广东省广州市白云区2019届九年级上学期期末考试
广东省广州市白云区第三初级2018-2019学年中学九年级上学期物理期末考试试卷及参考答案
（1） 小灯泡正常发光时的电阻。 （2） 小灯泡正常工作2min，消耗的电能。 （3） 闭合开关S，将变阻器的滑片移到最右端B点时，电流表的示数为0.4A，求此时小灯泡的实际功率。
四、实验探究题
23. 小明和小红一起做探究杠杆平衡条件的实验：
（1） 实验前，将杠杆的中点置于支架上，发现杠在如图甲所示的位置保持静止，此时杠杆________（选填“是”或“不 是”）处于平衡状态，小明将左端的平衡螺母向右调，小红认为也可以将右端的平衡螺母向________调（选填“右”或“左”）
16. 如图所示电路，若闭合开关S，电路将________路（断/短/通）．若要使电路中的两灯L1和L2并联，可改变导线__ ______（a/b/c）的接法；若电源电压为3V，L1、L2的电阻分别为10Ω和15Ω，则改变接法闭合开关后，电流表示数为___ _____A。
17. 小红在研究电阻对电流的阻碍作用时，用到了①铅笔芯、②金属刀片、③塑料三角尺、④塑料笔袋、⑤橡皮等物品 ，其中属于绝缘体的有________（只填序号）；小红在探究“电阻的大小与什么因素有关”的活动中，发现实验器材中电阻 丝只有一根，其他器材足够，这种情况下可以完成的是探究导体电阻与________的关系。
14. 如图所示，闭合开关后，电压表V1测量________两端的电压，电压表V2测量________两端的电压，电压表V3测 量________两端的电压，其中电压表V1、V2和V3的示数分别为U1、U2和U3 ， 则三个电表示数之间存在的关系是______ __。
15. 如图所示，闭合开关S，发现电灯L1、L2均不亮，电流表示数为零，说明电路存在________ 故障，用一根导线进 行检测，发现将导线接在b、c 间两灯都不亮，电流表无示数，将导线接在a、b 间，L2亮，电流表有示数，则电路的故障 是________。
2019-2020学年广东省白云区九年级上学期期末考
2019-2020学年（上）白云区期末考初三英语一、语法选择（共15小题每题1分共15分）I still remember I fell in love with English from a very young age, because I thought it was such __1__useful language. Full of strong wishes of__2__English, I began to learn it. But soon I found it__3__than expected. There were __4__words, expressions and many other things to remember. And even if you know__5__,you can’t use them correctly and exactly. And I did rather__6__in my first English test. I was worried about it.This made me__7__my interest in English little by little.While I was in trouble, my English teacher gave me__8__help. I knew that interest didn’t mean__9__andI should have some learning methods. I did__10__he said and tried many different waysof learning English. As the days went by, I could__11__better and better and became more and more__12__in it.During summer vacation, an old lady from America visited my school. She had a talk with us. It was myfirst time to meet a foreigner. I got__13__nervous at first, but soon I found it exciting__14__with her, and I learneda lot from her.__15__I wish to practise speaking English with foreigners every day!1. A. an B. a C. the D. /2. A. learn B. learned C. learning D. to learn3. A. difficult B. difficultly C. most difficult D. more difficult4. A. too many B. too much C. much too D. many too5. A. what to write C. how should you write themC. what to write themD. how to write them6. A. badly B. worse C. bad D. worst7. A. dropped B. drop C. dropping D. drops8. A. much B. many C. more D. most9. A. nothing B. anything C. something D. everything10. A. so B. like C. as D. so that11. A. doing B. does C. do D. did12. A. interesting B. interested C. interest D. interests13. A. a little B. little C. a few D. few14. A. talk B. talking C. talks D. to talk15. A. What B. Why C. When D. How二、完形填空（共10小题每小题1.5分共15分）Piotr is an athlete(运动员) from Poland. Recently he has done something that __16__ many people’s hearts.Piotr __17__ the 2016 Summer Olympics. He auctioned off the silver medal(拍卖银牌) he won in the Olympics, helping a young patient travel to New York for a better treatment(治疗).T he boy’s name is Olek. There’s __18__wrong with his eyes. And the only hope for treatment is in New York, far from Poland.“__19__ an Olympic medal is an athlete’s dream,” Piotr said. “Of course the most valuable is gold. I’ve made a great __20__ to get it. However this time I didn’t succeed. Luckily, life gave me a chance to increase the __21__o f my silver medal.”Piotr said the boy’s mother wrote to him for help. A charity(慈善机构) in Poland has already collected a third of the money needed. They __22__ needed another＄84,000for the treatment.So Piotr made a decision to sell his silver medal to get enough money. And the boy is able to go to New York now.