四边形MNCP是菱形;③错误;∵MN∥CD,∴∠PDN=∠MND,∵NP=PD,∴∠PDN=∠PND,∴∠MND=∠PND,∴ND平分∠PNM,④正确;正确的个数有3个,故选:C.本题考查了平行四边形性质和判定,三角形中位线定理,直角三角形斜边上的中线性质,等腰三角形的性质等;熟练掌握三角形中位线定理、等腰三角形的性质、直角三角形斜边上的中线性质是解题的关键.16.B【分析】根据平行线的性质和轴对称的性质,利用SAS 证明BEG DEG ≅,进而得到ADG 90∠=︒,设AB=x ,则AG=2x ,CD=x ,,即可求解.【详解】解:在ABCD 中∵DF ∥EG∴∠DEG=∠DFB∵△ABE 沿BE 对折得到△BEG∴∠DEG =2∠A∵∠DFB =∠C +∠CDF∠A=∠C∴∠CDF=∠A∵△DFC 沿DF 对折∴∠BGE=∠DGEBG=DGEG=EG∴BEG DEG ≅∵BE⊥AB∴ADG 90∠=︒设AB=x ,则AG=2x ,CD=x ,=∴3AB AD == 故选:B .【点睛】此题主要考查平行线的性质、轴对称的性质、全等三角形的判断和性质、勾股定理,熟练运用平行线的性质和轴对称的性质证明BEG DEG ≅是解题关键.17.B【分析】 如图(见解析),先根据等腰直角三角形的判定与性质可得90,BAC DAE BC DE ∠=∠=︒==,再根据三角形全等的判定定理与性质可得BD CE =,从而可得CDE △周长为BC +,然后根据垂线段最短可求出AD 的最小值,由此即可得.在ABC 中,6,45AB AC B ==∠=︒,ABC ∴是等腰直角三角形,2290,62BAC BC AB AC ∠=︒=+=,在ADE 中,,45AD AE ADE =∠=︒,ADE ∴是等腰直角三角形,2290,2DAE DE AD AE AD ∠=︒=+=,90BAD CAD CAE CAD ∴∠+∠=∠+∠=︒,BAD CAE ∴∠=∠,在ABD △和ACE △中,AB AC BAD CAE AD AE =⎧⎪∠=∠⎨⎪=⎩,()ABD ACE SAS ∴≅,BD CE ∴=,CDE ∴周长为622CD CE DE CD BD DE BC DE AD ++=++=+=+, 则当AD 取得最小值时,CDE △的周长最小,由垂线段最短可知,当AD BC ⊥时,AD 取得最小值,AD ∴是BC 边上的中线(等腰三角形的三线合一),1322AD BC ∴==(直角三角形斜边上的中线等于斜边的一半), CDE ∴周长的最小值为62232626+⨯=+,故选:B .【点睛】本题考查了等腰直角三角形的判定与性质、直角三角形斜边上的中线、三角形全等的判定定理与性质、垂线段最短等知识点,正确找出两个全等三角形是解题关键.18.D【分析】连结CE ,并延长CE ,交BA 的延长线于点N ,根据已知条件和平行四边形的性质可证明△NAE ≌△CFE ,所以NE =CE ,NA =CF ,再由已知条件CD ⊥AB 于D ,∠ADE =50°,即可求出∠B 的度数.【详解】解:连结CE ,并延长CE ,交BA 的延长线于点N ,∵四边形ABCF 是平行四边形,∴AB ∥CF ,AB =CF ,∴∠NAE =∠F ,∵点E 是的AF 中点,∴AE =FE ,在△NAE 和△CFE 中,NAE F AE FEAEN FEC ∠=∠⎧⎪=⎨⎪∠=∠⎩, ∴△NAE ≌△CFE (ASA ),∴NE =CE ,NA =CF ,∵AB =CF ,∴NA =AB ,即BN =2AB ,∵BC =2AB ,∴BC =BN ,∠N =∠NCB ,∵CD ⊥AB 于D ,即∠NDC =90°且NE =CE ,∴DE =12NC =NE , ∴∠N =∠NDE =50°=∠NCB ,∴∠B =80°.故选:D .【点睛】本题考查了平行四边形的性质,综合性较强,难度较大,解答本题的关键是正确作出辅助线,构造全等三角形,在利用等腰三角形的性质解答.19.D【分析】根据角平分线性质得出AD=AF ,根据勾股定理求出EF=DC ,求出AB 长,求出BE ,即可求出答案.【详解】∵AE 平分∠DAB ,∠D=90°,EF ⊥AB ,∴AF=AD=3.5cm ,EF=DE ,∴DC=CE+DE=CE+EF=4cm ,过A 作AM ⊥BC 于M ,则四边形AMCD 是矩形,∴AM=DC=4cm ,AD=CM=3.5cm ,∵BC=6.5cm ,∴BM=6.5cm-3.5cm=3cm ,在Rt △AMB 中,由勾股定理得:22435AB(cm ),∴BF=AB-AF=5cm-3.5cm=1.5cm ,∴四边形BCEF 的周长是BC+BF+CE+EF=6.5cm+1.5cm+CD=8cm+4cm=12cm ,故选:D .【点睛】本题考查了勾股定理,矩形的性质和判定,角平分线性质等知识点,能求出各个边的长度是解此题的关键.20.A【分析】设B x ∠=,先根据平行四边形的性质可得,180,D B x BAD x AB CD ∠=∠=∠=︒-=,再根据直角三角形的两锐角互余、角的和差可得45x =︒,然后根据等腰直角三角形的判定与性质、勾股定理可得22AB =22CD =,最后利用平行四边形的面积公式即可得.【详解】设B x ∠=,四边形ABCD 是平行四边形, ,180180,D B x BAD B x AB CD ∴∠=∠=∠=︒-∠=︒-=,,AG BC AH CD ⊥⊥,9090,9090BAG B x DAH D x ∴∠=︒-∠=︒-∠=︒-∠=︒-,又180,45BAG DAH BAD GAH x GAH ∠+︒-∠+∠=∠∠=︒=,909100458x x x ︒-+︒-=∴︒+︒-,解得45x =︒,即45B ∠=︒,Rt ABG ∴是等腰直角三角形,222,22BG AG AB AG BG ∴===+=22CD ∴=,∴平行四边形ABCD 的面积是3AH CD ⋅=⨯=,故选:A .【点睛】本题考查了平行四边形的性质、直角三角形的两锐角互余、等腰直角三角形的判定与性质、勾股定理等知识点,熟练掌握平行四边形的性质是解题关键.21.C【分析】由平行四边形的性质结合AB=2AD ,CD=2CF 可得CF=CB ,从而可得∠CBF=∠CFB ,再根据CD ∥AB ,得∠CFB=∠ABF ,继而可得CBF ABF ∠=∠,可以判断①正确;延长EF 交BC 的延长线与M ,证明△DFE 与△CFM(AAS),继而得EF=FM=12EM ,证明∠CBE=∠AEB=90°,然后根据直角三角形斜边中线的性质即可判断②正确;由上可得S △BEF =S △BMF ,S △DFE =S △CFM ,继而可得S △EBF =S △BMF =S △EDF +S △FBC ,继而可得2EFB S S ∆=四边形DEBC ,可判断③正确;过点F 作FN ⊥BE ,垂足为N ,则∠FNE=90°,则可得AD//FN ,则有∠DEF=∠EFN ,根据等腰三角形的性质可得∠BFE=2∠EFN ,继而得∠BFE=2∠DEF ,判断④错误.【详解】∵四边形ABCD 是平行四边形,∴AD=BC ,AB=CD ,AD//BC ,∵AB=2AD ,CD=2CF ,∴CF=CB ,∴∠CBF=∠CFB ,∵CD ∥AB ,∴∠CFB=∠ABF ,∴CBF ABF ∠=∠,故①正确;延长EF 交BC 的延长线与M ,∵AD//BC ,∴∠DEF=∠M ,又∵∠DFE=∠CFM ,DF=CF ,∴△DFE 与△CFM(AAS),∴EF=FM=12EM , ∵BF ⊥AD ,∴∠AEB=90°,∵在平行四边形ABCD 中,AD ∥BC ,∴∠CBE=∠AEB=90°,∴BF=12EM , ∴BF=EF ,故②正确;∵EF=FM ,∴S △BEF =S △BMF ,∵△DFE ≌△CFM ,∴S △DFE =S △CFM ,∴S △EBF =S △BMF =S △EDF +S △FBC ,∴2EFB S S ∆=四边形DEBC ,故③正确;过点F 作FN ⊥BE ,垂足为N ,则∠FNE=90°,∴∠AEB=∠FEN ,∴AD//EF ,∴∠DEF=∠EFN ,又∵EF=FB ,∴∠BFE=2∠EFN ,∴∠BFE=2∠DEF ,故④错误,所以正确的有3个,故选C.【点睛】本题考查了平行四边形的性质,直角三角形斜边中线的性质,等腰三角形的判断与性质等,综合性较强,有一定的难度,正确添加辅助线,熟练掌握和灵活运用相关知识是解题的关键.22.B【分析】利用平行四边形的性质:平行四边形的对边相等且平行,再由全等三角形的判定得出△AEF ≌△DMF (ASA ),利用全等三角形的性质得出对应线段之间关系进而得出答案.【详解】(1)∵F 是AD 的中点,∴AF=FD ,∵在▱ABCD 中,AD=2AB ,∴AF=FD=CD ,∴∠DFC=∠DCF ,∵AD ∥BC ,∴∠DFC=∠FCB ,∴∠DCF=∠BCF ,∴∠DCF=12∠BCD ,故正确;(2)延长EF ,交CD 延长线于M ,∵四边形ABCD 是平行四边形,∴AB ∥CD ,∴∠A=∠MDF ,∵F 为AD 中点,∴AF=FD ,在△AEF 和△DFM 中,A FDM AF DFAFE DFM ∠∠⎧⎪⎨⎪∠∠⎩===, ∴△AEF ≌△DMF (ASA ),∴FE=MF ,∠AEF=∠M ,∵CE ⊥AB ,∴∠AEC=90°,∴∠AEC=∠ECD=90°,∵FM=EF ,∴EF=CF ,故正确;(3)∵EF=FM ,∴S △EFC =S △CFM ,∵MC >BE ,∴S △BEC <2S △EFC故S △BEC =2S △CEF 错误;(4)设∠FEC=x ,则∠FCE=x ,∴∠DCF=∠DFC=90°-x ,∴∠EFC=180°-2x ,∴∠EFD=90°-x+180°-2x=270°-3x ,∵∠AEF=90°-x ,∴∠DFE=3∠AEF ,故正确,故选:B .【点睛】此题主要考查了平行四边形的性质以及全等三角形的判定与性质等知识,解决本题的关键是得出△AEF ≌△DME .23.B【分析】由平行四边形的性质和角平分线的定义得出∠BAE =∠BEA ,得出AB =BE =AE ,得出②正确;由△ABE 是等边三角形得出∠ABE =∠EAD =60°,由SAS 证明△ABC ≌△EAD ,得出①正确;由S △AEC =S △DEC ,S △ABE =S △CEF 得出⑤正确;③和④不正确.【详解】解:∵四边形ABCD 是平行四边形,∴AD ∥BC ,AD =BC ,∴∠EAD =∠AEB ,又∵AE 平分∠BAD ,∴∠BAE =∠DAE ,∴∠BAE =∠BEA ,∴AB =BE ,∵AB =AE ,∴△ABE 是等边三角形;②正确;∴∠ABE =∠EAD =60°,在△ABC 和△EAD 中,AB AE ABE EAD BC AD =⎧⎪∠=∠⎨⎪=⎩,∴△ABC ≌△EAD (SAS );①正确;∵△FCD 与△ABC 等底(AB =CD )等高(AB 与CD 间的距离相等),∴S △FCD =S △ABC ,又∵△AEC 与△DEC 同底等高,∴S △AEC =S △DEC ,∴S △ABE =S △CEF ;⑤正确.若AD 与BF 相等,则BF =BC ,题中未限定这一条件,∴③不一定正确;若S △BEF =S △ACD ;则S △BEF =S △ABC ,则AB =BF ,∴BF =BE ,题中未限定这一条件,∴④不一定正确;正确的有①②⑤.故选:B .【点睛】此题考查了平行四边形的性质、等边三角形的判定与性质、全等三角形的判定与性质、三角形的面积关系;此题比较复杂,注意将每个问题仔细分析.24.C【分析】想办法证明S 阴=S △ADE +S △DEC =S △AEC ,再由EF ∥AC ,可得S △AEC =S △ACF 解决问题.【详解】连接AF 、EC .∵BC =4CF ,S △ABC =12,∴S △ACF =13×12=4, ∵四边形CDEF 是平行四边形,∴DE ∥CF ,EF ∥AC ,∴S △DEB =S △DEC ,∴S 阴=S △ADE +S △DEC =S △AEC ,∵EF ∥AC ,∴S △AEC =S △ACF =4,∴S 阴=4.故选C .【点睛】本题考查平行四边形的性质、三角形的面积、等高模型等知识,解题的关键是熟练掌握等高模型解决问题,学会用转化的思想思考问题,属于中考常考题型.25.D【分析】连接DE ,因为点D 是中点,所以CE 等于4,根据勾股定理可以求出DE 的长,过点M 作MG ⊥CD 于点G ,则由题意可知MG =BC =CD ,证明△MNG ≌△DEC ,可以得到DE =MN ,即可解决本题.【详解】解:如图,连接DE .由题意,在Rt △DCE 中,CE =4cm ,CD =8cm ,由勾股定理得:DE 22CE CD +2248+45.过点M 作MG ⊥CD 于点G ,则由题意可知MG =BC =CD .连接DE ,交MG 于点I .由折叠可知,DE ⊥MN ,∴∠NMG +MIE =90°,∵∠DIG +∠EDC =90°,∠MIE =∠DIG (对顶角相等),∴∠NMG =∠EDC .在△MNG 与△DEC 中,90NMG EDC MG CDMGN DCE ∠=∠⎧⎪=⎨⎪∠=∠=︒⎩∴△MNG ≌△DEC (ASA ).∴MN =DE=.故选D .【点睛】本题主要考查了正方形的性质、折叠以及全等三角形,能够合理的作出辅助线并找出全等的条件是解决本题的关键.26.B【分析】由在ABC ∆中,ABC ∠和ACB ∠的平分线相交于点O ,根据角平分线的定义与三角形内角和定理,即可求得②1902BOC A ∠=+∠︒正确;由平行线的性质和角平分线的定义得出BEO ∆和CFO ∆是等腰三角形得出EF BE CF =+故①正确;由角平分线定理与三角形面积的求解方法,即可求得③设OD m =,AE AF n +=,则12AEF S mn ∆=,故③错误;E 、F 不可能是三角形ABC 的中点,则EF 不能为中位线故④正确.【详解】 解:在ABC ∆中,ABC ∠和ACB ∠的平分线相交于点O ,12OBC ABC ∴∠=∠,12OCB ACB ∠=∠,180A ABC ACB ∠+∠+∠=︒, 1902OBC OCB A ∴∠+∠=︒-∠, 1180()902BOC OBC OCB A ∴∠=︒-∠+∠=︒+∠;故(2)正确; 在ABC ∆中,ABC ∠和ACB ∠的平分线相交于点O ,OBC OBE ∴∠=∠,OCB OCF ∠=∠,//EF BC ,OBC EOB ∴∠=∠,OCB FOC ∠=∠,EOB OBE ∴∠=∠,FOC OCF ∠=∠,BE OE ∴=,CF OF =,EF OE OF BE CF ∴=+=+,。