“We are __23__ to say that together we can make miracles(奇迹). My silver medal today is worth much more than it was just a week ago. It is __24__ the life and health of little Olek. This is our great success.”At the age of 33, Piotr isn’t __25__ to take part in the next Olympics. But his whole country will be proud of having such a hero.16.A. breaks B. hurts C. touches D. interests17.A. took part in B. took care of C. took pride of D. looked up to18.A. everything B. something C. anything D. nothing19.A. Losing B. Making C. Driving D. Winning20.A. list B. effort C. mistake D. noise21.A. courage B. pity C. value D. doubt22.A. still B. already C. yet D. rather23.A. sad B. embarrassed C. sorry D. proud24.A. worth B. valuable C. believable D. burning25.A. exchanged B. influenced C. allowed D. expected三、阅读（共两节满分45分）第一节阅读理解（共20小题每题2分共40分）AThere was a zoo named Kananvan near the coast. It was famous all over the world for its rare species(稀有物种)and democracy(民主).The leader of the animals in the zoo was Gajapati. He was the only animal who was not inside a cage, and thus enjoyed freedom.G ajapati’s job was to show the visitors around the zoo. He was a caring and clever leader. During his rounds he kept his ears and eyes open for any trouble.And as soon as his work was over, he would help other animals deal with their problems.All the animals in the zoo loved, admired and respected him.Even though Gajapati had freedom, it sometimes upset him to see the suffering of the other animals in cages.If only he could give the animals their freedom! But Gajapati knew there was no escape (逃走) from Kananvan.One day, it rained heavily and the rain damaged (破坏) some of the cages badly.It was a Monday—aholiday for the zoo and there were no visitors.“Listen, Friends. God has given us a chance to achieve what we have always wanted, ” said Gajapati.“What is that, Gajapati?” asked Neelu, a blue and red parrot.“Freedom! We can be free now.”“How?” asked the rest.“M ost of the cages are badly damaged. It wouldn’t be difficult for the animals and birds to get out.” Everyone nodded, and the great march to freedom began. They walked the whole afternoon, evening and night without stopping until they disappeared in the forest.26.What was Kananvan famous for?A.Its beautiful scenery.B. Its democracy.C. The African elephants.D. The leader of the zoo.27. From the passage, we can learn that Gajapati was _______________.A. lazyB. lonelyC. responsibleD. careless28.What did Gajapati think of his life in Kananvan?A. He enjoyed his life because he was the only animal who had freedom.B. He always felt lonely because no one wanted to make friends with him.C. Although he had freedom, sometimes he felt sad for the other animals in cages.D. He hated the life in Kananvan and wanted to escape on his own.29.Which of the following is TRUE?A. The other animals didn’t like Gajapati.B. The animals in Kananvan never had enough food.C. Some of the animals didn’t want to escape from Kananvan.D. The animals escaped from Kananvan on a Monday.30.Why could the animals escape from their cages?A. Because it wasn’t easy for the animals to get out of their cages.B. Because the cages had already been broken by visitors.C. Because the cages were damaged by the rain.D. Because a human helped the animals open the cages.BFor many Africans who live in China, winter is much colder than that in their home countries. But winter is also their favorite season of the year—they get to experience something many Africans will only ever see on television.Some equatorial(赤道的) countries in Africa have no winter to speak of. They experience temperatures between 20℃and 35℃all year round.In a survey I carried out, 97 percent of Africans said winter was their season of choice in China. Many Africans said if it weren’t for the snow, spring and fall would be their favorites because of the comfortabletemperatures.China has many wonderful man-made historical and natural tourist spots(地点)in each of its 23provinces. However, for many Africans the chance to make snowballs, ski and enjoy the beautifulsnow-covered scenery while taking selfies is really valuable.Martin Grant, a student at the Shandong University Qingdao campus, left for his skiing trip in Jinan.He said he couldn’t miss the chance to travel to a ski resort(旅游胜地)in Jinan in order to give the sport a try. “I really couldn’t wait to go skiing,” he said. “I had a lot of fun, although it was not as easy as Iexpected. I fell down a lot.”Some Africans study or work in the southern provinces of China. They said they traveled north in the winter just to see the snow-covered scenery in northern China and take photos for social media.31. Many Africans like winter in China because _______________.A. they can talk about winterB. they could have a trip