新仁爱版七年级英语上册期中复习专题04 单项选择易错题100题(语法知识全覆盖)

新仁爱版七年级英语上册期中复习专题04 单项选择易错题100题(语法知识全覆盖)

专题04 单项选择易错题100题(语法知识全覆盖)1.—________— It is orange.A.What is this?B.What color is it?C.How is it?2.—________ is your new skirt, Lisa?—It’s green.A.Who B.What color C.How old3.—How are you?—________.A.You are OK B.I’m from China C.Fine, thanks4.My pants are new. His ________ old.A.is B.are C.am5.—______ your sister a teacher?—No, she ______ a worker(工人).A.Are; are B.Is; is C.Are; is6.—Excuse me, are you Tom?—______. Tom is my brother (兄弟).A.Yes, I am B.No, it isn’t C.No, I’m not7.—________ is your mother?—She is 39.A.How old B.How C.Where8.—________ bike is this?—I think it’s Liao Xinyi’s.A.What B.Who C.Whose9.Here ________ your pants.A.are B.is C.will10.—How old are you?—________.A.I’m eleven B.I’m fine, thanks C.That’s OK11.— Who’s that boy over there?— ________ is my cousin.A.You B.She C.He12.I ________ Amy. Lucy and I ________ good friends.A.am; am B.am; are C.am; is13.—________?—She is fine.A.Who is she B.What is she C.How is she 14.—________ are they?—They are Linda and Lily.A.Where B.What C.Who15.Jane is my friend. She ________ Canada.A.is B.are from C.is from 16.What ________ your parents going to do?A.are B.is C.am17.These ________ are ours. They aren’t yours.A.boxes B.box C.knife 18.—What color ________ the shoes?—________ white.A.is; It’s B.are; They’re C.are: It’s 19.—Hi, Jill. Is that ________ apple on the desk?—Yes, it is.A.a B.an C.the20.—________.—She is Miss Li.A.How’s she?B.Who’s she?C.Where’s she from? 21.—Eva, do you want ______________ to my party(聚会)?—Yes.A.coming B.to come C.come22.Her full name is Ann Smith, so ___________ is her family name.23.—Hi! I ________ Linda.—Hi! My name ________ Frank.A.am; am B.am; is C.is; am 24.—________ is my eraser?—Look! It’s on the desk.A.How B.Where C.Who 25.—Where ________ you from?—Lucy ________ from the USA, and I ________ from China.A.are; is; is B.are; is; am C.are; are; am 26.Jimmy and Tony are not in the same class, ________ they are good friends.A.and B.for C.but 27.—Look! Here’s a nice schoolbag. Is it ________?—No, it isn’t mine. It’s ________.A.your; Amy B.yours; Amy’s C.yours; Amy 28.—Mom, my jacket is too small.—I’ll buy ________ for you.A.one B.it C.that 29.—________ do you spell it?—C-A-P, cap.A.Who B.How old C.How 30.—Is this ________ English book?—Yes, it is.A.a B.an C.the 31.—Do you have a new dress?—Sorry, I don’t have ________.A.it B.that C.one 32.—Is that your teacher, Mr. Brown?—________A.Yes, we are.B.No, they aren’t.C.Yes, he is. 33.—What class are you in?A.Class four, Grade one B.Grade seven, class One C.Class Four, Grade Seven 34.—What does Kangkang look like?—He ________ two big eyes.A.is B.have C.has35.—________ you ________ a good friend?—Yes, I ________.A.Do; have; do B.Do; has; do C.Are; have; a 36.—This pair of gloves ________ for you, Mom.—Thank you, my dear.A.am B.are C.is37.—Does Wang Fang have a big nose?—No. She has a small ________.A.one B.that C.it38.—Annie, ________ is your pen?—Oh, it is blue.A.what time B.what color C.what class39.Quan Hongchan is from the ______. We are all Chinese.A.UK B.USA C.PRC 40.—Kangkang, ______ your sister ______ small hands?—Yes, she does.A.do; has B.does; have C.are; have41.The boy ________ short two years ago. Now he ________ tall.A.was; is B.is; is C.was; was42.This is ________ English teacher. She is Helen.A.Steve and Maria’s an B.Maria and Steve’s C.Maria’s and Steve’s 43.She has ________ long black hair.A.a B.an C./44.—Is the boy’s name Tony?—________A.Yes, he is.B.Yes, it is.C.Yes, she is.—He is tall and thin(瘦的).A.Who is he B.How old is he C.What does he look like 46.— Is the man in blue your dad?— _________. He is my uncle.A.No, he isn’t B.No, I’m not C.No, she isn’t 47.Look! That is ________ dad, Mr. Smith.A.Lucy’s and Lily B.Lucy’s and Lily’s C.Lucy and Lily’s 48.—Lisa, who is ________ girl?—She is my friend Sally and she’s from ________ UK.A.the; /B.the; the C.a; the49.I can see many ________ in the park.A.leaf B.leaves C.leafs50.________ a lot of good ________!A.What; wish B.What; wishes C.How; wishes 51.—I think doing ________ is good for us middle school students.—Yes, you’re right.A.eye exercise B.eyes exercise C.eye exercises 52.—How much ________ Tom’s sweater?—50 yuan.A.are B.am C.is53.Tina goes to the cinema _______ a week. She likes watching movies.A.two B.second C.twice54.Sally does well in her study, but ________ she is not very careful.A.sometimes B.always C.usually55.My brother enjoys doing sports and ________ favourite subject is PE.A.his B.her C.your56.—What class are you in?—I am in .A.Grade Seven, class Two.B.Class Two, Grade Seven.C.class two, grade seven.A.What B.Who C.How 58.—________ Penny and Henry from Japan?—No, ________.A.Are; they are B.Are; they aren’t C.Is; they are not 59.Good morning, boys and girls. 的同义句是_________。

初中数学试卷分类汇编易错压轴选择题精选:一次函数选择题(附答案)100(2)

初中数学试卷分类汇编易错压轴选择题精选:一次函数选择题(附答案)100(2)

初中数学试卷分类汇编易错压轴选择题精选:一次函数选择题(附答案)100(2)一、易错压轴选择题精选:一次函数选择题1.如图,过点1(1,0)A 作x 轴的垂线,交直线2y x =于点1B ;点2A 与点O 关于直线11A B对称;过点2(2,0)A 作x 轴的垂线,交直线2y x =于点2B ;点3A 与点O 关于直线22A B 对称;过点3A 作x 轴的垂线,交直线2y x =于点3B ;按3B 此规律作下去,则点n B 的坐标为( )A .(2n ,2n-1)B .(12n -,2n )C .(2n+1,2n )D .(2n ,12n +)2.若一次函数y x m =-+的图像经过点()12-,,则不等式2x m -+≥的解集为( ) A .0x ≥B .0x ≤C .1≥xD .1x ≤-3.函数2xy x =-中自变量x 的取值范围是( )A .0x ≥B .0x <且2x ≠C .0x <D .0x ≥且2x ≠4.小明家、食堂、图书馆依次在同一条直线上,小明从家去食堂吃早餐,接着云图书馆读报,然后回家.如图反映了这个过程,小明离家的距离与时间之间的对应关系,下列说法错误的是( )A .小明从家到食堂用了8minB .小明家离食堂0.6km ,食堂离图书馆0.2kmC .小明吃早餐用了30min ,读报用了17minD .小明从图书馆回家的平均速度为0.08km/min5.已知正比例函数y=kx ,且y 随x 的增大而减少,则直线y=2x+k 的图象是( )A .B .C .D .6.一次函数y kx b =+的图象如图所示,则下列说法:①0kb >;②若点(2,)A m -与(3,)B n 都在直线y kx b =+上,则m n >;③当0x >时,y b >.其中正确的说法是( )A .①②B .①③C .②③D .①②③7.在平面直角坐标系中,解析式为31y x =+的直线a ,解析式为33y x =的直线b ,如图所示,直线a 交y 轴于点A ,以OA 为边作一个等边三角形OAB ∆,过点B 作y 轴的平行线交直线a 于点1A ,以1A B 为第二个等边三角形11A BB ∆,…顺次这样做下去,第2020个等边三角形的边长是( )A .20192B .20202C .4038D .40408.一次函数y mx n =-+的图象经过第二、三、四象限,则化简22()m n n -+所得的结果是( ) A .mB .m -C .2m n -D .2m n -9.关于直线1y x =-+的说法正确的是() A .图像经过第二、三、四象限 B .与x 轴交于()1,0 C .与y 轴交于()1,0-D .y 随x 增大而增大10.甲、乙两人在直线跑道上同起点、同终点、同方向匀速跑步500m ,先到终点的人原地休息.已知甲先出发2s .在跑步过程中,甲、乙两人的距离y(m)与乙出发的时间t(s)之间的关系如图所示,给出以下结论:①a =8;②b =92;③c =123.其中正确的是( )A .①②③B .仅有①②C .仅有①③D .仅有②③11.如图,已知直线3:3l y x =,过点()0,1A 作y 轴的垂线交直线l 于点B ,过点B 作直线l 的垂线交y 轴于点1A ;过点1A 作y 轴的垂线交直线l 于点1B ,过点1B 作直线l 的垂线交y 轴于点2A ,…,按此作法继续下去,则点2020A 的坐标为( )A .()0,2020B .()0,4040C .()20200,2D .()20200,412.在平面直角坐标系中,将函数3y x =的图象向上平移6个单位长度,则平移后的图象与x 轴的交点坐标为( ) A .(2,0)B .(-2,0)C .(6,0)D .(-6,0)13.如图,直线y=-x+2分别交x 轴、y 轴于点A ,B ,点D 在BA 的延长线上,OD 的垂直平分线交线段AB 于点C .若△OBC 和△OAD 的周长相等,则OD 的长是( )A .2B .22C .522D .414.如图直线1l :y ax b =+与直线2l :y mx n =+相交于点P (1,2).则关于x 的不等式ax b mx n +>+的解集为( )A .x<1B .x>2C .x>1D .x<215.某公司市场营销部的个人收入y (元)与其每月的销售量x (万件)成一次函数关系,其图象如图所示,营销人员没有销售量时最低收入是( )A .1000B .2000C .3000D .400016.已知正比例函数()0y kx k =≠的函数值随的增大而增大,则一次函数1y x k =+的图象大致是( )A .B .C .D .17.在平面直角坐标系中,一次函数1y x =-的图象是( )A .B .C .D .18.如图,直线3y kx =+经过点(2,0),则关于x 的不等式30kx +≥的解集是( )A .2x >B .2x <C .2x ≥D .2x ≤19.已知直线2y x =与y x b =-+的交点的坐标为(1,a ),则方程组2y xy x b=⎧⎨=-+⎩的解是( )A .12x y =⎧⎨=⎩B .21x y =⎧⎨=⎩C .23x y =⎧⎨=⎩D .13x y =⎧⎨=⎩ 20.甲、乙两车从A 地出发,匀速驶向B 地.甲车以80km/h 的速度行驶1h 后,乙车才沿相同路线行驶.乙车先到达B 地并停留1h 后,再以原速按原路返回,直至与甲车相遇.在此过程中,两车之间的距离y (km )与乙车行驶时间x (h )之间的函数关系如图所示.下列说法:①乙车的速度是120km/h ;②m =160;③点H 的坐标是(7,80);④n =7.5.其中说法正确的是( )A .①②③B .①②④C .①③④D .①②③④21.将直线y=-2x 向上平移后得到直线AB ,直线AB 经过点(1,4),则直线AB 的函数表达式为( ) A .y=2x+2B .y=2x-6C .y=-2x+3D .y=-2x+622.如图,某工厂有甲、乙两个大小相同的蓄水池,且中间有管道连通,现要向甲池中注水,若单位时间内的注水量不变,那么从注水开始,乙水池水面上升的高度h 与注水时间t 之间的函数关系图象可能是( )A .B .C .D .23.如图,函数y =kx +b (k ≠0)的图象经过点B (2,0),与函数y =2x 的图象交于点A ,则不等式0<kx +b <2x 的解集为( )A .12x <<B .2x >C .0x >D .01x <<24.函数31x y x +=-中自变量x 的取值范围是( )A .x ≥-3B .x ≥-3且1x ≠C .1x ≠D .3x ≠-且1x ≠25.已知平面上点O (0,0),A (3,2),B (4,0),直线y =mx ﹣3m +2将△OAB 分成面积相等的的两部分,则m 的值为( ) A .1B .2C .3D .﹣126.下列函数的图象不经过第三象限,且y 随x 的增大而减小的是( )A .31y x =-+B .31y x =--C .31yxD .31y x =-27.对于函数31y x =-+,下列结论正确的是( ) A .它的图象必经过点(1,3) B .它的图象经过第一、三、四象限 C .当x >0时,y <0D .y 的值随x 值的增大而减小28.如图①,点P 为矩形ABCD 边上一个动点,运动路线是A →B →C →D →A ,设点P 运动的路径长为x ,S △ABP =y ,图②是y 随x 变化的函数图象,则矩形对角线AC 的长是( )A .25B .6C .12D .2429. 如图,直线l:33y x =,过点A(0,1)作y 轴的垂线交直线l 于点B,过点B 作直线l 的垂线交y 轴于点A 1;过点A 1作y 轴的垂线交直线l 于点B 1,过点B 1作直线l 的垂线交y 轴于点A 2;…按此作法继续下去,则点A 2015的坐标为( )A .(0,20154)B .(0, 20144)C .(0, 20153)D .(0, 20143)30.如图,直线l 分别与x 轴、y 轴交于点A ,B ,点C 为线段AB 上的一动点,过点C 分别作CE x ⊥轴于点E ,作CF y ⊥轴于点F ,若四边形OECF 的周长为6,则直线l 的解析式为( )A .6y x =-+B .6y x =+C .3yxD .3y x =-+【参考答案】***试卷处理标记,请不要删除一、易错压轴选择题精选:一次函数选择题 1.B 【分析】先根据题意求出点A 2的坐标,再根据点A 2的坐标求出B 2的坐标,以此类推总结规律便可求出点n B 的坐标. 【详解】 ∵1(1,0)A ∴11OA =∵过点1(1,0)A 作x 轴的垂线,交直线2y x =于点1B ∴()11,2B∵2(2,0)A ∴22OA =∵过点2(2,0)A 作x 轴的垂线,交直线2y x =于点2B ∴()12,4B∵点3A 与点O 关于直线22A B 对称 ∴()()334,0,4,8A B以此类推便可求得点A n 的坐标为()12,0n -,点B n 的坐标为()12,2n n - 故答案为:B . 【点睛】本题考查了坐标点的规律题,掌握坐标点的规律、轴对称的性质是解题的关键. 2.D 【分析】将(-1,2)代入y=-x+m 中求得m ,然后再解不等式2x m -+≥即可. 【详解】解:∵把(-1,2)代入y=-x+m 得1+m=2,解得m=1 ∴一次函数解析式为y=-x+1, 解不等式12x -+≥得1x ≤- 故答案为D . 【点睛】本题考查了一次函数与一元一次不等式,从函数的角度看就是找出使一次函数y=kx+b 的值大于(或小于)0时目变量x 的取值范围. 3.D 【分析】根据二次根式的性质和分式的意义,被开方数大于或等于0,分母不等于0,可以求出x 的范围. 【详解】由函数2xy x =-有意义,得:20x x ≥⎧⎨-≠⎩, 解得0x ≥且2x ≠.故选:D . 【点睛】本题考查了函数自变量的取值范围,函数自变量的范围一般从三个方面考虑:当函数表达式是整式时,自变量可取全体实数;当函数表达式是分式时,考虑分式的分母不能为0;当函数表达式是二次根式时,被开方数非负. 4.C 【分析】根据题意,分析图象,结合简单计算,可以得到答案. 【详解】解:根据图象可知:A. 小明从家到食堂用了8min ,故A 选项说法正确;B. 小明家离食堂0.6km ,食堂离图书馆0.8-0.6=0.2(km ),故B 选项说法正确;C. 小明吃早餐用了25-8=17(min ),读报用了58-28=30(min ),故C 选项错误;D. 小明从图书馆回家的平均速度为0.8÷(68-58=)0.08(km/min ),故D 选项正确. 故选C. 【点睛】本题考核知识点:函数的图形. 重点:分析函数图象,得到相关信息,并进行简单运算.5.D 【详解】∵正比例函数y kx =,且y 随x 的增大而减少,0k .∴<在直线2y x k =+中,200k ><,,∴函数图象经过一、三、四象限. 故选D . 6.B 【分析】由图象经过第一,二,三象限,可得k >0,b>0,可判断A ①,根据增减性,可判断②,由图象可直接判断③ 【详解】解:∵图象过第一,第二,第三象限, ∴k >0,b>0,∴0kb >,①正确, y 随x 增大而增大, ∵-2<3∴m <n ,②错误,又∵一次函数y kx b =+的图象与y 轴交于点(0,b ), 当0x >时,图像在第一象限,都在点(0,b )的上方,又是增函数, ∴这部分图像的纵坐标y>b ,③正确, 故①③正确 故选:B . 【点睛】本题考查一次函数图象上点的坐标特征,一次函数图象的性质,解题关键是灵活运用一次函数图象的性质. 7.A 【分析】延长A 1B 交x 轴于D ,A 2B 1交x 轴于E ,根据等边三角形的性质得OA=OD ,A 1B=BB 1,A 2B 1=B 2B 1,直线OB 的解析式为33y x =,得出∠BOD=30°,由直线a :31y x =+得出第一个等边三角形边长为1,由30°角的性质得BD=12,由勾股定理得OD=32,把x=32代入y=3x+1求得A 1的纵坐标,即可求得第二个等边三角形的边长,…,按照此规律得到第三个、第四个等边三角形的边长,从而求得第2020个等边三角形的边长. 【详解】解:延长A 1B 交x 轴于D ,A 2B 1交x 轴于E ,如图,∵△OAB 、△BA 1B 1、△B 1A 2B 2均为等边三角形, ∴OA=OD ,A 1B=BB 1,A 2B 1=B 2B 1,∵直线OB 的解析式为y=33x , ∴∠BOD=30°,由直线a :y=3x+1可知OA=1, ∴OB=1,∴BD=12,∴OD=22112⎛⎫- ⎪⎝⎭=32,把x=32代入y=3x+1得y=52,∴A 1D=52,∴A 1B=2,∴BB 1=A 1B=2, ∴OB 1=3,∴B 1E=32,∴OE=22332⎛⎫- ⎪⎝⎭=332,把x=332代入y=3x+1得y=112,∴A 2E=112,∴A 2B 1=4,同理得到A 3B 2=23,…,按照此规律得到第2020个等边三角形的边长为22019,故选A .【点睛】本题考查了图形类规律探究、一次函数图象上点的坐标特征、等边三角形的性质,含30°角的直角三角形的性质,以及勾股定理等知识,找出第n 个等边三角形的边长为2n-1是解题的关键.8.D【分析】根据题意可得﹣m <0,n <0,再进行化简即可.【详解】∵一次函数y =﹣mx +n 的图象经过第二、三、四象限,∴﹣m <0,n <0,即m >0,n <0,∴22()m n n -+=|m ﹣n |+|n |=m ﹣n ﹣n=m ﹣2n ,故选D .【点睛】本题考查了二次根式的性质与化简以及一次函数的图象与系数的关系,熟练掌握一次函数的图象与性质是解题的关键.9.B【分析】根据一次函数的性质对各选项进行逐一判断即可.【详解】解:A 、∵k=-1<0,b=1>0,∴图象经过第一、二、四象限,故本选项错误; B 、、∵当x=1时,y=0,∴图象经过点(1,0),故本选项正确;C 、∵当x=-1时,y=2,∴图象不经过点(-1,0),故本选项错误;D 、∵k=-1<0,∴y 随x 的增大而减小,故本选项错误.故选B【点睛】本题考查的是一次函数的性质,熟知一次函数y=kx+b (k≠0),当k >0,y 随x 的增大而增大,函数从左到右上升;k <0,y 随x 的增大而减小,函数从左到右下降是解答此题的关键.10.A【详解】解:∵乙出发时甲行了2秒,相距8m ,∴甲的速度为8/2=4m/ s .∵100秒时乙开始休息.∴乙的速度是500/100=5m/ s .∵a 秒后甲乙相遇,∴a =8/(5-4)=8秒.因此①正确.∵100秒时乙到达终点,甲走了4×(100+2)=408 m ,∴b =500-408=92 m . 因此②正确.∵甲走到终点一共需耗时500/4=125 s ,,∴c =125-2=123 s . 因此③正确. 终上所述,①②③结论皆正确.故选A .11.D【分析】根据所给直线解析式可得l 与x 轴的夹角,进而根据所给条件依次得到点A 1,A 2的坐标,通过相应规律得到A 2020坐标即可.【详解】解:∵直线l 的解析式为33y x =, ∴直线l 与x 轴的夹角为30.∵AB x 轴,∴30ABO ∠=︒.∵1OA =,∴2OB =.∴1A B ⊥直线l ,130BAO ∠=︒, ∴124A O OB ==, ∴()10,4A . 同理可得()20,16A ,…∴2020A 的纵坐标为20204,∴()202020200,4A . 故选D .【点睛】本题考查的是一次函数综合题,先根据所给一次函数判断出一次函数与x 轴夹角是解决本题的突破点;根据含30°的直角三角形的特点依次得到A 、A 1、A 2、A 3…的点的坐标是解决本题的关键.12.B【分析】先求出平移后的解析式,继而令y=0,可得关于x 的方程,解方程即可求得答案.【详解】根据函数图象平移规律,可知3y x =向上平移6个单位后得函数解析式应为36y x =+, 此时与x 轴相交,则0y =,∴360x +=,即2x =-,∴点坐标为(-2,0),故选B.【点睛】本题考查了一次函数图象的平移,一次函数图象与坐标轴的交点坐标,先出平移后的解析式是解题的关键.13.B【分析】根据直线解析式可得OA 和OB 长度,利用勾股定理可得AB 长度,再根据线段垂直平分线的性质以及两个三角形周长线段,可得OD=AB .【详解】当x=0时,y=2∴点B (0,2)当y=0时,-x+2=0解之:x=2∴点A (2,0)∴OA=OB=2∵点C 在线段OD 的垂直平分线上∴OC=CD∵△OBC 和△OAD 的周长相等,∴OB+OC+BC=OA+OD+AD∴OB+BC+CD=OA+OD+ADOB+BD=OA+OD+AD 即OB+AB+AD=OB+OD+AD∴AB=OD在Rt △AOB 中AB=OD=22222222OA OB +=+=故选B【点睛】本题主要考查了一次函数图象上点坐标特征、线段垂直平分线的性质、以及勾股定理. 14.C【分析】根据函数图象交点右侧直线y ax b =+图象在直线:y mx n =+图象的上面,即可得出不等式ax b mx n +>+的解集.【详解】解:直线1:l y ax b =+与直线2:l y mx a =+交于点(1,2)P , ∴不等式ax b mx n +>+解集为1x >.故选:C【点睛】此题主要考查了一次函数与不等式关系,利用数形结合得出不等式的解集是解题关键. 15.B【分析】根据图像可得出:一次函数经过点(1,7000)和(2,12000),利用待定系数法求出一次函数的表达式,再把0x =代入求解即可.【详解】解:由图可得:一次函数经过点(1,7000)和(2,12000)∴设一次函数的解析式为:y kx b =+,把点(1,7000)和(2,12000)代入得:7000212000k b k b +=⎧⎨+=⎩解得:50002000k b =⎧⎨=⎩ ∴50002000y x =+∴把0x =代入得:2000y =故答案选B【点睛】本题主要考查了一次函数的图像应用,利用待定系数法求一次函数的解析式是解题的关键.16.A【分析】先根据正比例函数y=kx (k ≠0)的增减性判断k 的符号,然后即可判断一次函数1y x k =+的大致图象.【详解】解:∵正比例函数y=kx (k ≠0)的函数值y 随x 的增大而增大,∴k >0,∴一次函数1y x k =+的图象经过一、三、二象限. 故选A .【点睛】此题主要考查一次函数的图像和性质,熟练掌握一次函数的图象和性质是解题关键. 17.A【分析】先确定一次函数解析式中k 与b 的符号,然后再利用一次函数图象及性质即可解答.【详解】解:一次函数y=1-x其中k=-1,b=1 其图象为:.故选:A.【点睛】本题考查了一次函数的图象,掌握一次函数的图象与性质是解答本题的关键.18.D【分析】写出函数图象在x轴上方及x轴上所对应的自变量的范围即可.【详解】解:当x≤2时,y≥0.所以关于x的不等式kx+3≥0的解集是x≤2.故选:D.【点睛】本题考查了一次函数与一元一次不等式的关系:从函数的角度看,就是寻求使一次函数y =kx+b的值大于(或小于)0的自变量x的取值范围;从函数图象的角度看,就是确定直线y=kx+b在x轴上(或下)方部分所有的点的横坐标所构成的集合.19.A【解析】将交点(1,a)代入两直线:得:a=2,a=-1+b,因此有a=2,b=a+1=3,即交点为(1,2),而交点就是两直线组成的方程组2y xy x b=⎧⎨=-+⎩的解,即解为x=1,y=2,故选A.20.A【分析】根据乙追上甲的时间求出乙的速度可判断①,根据乙由相遇点到达B点所用时间可确定m 的值,即可判断②,根据乙休息1h甲所行驶的路程可判断③,由乙返回时,甲乙相距80km,可求出两车相遇的时间即可判断④.【详解】由图象可知,乙出发时,甲乙相距80km,2小时后,乙车追上甲.则说明乙每小时比甲快40km,则乙的速度为120km/h.①正确;由图象第2﹣6小时,乙由相遇点到达B,用时4小时,每小时比甲快40km,则此时甲乙距离4×40=160km,则m=160,②正确;当乙在B休息1h时,甲前进80km,则H点坐标为(7,80),③正确;乙返回时,甲乙相距80km,到两车相遇用时80÷(120+80)=0.4小时,则n=6+1+0.4=7.4,④错误.所以正确的有①②③,故选A.【点睛】本题考查通过分段函数图像解决问题,根据题意明确图像中的信息是解题关键.21.D【分析】设直线AB的解析式为y=kx+b,根据平移时k的值不变可得k=-2,把(1,4)代入即可求出b的值,即可得答案.【详解】设直线AB的解析式为y=kx+b,∵将直线y=-2x向上平移后得到直线AB,∴k=-2,∵直线AB经过点(1,4),∴-2+b=4,解得:b=6,∴直线AB的解析式为:y=-2x+6,故选:D.【点睛】本题考查了一次函数图象与几何变换,求直线平移后的解析式时要注意平移k值不变.22.D【详解】开始一段时间内,乙不进行水,当甲的水到过连接处时,乙开始进水,此时水面开始上升,速度较快,水到达连接的地方,水面上升比较慢,最后水面持平后继续上升,故选D.23.A【分析】先利用正比例函数解析式确定A点坐标,然后观察函数图象得到,当x>1时,直线y=2x 都在直线y=kx+b的上方,当x<2时,直线y=kx+b在x轴上方,于是可得到不等式0<kx+b<2x的解集.【详解】设A点坐标为(x,2),把A(x,2)代入y=2x,得2x=2,解得x=1,则A点坐标为(1,2),所以当x>1时,2x>kx+b,∵函数y=kx+b(k≠0)的图象经过点B(2,0),∴x<2时,kx+b>0,∴不等式0<kx+b<2x的解集为1<x<2.故选A.【点睛】本题考查了一次函数与一元一次不等式的关系:从函数的角度看,就是寻求使一次函数y=ax+b的值大于(或小于)0的自变量x的取值范围;从函数图象的角度看,就是确定直线y=kx+b在x轴上(或下)方部分所有的点的横坐标所构成的集合.24.B【解析】分析:本题主要考查自变量的取值范围,函数关系中主要有二次根式和分式两部分.根据二次根式的性质和分式的意义,被开方数大于或等于0,分母不等于0,就可以求解.x ≥0,解答:解:∵3∴x+3≥0,∴x≥-3,∵x-1≠0,∴x≠1,∴自变量x的取值范围是:x≥-3且x≠1.故选B.25.B【分析】设点C为线段OB的中点,则点C的坐标为(2,0),利用一次函数图象上点的坐标特征可得出直线y=mx-3m+2过三角形的顶点A(3,2),结合直线y=mx-3m+2将△OAB分成面积相等的的两部分,可得出直线y=mx-3m+2过点C(2,0),再利用一次函数图象上点的坐标特征可求出m的值.【详解】解:设点C为线段OB的中点,则点C的坐标为(2,0),如图所示.∵y=mx﹣3m+2=(x﹣3)m+2,∴当x=3时,y=(3﹣3)m+2=2,∴直线y=mx﹣3m+2过三角形的顶点A(3,2).∵直线y=mx﹣3m+2将△OAB分成面积相等的的两部分,∴直线y=mx﹣3m+2过点C(2,0),∴0=2m﹣3m+2,∴m=2.故选:B.【点睛】本题考查了一次函数图象上点的坐标特征,利用一次函数图象上点的坐标特征,找出关于m的一元一次方程是解题的关键.【分析】由一次函数的图象与系数的关系可得出:当k <0,b>0时,一次函数y=kx+b 的图象经过第一、二、四象限.再对照四个选项即可得出结论.【详解】∵一次函数的图象不经过第三象限,且y 随x 的增大而减小,∴k <0,b>0,故选A.【点睛】此题主要考查了一次函数图象与系数的关系,找出图象不经过第三象限情况是解题的关键.27.D【分析】根据一次函数图象上点的坐标特征对A 进行判断;根据一次函数的性质对B 、D 进行判断;利用x >0时,函数图象在y 轴的左侧,y <1,则可对C 进行判断.【详解】A 、当1x =时,312y x =-+=-,则点(1,3)不在函数31y x =-+的图象上,所以A 选项错误;B 、30k =-<,10b =>,函数图象经过第一、二、四象限,所以B 选项错误;C 、当x >0时,y <1,所以C 选项错误;D 、y 随x 的增大而减小,所以D 选项正确.故选:D .【点睛】本题考查了一次函数的性质:k >0,y 随x 的增大而增大;k <0,y 随x 的增大而减小.由于y=kx+b 与y 轴交于(0,b ),当b >0时,直线与y 轴交于正半轴;当b <0时,直线与y 轴交于负半轴.28.A【分析】根据题意易得AB+BC=6,当点P 运动到C 点时三角形ABP 的面积为4,故而可求出AB 、BC 的长,进而求出AC .【详解】解:由图像及题意可得:AB+BC=6,当点P 运动到C 点时三角形ABP 的面积为4,即1=42ABP S AB BC ⋅=, ∴AB=2,BC=4,在Rt ABC 中,2225AC AB BC =+=;故选A .【点睛】本题主要考查函数与几何,关键是根据图像得到动点的运动路程,然后利用勾股定理求解线段的长即可.【分析】根据所给直线解析式可得l 与x 轴的夹角,进而根据所给条件依次得到点A 1,A 2的坐标,通过相应规律得到A 2015标即可.【详解】解:∵直线l 的解析式为:33y x , ∴直线l 与x 轴的夹角为30°,∵AB ∥x 轴,∴∠ABO=30°,∵OA=1, ∴AB=3,∵A 1B ⊥l ,∴∠ABA 1=60°,∴AA 1=3,∴A 1(0,4),同理可得A 2(0,16),…,∴A 2015纵坐标为:42015,∴A 2015(0,42015).故选:A .【点睛】本题考查的是一次函数综合题,先根据所给一次函数判断出一次函数与x 轴夹角是解决本题的突破点;根据含30°的直角三角形的特点依次得到A 、A 1、A 2、A 3…的点的坐标是解决本题的关键.30.C【分析】设点C 的坐标为(x ,y ),根据矩形的性质得到CF+CE=3,得到直线l 的表达式.【详解】解:设点C 的坐标为(x ,y ),∵四边形OECF 的周长为6,∴CF+CE=3,∴|x|+|y|=3,即y=x+3,∴直线l 的表达式为y=x+3,故选:C .【点睛】本题考查的是一次函数解析式的求法,灵活运用待定系数法求一次函数解析式是解题的关键.。