in winterC. they love snowD. they feel comfortable in winter32. From the fifth paragraph we know that _______________.A. Martin Grant liked drinking snow waterB. Martin Grant didn’t do well in skiingC. there is no snow in QingdaoD. Martin Grant couldn’t have fun in Qingdao33. W hat does the underlined phrase “taking selfies” mean?A. Writing a diary.B. Reporting one’s own story.C. Talking to oneself.D. Taking photos of oneself.34. Which of the following statements is TRUE, according to the passage?A.Africans don’t like hot temperatures in China.B. African students are good at skiing.C. Most Africans like winter more than spring and autumn in China.D. Most Africans like skiing instead of seeing snow-covered scenery.35. What is the best title for this passage?A. Travel to Northern ChinaB. Why Africans Love Winter in ChinaC. Why Africans Like Living in ChinaD. The Beautiful Snow-covered Scenery in Northern ChinaCAn eight-year-old boy named Wang Fuman walked 4.5 kilometers through freezing snow to school in ruralZhaotong, Yunnan Province, and arrived with his hair and eyebrows covered in ice. His classmates laughed and his teacher took a picture and posted it online. The picture spread very quickly online. People called him “Snowflake Boy”,and they were deeply moved by the little boy.Wang Fuman finished a three-day tour of Beijing on Sunday. He visited the capital with his father andhis sister at the invitation of two media organizations.“The biggest difference between Beijing and my hometown is Beijing isn’t cold, but my hometown is,” Wang said. “Beijing is much warmer than my home because every family here has heating, but we can only warm ourselves by burning wood.”On Saturday morning, the family witnessed the flag-raising ceremony at Tian’ anmenSquare.“That was my favorite part of the tour in Beijing,” Wang said at a news conference on Sunday.After leaving the square, Wang and his sister tried rock climbing and touched a real gun, overseen by the Beijing high security police (SWAT) team. The police officers also taught the children a few combat（搏斗）skills.“The real gun was a lot heavier than my toy guns,” Wang said. “They(SWAT officers) train really hard every day, but I still want to be a policeman.”The family also went to the People’s Public Security University of China on Saturday afternoon. They visited the student’s dormitory and were taught how to fold a quit(被子)“a s tight as tofu”.Wang’s family lives in a cold mountainous area. Both and his sister, Wang Fumei, go to the village primaryschool. Their mother abandoned(抛弃) the family two years ago.Wang Gangkui, the children’s father, thanked people for their support and said, “I just want my children to have a better and warmer school to go to, and have good jobs in the future.”36.How did Wang Fuman become popular?A. He took part in an activity on the Internet.B. His picture was put online by his teacher.C. He was interviewed by a newspaper office.D. Hewon first prize in a national competition.37.What does Wang Fuman think is the biggest difference between Beijing and his hometown?A. Beijing is much bigger than his hometown.B.Beijing has more people than his hometown.C.Beijing is much more crowded than his hometown.D.Beijing is much warmer than his hometown.38.Who invited Wang Fuman to Beijing?A. The Beijing SWAT team.B. Two media organizations.C. The Beijing government.D. The People’s Public Security University of China.39.W hat didn’t Wang Fuman do in Beijing?A. Visit Tian’ anmen Square.B. Learn combat skills.C. Learn to make tofu.D. Visit the People’s Public Security University of China.40.What can we learn from the passage?A. Wang Fum an’s family warm themselves by burning coal.B. Wang Fuman’s mother died two years ago.C. Wang Fuman wants to be a policeman in the future.D. People in society are not interested in Wang Fuman’s life.DGreat Opportunity!Beeville Publishing Inc. is looking for a great partner to join their Goliad and Refugio County Sales Team.If you are outgoing, well organized, have outside sales experience, enjoy working with different businesses in the community, and enjoy being creative, this could be the opportunity you’ve been looking for!This position offers a strong base