七年级上册科学易错题集

七年级上册科学易错题集

科学一、选择题1、下面是高兴同学在学习时收集的一些数据和对应的测量工具,完全正确的是()A、初中生的身高一般在1.6m左右————学生三角板B、初中生的质量一般在25Kg左右————台秤C、人的正常体温一定是35℃————体温计D、初中生的100米赛跑的成绩约秒————机械停表2、同一物体长度的四次测量结果记录分别为厘米、厘米、厘米、厘米,则测得该物体的长度值为()A、厘米B、厘米C、厘米D、厘米3、下列因素一定会使测量值偏小的是()A、刻度尺刻度不均匀B、视线斜视C、皮尺被拉长D、刻度尺太厚4、体温计的水银面在36.5℃上,某同学在未甩的情况下,分别量出生病同学的体温,测得的结果第一次为36.5℃,第二次为37.5℃,第三次为38.5℃,则()A、只有第一次正确B、只有第二次正确C、只有第三次正确D、第二次、第三次肯定正确,第一次也可能正确5、一温度计刻度均匀但示数不准,在一个标准大气压下,将它放入沸水中示数为98℃;放入冰水混合物中,示数为2℃;把该温度计悬挂在教室的墙壁上,其示数为26℃,教室的实际温度是( )A、24℃B、25℃C、26℃D27℃6、某同学在测量圆柱体周长时,把一张矩形纸条紧紧包在圆柱体外面,纸条的边没有与圆柱体的轴垂直(如图),然后在纸的重叠片用针扎个孔,把纸展开,再用刻度尺测两孔之间的距离,如此测出的圆柱体周长()A、因实验方法错误,一定偏大B、因实验方法错误,一定偏小C、因实验方法错误,偏大或偏小都有可能D、实验方法没有错误7、一支无刻度的温度计放在有刻度的尺旁,温度计在冰水混合物中水银在6毫米处,温度计在标准大气压下沸水银柱在206毫米处,温度计水银柱在100毫米处的温度为()A、100℃B、50℃C、48.5℃D47℃8、某同学用量筒量取酒精溶液。

他将装有酒精的量筒竖立放在水平桌面上,开始时俯视量筒内凹液面的最低处,读数为30毫升,倒出部分液体后,仍将量筒竖立放在水平桌面上,却仰视凹液面的最低处,读数为15毫升,则该同学实际倒出酒精溶液的体积()A、小于15毫升B、大于15 毫升C、等于15毫升D、无法确定9、下列说法中,正确的是()A、某测量结果是厘米,末位的“0”无意义B、0℃的冰要比0℃的水冷C、沙漏也可以用来作计量时间的标准D、50分米3的水比500毫升的水的体积要小10、以下操作导致的结果分析不正确的是()A、在用量筒测量液体的体积时,若视线是俯视的,则测得的体积比液体的真实体积要大B、一把刻度尺的刻度比标准刻度间隔小些,则用这把刻度尺测得的数值比真实值要大C、用累积法测细金属丝的直径时,若绕线时不紧密,则测量值比真实值要大D、用钢直尺在冬天和夏天分别测同一物体的长度时,夏天的测量值比冬天要大11、下列关于量筒的说法,不正确的是()A、读数时,用手拿起量筒进行读数B、用量筒可测得液体的体积C、使用量筒时,要看清它的最小刻度和测量范围D、读数时,视线要与凹形液面的最低处相平12、一个油漆匠给某人家油漆面积为12平方米的地板,用去油漆6升(1升=立方米),其油漆的平均厚度是()A、5毫米B、毫米C、毫米D、5微米13、现在通用的鞋的号码数是指人的脚跟到脚趾尖距离的厘米数。

(易错题精选)初中数学概率难题汇编附答案

(易错题精选)初中数学概率难题汇编附答案

(易错题精选)初中数学概率难题汇编附答案一、选择题1.下列事件是必然事件的是()A.打开电视机正在播放动画片B.投掷一枚质地均匀的硬币100次,正面向上的次数为50C.车辆在下个路口将会遇到红灯D.在平面上任意画一个三角形,其内角和是180【答案】D【解析】【分析】直接利用随机事件以及必然事件的定义分别判断得出答案.【详解】A、打开电视机正在插放动画片为随机事件,故此选项错误;B、投掷一枚质地均匀的硬币100次,正面向上的次数为50为随机事件,故此选项错误;C、“车辆在下个路口将会遇到红灯”为随机事件,故此选项错误;D、在平面上任意画一个三角形,其内角和是180°为必然事件,故此选项正确.故选:D.【点睛】此题考查随机事件以及必然事件,正确把握相关定义是解题关键.2.如图,飞镖游戏板中每一块小正方形除颜色外都相同.若某人向游戏板投掷飞镖一次(假设飞镖落在游戏板上),则飞镖落在阴影部分的概率是()A.12B.13C.49D.59【答案】C【解析】【分析】根据几何概率的求法:飞镖落在阴影部分的概率就是阴影区域的面积与总面积的比值.【详解】∵总面积为3×3=9,其中阴影部分面积为4×12×1×2=4,∴飞镖落在阴影部分的概率是4 9 .故答案选:C.【点睛】本题考查了几何概率的求法,解题的关键是根据题意将代数关系用面积表示出来,一般用阴影区域表示所求事件(A);然后计算阴影区域的面积在总面积中占的比例,这个比例即事件(A)发生的概率.3.一个盒子内装有大小、形状相同的四个球,其中红球1个、绿球1个、白球2个,小明摸出一个球不放回,再摸出一个球,则两次都摸到白球的概率是()A.12B.14C.16D.112【答案】C【解析】【分析】画树状图求出共有12种等可能结果,符合题意得有2种,从而求解.【详解】解:画树状图得:∵共有12种等可能的结果,两次都摸到白球的有2种情况,∴两次都摸到白球的概率是:21 126.故答案为C.【点睛】本题考查画树状图求概率,掌握树状图的画法准确求出所有的等可能结果及符合题意的结果是本题的解题关键.4.将一质地均匀的正方体骰子掷一次,观察向上一面的点数,与点数2的差不大于1的概率是()A.12B.13C.23D.56【答案】A【解析】【分析】根据正方体骰子共有6个面,通过观察向上一面的点数,即可得到与点数2的差不大于1的概率.【详解】∵正方体骰子共6个面,每个面上的点数分别为1、2、3、4、5、6,∴与点数2的差不大于1的有1、2、3.∴与点数2的差不大于1的概率是31 62 =.故选:A.【点睛】此题考查求概率的方法,解题的关键是理解题意.5.从﹣1、2、3、﹣6这四个数中任取两数,分别记为m、n,那么点(),m n在函数6yx=图象的概率是()A.12B.13C.14D.18【答案】B【解析】【分析】根据反比例函数图象上点的坐标特征可得出mn=6,列表找出所有mn的值,根据表格中mn=6所占比例即可得出结论.【详解】Q点(),m n在函数6yx=的图象上,6mn∴=.列表如下:mn的值为6的概率是41 123=.故选:B.【点睛】本题考查了反比例函数图象上点的坐标特征以及列表法与树状图法,通过列表找出mn=6的概率是解题的关键.6.随机掷一枚质地均匀的硬币两次,落地后至少有一次正面向上的概率是 ()A.34B.23C.12D.14【答案】A【解析】【分析】根据:随机掷一枚质地均匀的硬币两次,可能出现的情况为:正正,正反,反正,反反;可求落地后至多有一次正面朝下的概率.【详解】∵随机掷一枚质地均匀的硬币两次,可能出现的情况为:正正,正反,反正,反反.∴落地后至多有一次正面朝下的概率为34.故选:A【点睛】本题考核知识点:求概率.解题关键点:用列举法求出所有情况.7.一个不透明的袋子中装有白球4个,黑球若干个,这些球除颜色外其余完全一样.如果随机从袋中摸出一个球是白球的概率为13,那么袋中有多少个黑球()A.4个B.12个C.8个D.不确定【答案】C【解析】【分析】首先设黑球的个数为x个,根据题意得:4143=x+,解此分式方程即可求得答案.【详解】设黑球的个数为x个,根据题意得:41 43=x+,解得:x=8,经检验:x=8是原分式方程的解;∴黑球的个数为8.故选:C.【点睛】此题考查概率公式的应用.解题关键在于掌握概率=所求情况数与总情况数之比.8.下列说法:①一组对边平行,另一组对边相等的四边形是平行四边形;②经过有交通信号灯的路口,遇到红灯是必然事件;③若甲组数据的方差是0.3,乙组数据的方差是0.1,则甲数据比乙组数据稳定;④圆内接正六边形的边长等于这个圆的半径,其中正确说法的个数是()A.1个B.2个C.3个D.4个【答案】A【解析】【分析】根据平行四边形的判定去判断①;根据必然事件的定义去判断②;根据方差的意义去判断③;根据圆内接正多边形的相关角度去计算④.【详解】一组对边平行,另一组对边相等的四边形也有可能是等腰梯形,①错误;必然事件是一定会发生的事件,遇到红灯是随机事件,②错误;方差越大越不稳定,越小越稳定,乙比甲更稳定,③错误;正六边形的边所对的圆心角是60 ,所以构成等边三角形,④结论正确.所以正确1个,答案选A.【点睛】本题涉及的知识点较多,要熟悉平行四边形的常见判定;随机事件、必然事件、不可能事件等的区分;掌握方差的意义;会计算圆内接正多边形相关.9.将一个小球在如图所示的地砖上自由滚动,最终停在黑色方砖上的概率为( )A.59B.49C.12D.13【答案】A【解析】【分析】根据题意,用黑色方砖的面积除以正方形地砖的面积即可.【详解】停在黑色方砖上的概率为:59,故选:A.【点睛】本题主要考查了简单概率的求取,熟练掌握相关方法是解题关键.10.已知一个口袋中装有六个完全相同的小球,小球上分别标有1,2,5,7,8,13六个数,搅匀后一次从中摸出一个小球,将小球上的数记为m ,则使得一次函数y =(﹣m+1)x+11﹣m 经过一、二、四象限且关于x 的分式方程8x x π-=3x+88xx -的解为整数的概率是( ) A .12B .13C .14D .23【答案】B 【解析】 【分析】求出使得一次函数y=(-m+1)x+11-m 经过一、二、四象限且关于x 的分式方程8xx π-=3x+88xx -的解为整数的数,然后直接利用概率公式求解即可求得答案. 【详解】解:∵一次函数y =(﹣m+1)x+11﹣m 经过一、二、四象限,﹣m+1<0,11﹣m >0, ∴1<m <11,∴符合条件的有:2,5,7,8, 把分式方程m 8x x -=3x+88xx -去分母,整理得:3x 2﹣16x ﹣mx =0, 解得:x =0,或x =163π+, ∵x ≠8,∴163π+≠8, ∴m ≠8,∵分式方程8mx x -=3x+88xx -的解为整数, ∴m =2,5,∴使得一次函数y =(﹣m+1)x+11﹣m 经过一、二、四象限且关于x 的分式方程8mxx -=3x+88xx -的解为整数的整数有2,5, ∴使得一次函数y =(﹣m+1)x+11﹣m 经过一、二、四象限且关于x 的分式方程8mxx -=3x+88x x -的解为整数的概率为26=13;故选:B . 【点睛】本题考查了概率公式的应用、一次函数的图象与系数的关系以及分式方程的解,熟练掌握是解题的关键.11.袋子中装有4个黑球和2个白球,这些球的形状、大小、质地等完全相同,在看不到球的条件下,随机地从袋子中摸出三个球.下列事件是必然事件的是()A.摸出的三个球中至少有一个球是黑球B.摸出的三个球中至少有一个球是白球C.摸出的三个球中至少有两个球是黑球D.摸出的三个球中至少有两个球是白球【答案】A【解析】【分析】根据必然事件的概念:在一定条件下,必然发生的事件叫做必然事件分析判断即可.【详解】A、是必然事件;B、是随机事件,选项错误;C、是随机事件,选项错误;D、是随机事件,选项错误.故选A.12.由两个可以自由转动的转盘、每个转盘被分成如图所示的几个扇形、游戏者同时转动两个转盘,如果一个转盘转出了红色,另一转盘转出了蓝色,游戏者就配成了紫色下列说法正确的是()A.两个转盘转出蓝色的概率一样大B.如果A转盘转出了蓝色,那么B转盘转出蓝色的可能性变小了C.先转动A 转盘再转动B 转盘和同时转动两个转盘,游戏者配成紫色的概率不同D.游戏者配成紫色的概率为1 6【答案】D 【解析】A、A盘转出蓝色的概率为12、B盘转出蓝色的概率为13,此选项错误;B、如果A转盘转出了蓝色,那么B转盘转出蓝色的可能性不变,此选项错误;C、由于A、B两个转盘是相互独立的,先转动A 转盘再转动B 转盘和同时转动两个转盘,游戏者配成紫色的概率相同,此选项错误; D 、画树状图如下:由于共有6种等可能结果,而出现红色和蓝色的只有1种, 所以游戏者配成紫色的概率为16, 故选D .13.小英同时掷甲、乙两枚质地均匀的小立方体(立方体的每个面上分别标有数字1,2,3,4,5,6).记甲立方体朝上一面上的数字为x 、乙立方体朝上一面朝上的数字为y ,这样就确定点P 的一个坐标(x y ,),那么点P 落在双曲线6y=x上的概率为( ) A .118B .112C .19 D .16【答案】C 【解析】 画树状图如下:∵一共有36种等可能结果,点P 落在双曲线6y=x上的有(1,6),(2,3),(3,2),(6,1), ∴点P 落在双曲线6y=x 上的概率为:41=369.故选C .14.在一个不透明的口袋中装有4个红球和若干个白球,他们除颜色外其他完全相同.通过多次摸球实验后发现,摸到红球的频率稳定在25%附近,则口袋中白球可能有( )个. A .20B .16C .12D .15【答案】C【解析】【分析】由摸到红球的频率稳定在25%附近,可以得出口袋中得到红色球的概率,进而求出白球个数即可得到答案.【详解】解:设白球个数为x个,∵摸到红球的频率稳定在25%左右,∴口袋中得到红色球的概率为25%,∴41 44x=+,解得:12x=,经检验,12x=是原方程的解故白球的个数为12个.故选C【点睛】本题主要考查了随机概率,利用频率估计概率,根据大量反复试验下频率稳定值即概率得出是解题关键,应掌握概率与频率的关系,从而更好的解题.15.某市环青云湖竞走活动中,走完全部行程的队员即可获得一次摇奖机会,摇奖机是一个圆形转盘,被等分成16个扇形,摇中红、黄、蓝色区域,分获一、二、三等奖,奖品分别为自行车、雨伞、签字笔.小明走完了全程,可以获得一次摇奖机会,小明能获得签字笔的概率是()A.116B.716C.14D.18【答案】C【解析】【分析】从题目知道,小明需要得到签字笔,必须获得三等奖,即转到蓝色区域,把圆盘中蓝色的小扇形数出来,再除以总分数,即可得到答案.【详解】解:小明要获得签字笔,则必须获得三等奖,即转到蓝色区域,从转盘中找出蓝色区域的扇形有4份,又因为转盘总的等分成了16份,因此,获得签字笔的概率为:41 164,故答案为C.【点睛】本题主要考查了随机事件的概率,概率是对随机事件发生之可能性的度量;在做转盘题时,能正确找到事件发生占圆盘的比例是做对题目的关键,还需要注意,转盘是不是被等分的,才能避免错误.16.在一个不透明的袋子里装有四个小球,球上分别标有6,7,8,9四个数字,这些小球除数字外都相同.甲、乙两人玩“猜数字”游戏,甲先从袋中任意摸出一个小球,将小球上的数字记为m,再由乙猜这个小球上的数字,记为n.如果m,n满足|m﹣n|≤1,那么就称甲、乙两人“心领神会”,则两人“心领神会”的概率是()A.38B.58C.14D.12【答案】B【解析】【分析】【详解】试题分析:画树状图如下:由树状图可知,共有16种等可能结果,其中满足|m﹣n|≤1的有10种结果,∴两人“心领神会”的概率是105 168=,故选B.考点:列表法与树状图法;绝对值.17.某单位进行内部抽奖,共准备了100张抽奖券,设一等奖10个,二等奖20个,三等奖30个.若每张抽奖券获奖的可能性相同,则1张抽奖券中奖的概率是()A.0.1 B.0.2 C.0.3 D.0.6【答案】D【解析】【分析】直接利用概率公式进行求解,即可得到答案.【详解】解:∵共准备了100张抽奖券,设一等奖10个,二等奖20个,三等奖30个. ∴1张抽奖券中奖的概率是:102030100++=0.6, 故选:D .【点睛】本题考查了概率公式:随机事件A 的概率P (A )=事件A 可能出现的结果数除以所有可能出现的结果数.18.向一个半径为2的圆中投掷石子(假设石子全部投入圆形区域内),那么石子落在此圆的内接正方形中的概率是( ).A .2B .2πC .πD .2π【答案】D【解析】【分析】先得出圆内接正方形的边长,再用正方形的面积除以圆的面积即可得.【详解】∵半径为2的圆内接正方形边长为∴圆的面积为4π,正方形的面积为8, 则石子落在此圆的内接正方形中的概率是82=4ππ, 故选D .【点睛】本题考查了几何概率的求法:求某事件发生在某个局部图形的概率等于这个局部的面积与整个图形的面积的比.19.下列说法正确的是( ).A .“购买1张彩票就中奖”是不可能事件B .“概率为0.0001的事件”是不可能事件C .“任意画一个三角形,它的内角和等于180°”是必然事件D .任意掷一枚质地均匀的硬币10次,正面向上的一定是5次【答案】C【解析】试题解析:A. “购买1张彩票就中奖”是不可能事件,错误;B. “概率为0.0001的事件”是不可能事件,错误;C. “任意画一个三角形,它的内角和等于180°”是必然事件,正确;D. 任意掷一枚质地均匀的硬币10次,正面向上的一定是5次,错误.故选C.20.在平面直角坐标系中有三个点的坐标:()()0,2,2,01(),3A B C ---,,从、、A B C 三个点中依次取两个点,求两点都落在抛物线2y x x 2=--上的概率是( ) A .13 B .16 C .12 D .23【答案】A【解析】【分析】先画树状图展示所有6种等可能的结果数,再找出两点都落在抛物线2y x x 2=--上的结果数,然后根据概率公式求解.【详解】解:在()()0,2,2,01(),3A B C ---,三点中,其中AB 两点在2y x x 2=--上, 根据题意画图如下:共有6种等可能的结果数,其中两点都落在抛物线2y x x 2=--上的结果数为2, 所以两点都落在抛物线2y x x 2=--上的概率是2163=; 故选:A .【点睛】本题考查了列表法或树状图法和函数图像上点的特征.通过列表法或树状图法展示所有等可能的结果求出n ,再从中选出符合事件A 或B 的结果数目m ,然后根据概率公式求出事件A 或B 的概率.也考查了二次函数图象上点的坐标特征.。

中考英语单项选择易错题100道(含答案解析)

中考英语单项选择易错题100道(含答案解析)

中考易错题100道一、单项选择1.Which is the way to the __________?A. shoe factoryB. shoes factoryC. shoe’s factoryD. shoes’ factory2.________ it is today!A. What fine weatherB. What a fine weatherC. How a fine weatherD. How fine a weather3.This class ________ now. Miss Gao teaches them.A. are studyingB. is studyingC. be studyingD. studying4.We will have a _________ holiday after the exam.A. two monthB. two-monthC. two month’sD. two-months 5.There is no enough ________ on the corner to put the table.A. placeB. roomC. floorD. ground6.We can have _____ blue sky if we create _____ less polluted world.A. a; aB. a; theC. the; aD. the; the7.— Are you ________ American or English?— English. We are working in Wuhu.A. aB. \C. theD. an8.You like playing basketball, and he likes running, ____?A. don’t youB. doesn’t heC. do youD. does he9.— Why not take ________ umbrella with the sign “ Made in China”?It is _____ useful umbrella?— What _______ good advice it is!A. an; an; aB. an; a; \C. a; an; aD. \; an; a10.— When shall we meet again next week?—_______ day is possible. It’s no problem with me.A. EitherB. NeitherC. EveryD. Any11.Robert has gone to _________ city and he’ll be back in a week.A. otherB. the otherC. anotherD. any other12.— A latest magazine, please.— Only one left. Would you like to have ________?A. itB. oneC. thisD. that13.— Which book would you like to borrow?— ________ of the two books is OK with me.A. EitherB. BothC. AnyD. None 14.Mrs. Lee teaches ________ math. We all like her.A. weB. usC. ourD. ours 15.There are many trees on ________ side of the street.A. eitherB. anyC. allD. both 16.________ is the population of the city?A. How manyB. WhatC. How many peopleD. How much17.—Why don’t we take a little break?—Didn’t we just have _______?A. itB. thatC. oneD. this 18.The teacher asked the boy many questions, but he only answered ___ of them.A. someB. lotsC. eachD. few 19.About ______ the fans are waiting here. They want to see the great singer.A. two thousand ofB. two thousandC. thousand ofD. two thousands of20.— How many apples do I have?— You can have ______. I want none of them.A. oneB. allC. bothD. some 21.Japan is ________ the east of China. Fujian is ____ the southeast of China.A. in; inB. to; inC. on; toD. in; to 22.The postman shouted, “Mr. Green, here is a letter ________ you.”A. toB. fromC. forD. of 23.He hasn’t heard from his friend _________ last month.A. sinceB. by the end ofC. forD. until 24.— Jimmy lost his key yesterday.—________? It’s his third time in just one month.A. Has heB. Did heC. Was heD. Does he 25.You’ve passed the exam. I’m happy ______ you.A. onB. atC. inD. for26.I wonder ________ they finished so many different jobs in such a short time.A. whyB. howC. whenD. where 27.— Ought I to go right now?— ________.A. That’s very bad.B. Yes, you go ought toC. Yes, you oughtD. No, you ought not to28.I don’t know when he ________. When he _______ here, I’ll call you in a minute.A. will come; will arriveB. comes; arrivesC. will come; arrivesD. comes; will arrive29.He turned ________ the radio a little because his father was asleep.A. onB. downC. upD. off30.I don’t know the homework _______ today.A. onB. inC. ofD. for 31.— Would you like some coffee?— Yes, and please get me some milk. I prefer coffee ____ milk.A. withB. toC. ofD. on 32.They each ___ a book. Each of them ___ from China.A. has; areB. have; isC. are having; areD. is having; is 33.— ________ you ________ your book to the library?— Yes. I returned it yesterday.A. Did, returnB. Have, returnedC. Will, returnD. Do, return 34.Though it’s cloudy now, it ________ get sunny later.A. canB. mayC. mustD. need35.It is in the library, you _______ talk loudly.A. may notB. can’tC. needn’tD. mustn’t 36.If anyone wants to say something in class, you ______ put up your hands first.A. mustB. mayC. shouldD. can 37.The pen _________ him ten yuan.A. paidB. costC. tookD. spent 38.The train _________ for twenty minutes.A. leftB. has leftC. is leavingD. has been away39.— How many books _____ they ________?—Five. But they haven’t finished reading even one。

2020年初中中考重难点易错100题集锦322406

2020年初中中考重难点易错100题集锦322406

中考数学模拟试卷及答案解析学校:__________注意事项:1.答题前填写好自己的姓名、班级、考号等信息一、选择题1.下列事件中为必然事件的是( ) A .掷一枚均匀的骰子的点数是 6 B .掷一枚均匀的骰子的点数是奇数 C .掷一枚均匀的骰子的点数是偶数 D .掷一枚均匀的骰子的点数小于 72.下列计算:①0-(-5)=-5;②(-3)+(-9)=-12;③293()342⨯-=-;④(-36)÷(-9)=-4.其中正确的个数是( ) A .1个B .2个 C .3个D .4个3.从n 个苹果和3个雪梨中,任选1个,若选中苹果的概率是12,则n 的值是( ) A . 6 B . 3 C . 2 D . 1 4.下列方程中,是二元一次方程的是( ) A .5=+y xB .132=+y xC .3=xyD .21=+y x5.桌上放着6张扑克牌,全部正面朝下,其中恰有2张是老K.两人做游戏,游戏规则是:随机取2张牌并把它们翻开,若2张牌中没有老K ,则红方胜,否则蓝方胜.哪方赢的机会大?( ) A .红方B .蓝方C .一样D .不知道6.下列说法中正确的是( )A .从所有的质数中任取一个数是偶数是不可能事件B .如果一件事不是必然发生,那么它就不可能发生C .抛掷四枚普通硬币,掷得四个正面朝上和掷得四个反面朝上的概率一样大D .投掷一枚普通正方体骰子,“掷得的数是奇数”是必然发生的,因为骰子上有奇数7.从一副扑克牌中任意抽出一张,可能性相同的的是( ) A .大王与黑桃B .大王与10C .10与红桃D .红桃与梅花8.如图,ABD △与ACE △均为正三角形,且AB AC <, 则BE 与CD 之间的大小关系是( ) A .BE CD =B .BE CD >C .BE CD <D .大小关系不确定9.如图①,有 6 张写有汉字的卡片,它们的背面都相同,现将它们背面朝上洗匀后如图③摆放,从中任意翻开一张是汉字“自”的概率是( )A .12B .13C .23D .1610.如图 ,在 Rt △ABC 中,∠B = 90°,ED 垂直平分AC ,交AC 边于点D ,交BC 边于E. ∠C= 35°,则∠BAE 为( ) A . 10°B .15°C .20°D .25°11.对角的表示方法理解错误的是( )A .角可用三个大写字母表示,顶点字母写在中间,每边上的点的字母写在两旁B .任何角都可用一个顶点字母表示C .记角有时可在靠近顶点处加上弧线,注上数字来表示D .记角有时可在靠近顶点处加上弧线,注上希腊字母表示 12.下列说法中正确的个数有( ) ①两点确定一条直线; ②线段上有无数个点;③两条直线至多只有一个公共点; ④经过三个点能确定一条直线.A .1个B .2个C .3个D .4个13.已知某数的23比这个数大4,那么这个数是( )A .-12B .-8C .-6D .-4 14.下列等式中,正确的是( ) A .2325a a a +=B .321a a -=C .325a a a --=D .32a a a -+=-15.已知3x =,2y =,0x y ⋅<,则x y +的值为( ) A .5或-5B .1或-1C .5或1D .-5或-116.计算222222113(22)(46)32a cb a bc +-+---的结果是( ) A . 225106a b +B . 221106a b --C . 221106a b -+D . 225106a b -17.当 a=2,b=-1 时,代数式22a b-的值是( ) A .52B .2C .32D .1218.解是12x y =⎧⎨=-⎩的方程组是( ) A .135x y x y +=⎧⎨-=⎩B . 135x y x y +=-⎧⎨-=-⎩C . 331x y x y +=⎧⎨+=⎩D . 2335x y x y +=-⎧⎨-=⎩19.关于二次函数y=ax 2+bx+c 的图象有下列命题: ① 当c=0时,函数的图象经过原点② 当c >0且函数的图象开口向下时,方程ax 2+bx+c=0必有两个不等实根 ③ 函数图象最高点的纵坐标是4ac -b 24a ④ 当b=0时,函数的图象关于y 轴对称. 其中正确的命题的个数有 ( ) A .1个B .2个C .3个D .4个20.如图所示,BC 为一高楼,从地面A 用测角仪测得B 点仰角为α, 仪器高为 AD= b ,若DC=a ,则 BC 的高可以表示为( ) A .tan b a α+B .sin b a α+C .cos ab α+D .tan ab α+21.在盒子里放有三张分别写有整式1a +、2a +、2的卡片,从中随机抽取两张卡片,把两张卡片上的整式分别作为分子和分母,则能组成分式的概率是( ). A .13B .23C .16D .3422.已知正比例函数y=ax (a 为常数,且a≠0),y 随x 的增大而减小,则一次函数y ax a =-+的图象不经过( )A .第一象限B .第二象限C .第三象限D . 第四象限23.如图所示,已知渠道的截面是等腰梯形,尺寸如图所示,若它的内坡坡度是 0.8,则坡角的正弦值是( )A .41B .45C .54D .4124.以不共线的三点为平行四边形的其中三个顶点作平行四边形,•一共可作平行四边形的个数是( ) A .2个B .3个C .4个D .5个25.下列各图中,是轴对称图案的是( )26.为了了解一批数据在各个范围所占比例的大小,将这批数据分组,落在各小组里的数据个数叫做( ) A .频率B .频数C .众数D .中位数27.下列四个命题:①直径所对的圆周角是直角;②圆既是轴对称图形,又是中心对称图形;③在同一个圆中,相等的圆周角所对的弦相等;④三个点确定一个圆. 其中正确命题的个数为( ) A .1 个B .2 个C .3 个D .4 个28.以下列长度(同一单位)为长的四条线段中,不成比例的是( ) A .2,5,10,25B .4,7,4,7C .2,21,21,4 D .2,5,25,5229.下列图形:①线段;②角;③数字7;④圆;⑤等腰三角形;⑥直角三角形.其中轴对称图形是( ) A .①②③④B .①③④⑤⑥C .①②④⑤D .①②⑤30.如图,△ABC 中,CD ⊥AB 于 D ,DE ⊥AC 于 E ,则图中与△ADE 相似的三角形有( ) A .1 个B . 2 个C .3 个D .4 个31.若直线12y x =-沿y 轴向上平移3个单位,则所得的函数图象的解析式为( ) A .132y x =-+B .132y x =--C .1(3)2y x =-+D .1(3)2y x =--32.将某图形先向左平移3个单位,再向右平移4个单位,则相当于( ) A .原图形向左平移l 个单位 B .把原图形向左平移7个单位 C .把原图形向右平移l 个单位D .把原图形向右平移7个单位下列图形中,不是正方体平面展开图的是( )34.下列函数是反比例函数的是( ) D .A .y kx =-B .(0)x y kk=≠C .y =D .y =35.已知等腰三角形底边长为 10 cm ,周长为36 cm ,那么底角的余弦等于( ) A .513B .1213C .1013D .51236.21-的绝对值等于( ) A . 2 B .-2C .22 D .-22 37.若关于x 的方程332x k +=的解是正数,则k 为( ) A .23k <B .23k >C .为任何实数D .0k >38.如图,在Rt △ABC 中,CD 是斜边AB 上的中线,已知CD =2,AC =3,则sinB 的值是( ) A . 2 3B . 3 2C . 3 4D . 4 339.16的平方根是±4,用算式表示正确的是( )A 4=±B .4C .4=±D 4±二、填空题40.钢筋的横截面面积是0.25π,长度为h ,则钢筋的体积V=0.257πh ,这里常量是 ,变量是 .41.-(-2)-(-8)+(-3)-(+7)写成省略加号的和式是 . 42.找出满足下列条件的数(每空各填一个即可): (1)加上-8,和为正数: .; (2)乘以-8,积为正数: . 43.方程24153x x -+=-的解也是方程|8|x b -=的解,则b= . 44.要锻造一个直径为12 cm ,高10 cm 的圆柱形零件,需要直径为16 cm 的圆柱形钢条 .cm45.比较两条线段的大小的方法有两种:一种是 ;另一种是 . 46.已知A 、B 是数轴上两点,AB=2,点B 表示-1,那么点A 表示 .47.如图,AM ∥DN ,直线l 与AM ,DN 分别交于点B ,C 在线段BC 上有一点P ,直线l 绕点P 旋转.请你写出变化过程中直线l 与AD ,AM ,DN 围成的图形的名称.(至少写出三个).48. 如图,△ABD ≌△ACE ,点B 和点C 是对应顶点,AB=8 cm ,BD=7cm ,AD=3 cm ,则DC= cm.49.在甲、乙两地之间修二条笔直的公路,从甲地测得公路的走向是北偏东48°. 甲、乙两地间同时开工,若干天后,公路准确接通,则乙地所修公路的走向是南偏西 .50.如图,1l ⊥2l ,3l ⊥2l ,1l 3l ,则理由是 .51.甲、乙、丙三台机床生产直径为60 mm 的螺丝,为了检验产品质量,从三台机床生产的螺丝中各抽查了20个测量其直径,进行数据处理后,发现这三组数据的平均数都是60 mm ,方差依次为20.162S =甲,20.058S =乙,20.149S =丙,根据以上提供的信息,你认为生产螺丝质量最好的是 机床.52.如图,有一个圆锥形粮堆,其轴截面是边长为6cm 的正三角形ABC ,•粮堆母线AC 的中点P 处有一个老鼠正在吃粮食,此时小猫正在B 处,它要沿圆锥侧面到P •处捉老鼠,则小猫所经过的最短路程是_______m .(结果不取近似值)53.某种商品的进价为 800元,出售时标价为 1200元,后来由于该商品的积压,商店准备打折销售. 要保证利润率不低于5%,则至多可打 . 54.直角三角形在太阳光下得到的投影可能是 .55.如图,由四个全等的直角三角形拼成“赵爽弦图”.Rt ABF △中,90AFB ∠=,3AF =,AB=5.四边形EFGH 的面积是.56.袋中共有 5 个大小相同的红球和自球,任意摸出一球为红球的概率是25,则袋中红球有 个,白球有 个,任意模出两个球均为红球的概率是 .57.在△ABC 中,∠C= 90=,则sinA= ,cosA= , tanA= .58.已知I 为△ABC 的内心,∠B=50O ,则∠AIC= .59.已知抛物线y =x 2-mx+m -1与x 轴的两交点及顶点组成的三角形面积为8,则m 的值为 . 解答题60.如图,△EDC 是由△ABC 缩小后得到的,那么点E 的坐标是 .61.在“222a ab b □□”方框中,任意填上“+”或“-”.能够构成完全平方式的概率是 .62. 如图,反比例函数y =5x 的图象与直线y =kx(k>0)相交于B 两点,AC ∥y 轴,BC ∥x轴,则△ABC 的面积等于 个面积单位.63.已知一个正比例函数的图象经过点(-4,12),则这个正比例函数的解析式是 . 64.如图,在梯形ABCD 中,AD ∥BC ,E 为BC 上一点,DE ∥AB ,AD 的长为1,BC 的长为2,则CE 的长为___________.65.方程2x 2-x-2=0的二次项系数是________,一次项系数是________,•常数项是________.66. 用换元法解方程222(21)410x x -+-=,设221y x =-,则原方程化为关于y 的一元二次方程是 . 67.填空:(1) = ;(2) 9= ;= ;(4) = ;(5) (-= .68. 化简= . 69.如图,直角坐标系中,△ABC 的顶点都在网格点上.其中,A 点坐标为(2,一1),则△ABC 的面积为_____________平方单位.70.已知等腰△ABC 中,AB=AC ,∠B=60°,则∠A =_________.71. 的平方根是7,则x= .72.正方形有条对称轴,圆有条对称轴.三、解答题73.在长24 m,宽20 m的校园中央建一个面积为32 m2的长方形花坛,四周剩余部分做小路,且小路宽相等,请你帮助学校设计小路宽应为多少?74.如图所示的每个图形都是若干个棋子围成的正方形图案,图案的每条边(包括两个顶点)上都有 n(n≥2)个棋子,每个图案的棋子总数为S,按其排列规律推断,S 与n 之间的关系可以用式子来表示.44S n=-75.解下列方程(1)1.510.530.6x x--=(2)0.180.21 0.20.03x x--=76.若“*”是新规定的某种运算法则,设2*A B A B B=⋅-,试求:(1)(2)6-*的值;(2)若(5)10x*-=,求x的值.77.如图,直线AB、CD相交于点0,OB平分∠DOE,若∠DOE=64°,求∠ACC的度数.78.如图所示资料来源于2003年(南宁统计年鉴).□表示南宁市农民人均纯收入(元)(元)(1)分别指出南宁市农民人均纯收入和城市居民人均可支配收入,相对上一年哪年增长最快?(2)据统计.2000~2002年南宁市农民年人均纯收入的平均增长率为7.5%,城市居民年人均可支配收入的平均增长率为8.7%,假设年平均增长率不变,请你分别预计2004年南宁市农民人均纯收入和城市居民人均可支配收入各是多少?(精确到1元)(3)从城乡年人均收入增长率看,你有哪些积极的建议?(写出一条建议)79.如图所示,△ABC中,∠A=40°,∠ABC和∠ACB的外角平分线交于P.求∠P的度数.80.轮船在静水中每小时航行 a(m),水流速度是每小时 b(km),则该轮船在顺水中航行s(km)需要多少时间?s a b+81.已知235x x +-的值为 7,求2200739x x --的值.82.某商场正在热销2008年北京奥运会吉祥物“福娃”玩具和徽章两种奥运商品,根据如图提供的信息,求一盒“福娃”玩具和一枚徽章的价格各是多少元?83.从甲、乙、丙三个厂家生产的同一种产品中,各抽出8件产品,对其使用寿命进行跟踪调查,结果如下(单位:年):甲:3,4,5,6,8,8,8,10;乙:4,6,6,6,8,9,12,13;丙:3,3,4,7,9,10,11,12.三家在广告中都称该种产品的使用寿命是8年,请根据调查结果判断厂家在广告中分别运用了平均数、众数、中位数的的哪一种集中趋势的特征数.共计145元 共计280元84.若关于x 的方程52361x m x m -=-+的解大于-1且小于2,求m 的取值范围. 3344m -<<85. 分别写出下列各教的相反数,并把它们都表示在数轴上.2,142-,3.5,0,586.如图是某市一天的温度曲线图,其中x 表示时间(时),y 表示某市的温度(℃),根据图象回答下面问题:(1)这个函数反映了哪两个变量之间的关系?(2)这天几时温度最高、最低,它们相差多少度?(3)温度y 可以看成时间x 的函数吗?为什么?(4)求当x=21时的函数值,并说明它的实际意义.如图(1)所示为一上面无盖的正方体纸盒,现将其剪开展成平面图,如图(2)所示. 已知展开图中每个正方形的边长为1.(1)求在该展开图中可画出最长线段的长度?这样的线段可画几条?(2)试比较立体图中BAC ∠与平面展开图中B A C '''∠的大小关系?88.如图所示,在△ABC中,AD⊥BC于D,E,F分别是AB,AC的中点.若△ABC的周长是26 cm,EF=4 cm,求四边形AEDF的周长.89.红星中学团委为汶川地震灾区组织献爱心捐献活动,小明对本班同学的捐款情况进行40.小明还绘制了频数分布直方图.了统计,其中捐10元的人数占全班总人数的%(1)请求出小明所在班级同学的人数;(2)本次捐款的中位数是____元;(3)请补齐频数分布直方图.90.已知,□ABCD中,对角线AC,BD交于点O,AB=2cm,AB∶AC∶BD=1∶3∶4,求△ABO的周长.91.已知二次函数122--=x x y .(1)求此二次函数的图象与x 轴的交点坐标.(2)二次函数2x y =的图象如图所示,将2x y =的图象经过怎样的平移,就可以得到二次函数122--=x x y 的图象.92.小明为了测量某一高楼 MN 的高,在离 N 点 200 m 的 A 处水平放置了一个平面镜,小明沿 NA 方向后退到点C 正好从镑中看到楼的顶点M ,若 AC=l5m ,小明的眼睛离地面的高度为 1.6m ,请你帮助小明计算一下楼房的高度(精确到0.1 m).93.已知抛物线2y x px q =++的图象经过A(0,1)、B(2,一1)两点.(1)求p 、q 的值;(2)试判断点 P(—1,2)是否在此函数图象上?94. 在Rt △ABC 中,∠C=900, AB=13, BC=5 ,你能求AC 的长和∠A 的度数吗?试一试.95.如图,在离地面高度6米的C 处引拉线固定电线杆,拉线和地面成61角,求拉线AC 的长以及拉线下端点A 与杆底D 的距离AD (结果精确到0.01米).96.已知:如图,⊙O 与⊙C 内切于点A ,⊙O 的弦AB 交⊙C 于D 点,DE ⊥OB ,E 为垂足.求证:(1)AD=DB ;(2)DE 为⊙O 的切线.97.为了利用太阳光线或其他方法测量一棵大树的高度,准备了如下测量工具:•①镜子;②皮尺;③长为2m 的标杆;④高为1.5m 的测角仪,请你根据你所设计的测量方案,回答下列问题:(1)在你的设计方案中,选用的测量工具是(用工具序号填写)_______________.(2)在图中画出你的方案示意图.(3)你需要测量示意图中哪些数据,并用a 、b 、c 表示测得的数据__________.(4)写出求树高的算式,AB=___________m .A98.已知AD是△ABC的高,CD=6,AD=BD=2,求∠BAC的度数.99.在如图所示的矩形ABCD 中,AB=3,BC=4,P 是 BC 边上与点B、C不重合的任意一点,设 PA=x,D 到PA 的距离为 y,求:(1)y 关于x 的函数解析式,并写出自变量x 的取值范围;(2)画出函数的图象.100.下列各图是由若干盆花组成的形如正方形的图案,每条边(包括两个顶点)有n(n>1) 盆花,每个图案花盆的总数是S,按图中所示的图案回答下列各题:(1)填表:(2)当n=10时,S的值是多少?S、n表示的是变量还是常量?【参考答案】***试卷处理标记,请不要删除一、选择题1.D2.B3.B4.A5.B6.C7.D8.A9.A10.C11.B12.C13.A14.D15.B16.C17.A18.D19.C20.A21.B22.B23.A24.B25.B26.B27.C28.C29.C30.B31.A32.C33.D34.D35.A36.C37.A38.C39.C二、填空题40.0.25 ;V,h41.2+8-3-742.答案不唯一,如:(1)10;(2)-143.77844.5.62545.叠合法、度量法46.-3或l47.三角形,梯形,平行四边形等48.549.48°50.∥,在同一平面内,垂直于同一条直线的两条直线互相平行51.乙52.5353.7折54.三角形或线段55.156.2,3,1 1057 58.115°59.-2或660.(—2,2)61.1262.10 63.18y x =- 64.165.2,-1,-266.2210y y ++=67.(1)42;(2)45)233- 6869.570.60°71.7、4972.4,无数三、解答题73.8m74.44S n =-75.(1)57x =- (2)35x = 76.(1)-48 (2)7x =-77.32°78.(1)南宁市农民人均纯收入和城市居民人均可支配收入,相对于上一年都是2002年增长最快.(2)预计2004年农民人均收入:2524(1+7.5%)2≈2917(元)预计居民人均可支配收入:8796(1+8.7%)2≈10393(元)(3)建议:如加快农业建设步伐等等.51079.∠P=70°80.s a b+ 81.197182.125元和10元.83.甲使用了众数,乙使用了平均数,丙使用了中位数84.3344m -<<85.略-486.某市一天中时间与温度之间的关系;(2)这天15时温度最高为16℃,3时温度最低为2℃,相差l4℃;(3)可以;(4)10℃,21时温度为10℃87.解:(1这样的线段可画4条(另三条用虚线标出).(2)立体图中BAC ∠为平面等腰直角三角形的一锐角,45BAC ∴∠=. 在平面展开图中,连接线段B C '',由勾股定理可得:A B B C ''''== 又222A B B C A C ''''''+=,由勾股定理的逆定理可得A B C '''△为直角三角形.又A B B C ''''=,A B C '''∴△为等腰直角三角形.45B A C '''∴∠=,所以BAC ∠与B A C '''∠相等.88.18 cm89.解:(1)∵50%4020=÷∴小明所在班级同学有50人;(2)∵3525020=+,∴本次捐款的中位数是35元; (3) 如图:90.91.211+=x , 212-=x,0)和(21-,0).(2)11222=⨯--=-a b 214)2(144422-=⨯--⨯-=-a b ac ∴顶点坐标为(1,2-).将二次函数2x y =图象向右平移1个单位,再向下平移2个单位,就可以得到二次函数122--=x x y 的图象.92.∴BC ⊥CA ,MN ⊥AN ,∴∠C=∠N ,∵∠BAC=∠MAN..∴△BCA ∽△MNA. ∴BC AC MN AN =,即1.615200MN =, 1.620015213()MN m =⨯÷≈⋅. 93.(1)p=-3,q=1(2)∵231y x x =-+,当1x =-时,13152y =+++≠,∴P 不在函数图象上.94.AC=12,∠A=22°37′.95.AC=6.86米,AD=3.33米96.(1)连结OD ,证OD ⊥AB ;(2)连结CD ,利用三角形的中位线证明CD ∥OB .97.方案一:(1)①②;(2)测量方案示意图如图1;(3)CA=a ,CD=b ,DE (眼睛到地面的高)=c ;(4)AB=ac bm ;(1) (2)方案二:(1)②③; (2)测量方案示意图如图2:(其中BC 为太阳光线);(3)AC=a ,CD=b ,ED=c=2(m );(4)AB=ac b =2a b(m ). 98.当AD 在BC 边上时,∠BAC=105°,当AD 在CB 延长线上时,∠BAC=15°. 99.(1)过:D 作 DE ⊥AP ,垂足为 E ,连结 DP ,1122ADP S AB AD AP DE ∆=⋅=⋅,∴113422xy ⨯⨯=,12y x=.∵AB<AP<AC,∴35x <<(2)画图略.注意x的取值范围,它的图象是一段曲线. 100.(1)9,16,25,36;(2)100;S、n为变量。

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初中易错选择100题1.It’s very nice_____ you to get the tickets ______ the World Cup.A. for, ofB. of, forC. of, toD. to, for2.How many teachers are there in your school?______, I think. But I don’t know the exact number.A. hundredB. HundredsC. Hundreds ofD. Hundreds or thous ands3.Will you stay for lunch?Sorry, ______. My brother is coming to see me.A.I mustn’tB.I can’tC.I needn’tD.I won’t4.When he was there, he ______ go to that coffee shop at the corner after work every day.A. wouldB. shouldC. had betterD. might5.There ______ no hurry, need there?A. need beB. need to beC. doesn’tD. needs6.______ the sports meeting might be put off.Yes, it all depends on the weather.A.I’ ve been toldB. I’ve toldC. I’m toldD.I told7.Sh irley ______ a book about China last year but I don’t kno w whether she has finished it.A. has writtenB. wroteC. had writtenD. was writing8.We don’t allow ______ in this room.A. smokingB. to smokeC. people smokingD. people to smo king9.I haven’t got a chair ______. Will you make room for me?A. to sitB. to sit inC. for sittingD. sitting on10.It was so cold that the travelers had the fire ______ all the night.A. burningB. to burnC. burnD. burntCC B A A A D A B A11.She ______ his number in the phone book to make sure th at she had got it right.A. looked forB. looked upC. looked afterD. looked like12.Every morning, WE are asked ______ taken our temperature s.A .if we have B. if have we C. if we had D. if had we13.I will give ______ students ______ minutes for them to fini sh their exerciseA. the other; other fiveB. the other; another fiveC. other; five more D. other; more five14.I called yo u just now, but you weren’t in.Sorry, I ______ the reading room.A. was inB. have gone toC. studiedD. had been to15.The family ______ at the lunch table when someone came t o tell them what had happened at ______.A. were sitting; Mr BrownB. were sitting; Mr Brown’sC. was sitting; Mr BrownD. was sitting; Mr Brown’s16.Have you ______ your father recently?No. He doesn’t often write to me.A. heard aboutB. heard ofC. heard fromD. got from17.______did you sleep last night?I was reading too late to fall asleep.A. How longB. was doingC. How soon D, How18.Was Jack finished his homework yet?I’ve no idea, But he ______ it the whole afternoon.A. would doB. was doingC. didD. had done19.He’s never stolen anything before, ______ he?______. It’s his third time to be taken to police station.A. hasn’t; YesB. is; YesC. has; YesD. has; No20.I will spend as much time as I ______ the lesson.A. can go overB. can to go overC. can going overD. go o verB A A A BCD B C A21._____ you the truth, she knows nothing about it.A. To tellB. TellingC. To tellD. Told22.The old man walked in the street, ______.A. followed by his sonB. followed his sonB. and following his son D. and followed by his son23.Jim’s family went to visit ______ family last night.A. Miss Sun’sB. the Suns’C. the WhiteD. Miss Suns’24.They stopped ______ and ______ out to play when they __ ____ the bell ring or rest.A. working; went; heardB. work; to go; hearC. working; go; hearingD. working; going; heard25.I am going to Qingdao and stay there for a week.______ you are there, would you please buy some books for me?A. IfB. WhileC. SinceD. As soon as26.That woman has a bag in her right hand. What’s in her __ ____ hand?A. anotherB. otherC. oneD. The other27.Could you give me ______ second chance please?A. anB./C. theD. a28.Black, ______ father of ______ Tom, lost his new watch.A./,/B. the, theC. the,/ D/,the29.Do you know Susan’s address?Yes. She lives ( ) 201,Dongchang Road, Dalian City.A. inB. atC. alongD. on30.What do you think of the report on the UFO?Great! Many students were interested in it and they kept on st anding ______ the end of the meetingA. untilB. inC. onD. aboutA A A AB B D A B A31.The book ___it___ you want is on the desk.Which of the following isn’t right?A. thatB. whichC./D. it32.I’ll never forget the days __which____ we spent together in the country.A. whichB. on whichC. when D, on that33.Is that book ______ he borrowed on Friday?A. thatB. whichC. the oneD. who34.The number of people who_have__ cars of their own is inc reasing.A. hasB. haveC. there isD. there are35.The first school ___that___ we visited yesterday is not far f rom here.A. thatB. whichC. to whichD. where36.I have the same pen ___as you___.A. which you haveB. as yoursC. that you areD. as you37.The train ___on which___ she was traveling was five minut es late.A. thatB. on thatC. by whichD. on which38.The teacher said _those who__ wanted to go to the cinema must be there before 6:00,A. those whoB. thatC. whoD. which39.______ has questions is welcome to ask.A. WhoB. AnyoneC. ThoseD. Anyone who40.Tom is one of the people who ___as___ they are now.A. fromB. likeC. withD. asD A C B A D D A D D41.The teacher asked __us____ students to do homework oursel ves.A. theB. hisC. someD. us42._Are_ either you or I good at drawing?A. AmB. AreC. IsD. Do43.The room ______ as a meeting room.A. used to being usedB. was used to being usedC. used to be usedD. was used to be used44.The boy was seen ______ the piano at 9 yesterday evening.A. to playB. playC. playingD. playedst month Miss Han ______ a doctor.A. married withB. married toC. was married withD. got ma rried to46.It’s time for Meimei and ______ to the Palace Museu m.A.I goingB.I to goC. me goingD. me to go47.______ a year does your school have sports meeting? Twice a year.A .How often B. How soon C. How long D. How many times48.There are four pairs of socks to ______, but the woman do esn’t know ______ to buy.A. choose from; whichB. choose from; whatC. choose; which D. choose ;what49.It is in 1960 ___that___ Chinese first put out flag on Moun t Qomolangma.A. whenB. thatC. whichD. in which50.The old men who gave away lots of money _were spoken_ ____ highly of at yesterday’s meeting.A. spokeB. spokenC. was spokenD. were spokenD B C C D D D A B D51.I’m afraid I won’t come ______ 7 and 9. I will be at work then.A. untilB. betweenC. duringD. for52.Butter and cheese ______ in price.A. has gone upB. is gone upC. have gone upD. are gone u p53.______ neither you nor he enjoy fast food?A. DoB. DoesC. IsD. Are54.In our country every boy and every girl ______ the right to education.A. hasB. haveC. isD. are55.A man of words and not of deeds ______ a garden full of weed.A. likeB. likesC. is likeD. are like56.Would you like some coffee?Yes, please. By the way, do you have any milk? I prefer coff ee ______ milk.A. fromB. withC. toD. for57.These Germans want to have some ______ for supper, so t hey decide to catch ______ now.A. fish; manyB. fishes; muchC. fish; muchD. fishes; many58.What do you think of his surfing?Oh, no one does ______.A. goodB. wellC. betterD. best59.Aren’t you tired, Kate?______. I like going shopping.A. Not at allB. I’m so sorryC. You’re welcomeD. Yes, of course60.Don’t forget to come to my birthday party tomorrow.______A.I don’tB.I won’tC.I can’tD.I haven’tB C A A C B A C A B61.John plays football ______, if not better than David.A. as wellB. as well asC. so wellD. so well as62.Naturally, after I told her what to do, my daughter ______ go and do the oppsite!A. mayB. canC. mustD. should63.______ Yancheng today is more beautiful now. Mr.Jackson said he would visit it ______ fourth time.A. The;/B. The;theC./;aD. The;a64.To tell you the truth, I became a college student at 15.______.A. You must beB. Thank goodnessC. You don’t say soD.It doesn’t matter65.Excuse me, can you show me ______ to run the machine?A. whatB. ifC.whetherD. where66.Today some newly-produced mobile phones can take pictures ______ a camera.A. asB. forC. likeD. of67.I felt it is right ______ you should know.A. whetherB. andC. thatD. how68.A fool has gained nothing from the time ______, for he __ ____ nothing.A. passing; has paidB. passed; has been paidC. passing; has been paidD. passed; has paid69.This kind of T-shirt is ______.A. easily worn outB. easy worn outC. easy to worn outD. easily to be worn out70.Jim’s father said to him,“I hope you ______ what I ______ you to buy.A. didn’t forget, toldB. not to forget, have toldC. won’t forget, have toldD. haven’t forgotten, will tell61~70 B C D C D C B D A C71.English people ______ us e Mr before a man’s first name.A. neverB. usuallyC. oftenD. sometimes72.I enjoy learning English ______ it takes me a lot of time.A. unlessB. thoughC. becauseD. for73.I wonder ______ you would like to come to my birthday party.A. thatB. whetherC. that if D .that whether74.All the teachers thought _______ of the hard-working stude nt.A. highlyB. manyC. goodD. more75.A third of the population of the city _______ their own car s.A, has B. have C. had D. is76.His bag is nicer than _______ in his class.A, any other student B. the other students’ C. any other stude nts D. any student’s77.He _______ a good plan which we all agree.A. thought hardB. thought out C thought more of D. thought about78.I think swimming can make me very _______.A. goodB. healthC. comfortableD. well79.The buses _______ over 2 thousand people a day.A. takeB. bringC. carryD. sent80.The coductor kept _______ hot water to us.A. giveB. bringC. takingD. giving71~ 80 A A B A B B B D C D81.It’s your turn to be on duty. _______A. So am IB. So it isC. So I amD. So it is82.The TV needs .A. to repairB. repairedC. being repairedD. to be repaired83.They are _______ there.A. nearB. to nearC. near toD. nearly84.The boy said he wouldn’t eat _______.A. any longerB. no longerC. any more D, no more85.Nobaby noticed the thief slip into the shop, because the lig hts happened to _______.A. put outB. turn out C .give out D. go out86.The days are short, _______ it is noe December.A. becauseB. forC. goesD. want87.The education in China has developed _______ these days.A. quickB. highC. highlyD. wildly88.Will you tell me a story?OK. Shall I _______ it in English or in Chinese?A. tell, tellB. speak, tellC. tell, speakD. tell, say89.The lady is always _______ in white at the party.A. wearingB. dressingC. wornD. dressed]90.They _______ 3000 English words by the end of next month.A. learnedB. had learnedC. will learnD. have learned81~90 B D D C D B C A D C91.Mr.Black, some boys are going to flight.You’d better _______ the police.A. send forB. send toC. look forD. look over92.Many ( ) trees must be planted every year.A. thousandB. thousand ofC. thousands ofD. thousand93.The post offic e is not far from here. It’s only ten ( ) by bi ke.A. minuteB. minutesC. minute’sD. minutes’94.She doesn’t know the school, but it’s ( ) to be quite a good one.A. toldB. spokenC. talkedD. said95.You must leave here now ( ) your mother can get some m ore rest.A. becameB. thoughC. so thatD. so96.Lucy, ( ) all your things on the desk.A. puts awayB. put awayC. takes awayD. take away97.(At the doctor’s) It’s nothing serious, doctor?No, ( ).A. you’ll be all right soonB. You won’t be all right soonB. There’s some trouble with you D. It’s very serious98.We can’t buy ( ) much mutton with ( ) little money.A. so, muchB. such, soC. so, soD. such, such99.There is ( ) W in the word woman ,and ( ) M is the third letter of the word.A. a; anB. an; /C. an; the D .a; the100.Need he come a little earlier?Yes, he ( ).can B. must C. need D. needn’t81~90 B D D C D B C A D C。

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