salary, good working environment, health care, and year-end bonus(奖金).Familiarity with the region is a plus, because every account executive(业务代表) can sell into all publications(出版物) owned in the group, expanding sales opportunities even more.41. What kind of person is the company looking for?A. A teacher.B. A doctor.C. An engineer.D. A salesman.42. If you want to work in the company, you need to _______________.A. enjoy travelingB. enjoy working in an officeC.be creativeD. enjoy working alone43. W hich of the following isn’t offered by the company?A. A good salary.B. Yearly bonus.D. Health care. D. Yearly travel.44. Which kind of experience is required by the company?A. Advertising experience.B. Marketing experience.C. Sales experience.D. Managerial experience.45. If you are interested in the job, you can contact the company by _______________.A. jeef@B. 70461568C. jeff@D. 70416568第二节阅读填空（共5小题每题1分共5分）Having a clear picture of what their future will look like can encourage students to keep going when they meet difficulties, according to a study by Northwestern University in the US.College is a time of great opportunity for some. _____46_____Some students from lowersocioeconomic (社会经济的) status(SES) backgrounds often face greater challenges than others.And this can lead to withdrawal (退缩) from difficult situations, such as when communicating with theirteachers or taking tests andexams.The researchers wanted to know if students’ responses to challenges would improve when they looked forward to the future._____47_____When faced with difficulties, can people take positive action if they imagine a successful future for themselves?There were two experiments. One included 93 females(女性) students._____48_____ Students were first asked either to write about their past or their future success. After that, they were filmed during an interview with a teacher. And then they had to complete a difficult test. The research team noted whether students’ body language was full of courage and confidence. _____49_____The results showed that imagining a successful future can help especially female students from lower SES women who wrote about their future life seemed to be more active compared to those who wrote about their past. _____50_____And the confidence helped them to put more effort into the test andhad an indirect effect on their performance.So it is very helpful to imagine a bright future.A.The other had 185 students, including 101 women.B. But it can be stressful for others.C. They showed more confident body language.D. This is based on a great idea.E. And they measured the amount of effort they put into the test.四、写作（共3节满分35分）第一节单词拼写（共6小题，每小题1分，共6分）51. The hammer is not r__________. It is just a toy.52. The basketball team of Class One b__________the team of Class Two by a large score yesterday.53. The sofa is broken. It isn__________ to buy a new one.54. You are still in bed at 2 o’clock in the afternoon! You are really the l__________person I have ever seen.55. Mary fell off her bike yesterday and injured her k__________.56. You should do more exercise every day, because it cana__________the risk of catching diseases.第二节完成句子（共7题，每小题2分，共14分）57. 不要背后嘲笑别人。
2018-2019学年广东省广州市白云区九年级(上)期末物理试卷
2018-2019学年广东省广州市白云区九年级（上）期末物理试卷副标题题号一二三四五六总分得分一、单选题（本大题共11小题，共33.0分）1.一位小朋友正帮助妈妈推石磨来磨米浆。
他和妈妈分别在图中位置单人都能推动石磨。
小朋友在离石磨较远端推磨相比妈妈能够（）A. 省距离B. 省力C. 省功D. 省力和省功2.如图所示，用带电棒接触原来不带电的验电器的金属球，发现验电器的金属箔张开，下列判断正确的是（）A. 带电棒一定带负电B. 带电棒一定带正电C. 两片金属箔一定带同种电荷D. 两片金属箔一定带异种电荷3.共享单车在车筐底部覆盖着太阳能发电板（如图所示），通过阳光给里面的蓄电池充电，从而为GPS和通信模块供电。
此吋在太阳能发电板和蓄电池的电路中，发电板相当于（）A. 电源B. 用电器C. 导线D. 开关4.如图甲所示是在家庭电路中使用的定时插座。
可以按照我们设定的时间给用电器供电和断电，可供两种插头的移动电器正常使用。
相应参数见图乙，下列说法正确的是（）A. 面板上的两个插座是串联关系B. 不能将功率为2000W的用电器单独接入插座使用C. 插座内只有火线和零线两根导线D. 正常情况下，面板有2个插孔会使检测的测电笔氖管发光5.电阻R1和R2并联，当通过R1的电流为I1时，则通过干路的电流为（）A. B. C. D.6.电脑正常工作时，中央处理器（即CPU）不断发热必须用风扇降温，为保证CPU不被烧坏，CPU工作之前，带动风扇的电动机要先启动，CPU断电后，电动机仍能工作很长一段时间来散热，下列四个电路图符合要求的是（）A. B.C. D.7.如图所示，在研究“电流与电阻的关系”实验中，下列说法正确的是（）①闭合开关前，移动滑片P到最右端是为了起到保护电路的作用②闭合开关后，移动滑片P的作用是控制电阻两端的电压保持不变③闭合开关后，移动滑片P的作用是控制通过电阻的电流保持不变④闭合开关后，移动滑片P的目的是改变电阻两端的电压A. ①②B. ①③C. ①④D. ③④8.如图所示电路中，电源电压保持不变，当变阻器滑片P向右移动时，电表示数变大的是（）A. B.C. D.9.将两个定值电阻接在同一电路中，如果它们两端的电压相等，则下列判断正确的是（）A. 这两个电阻的阻值一定相等B. 通过这两个电阻的电流一定相等C. 若两个电阻并联，相同时间电流通过它们做功一定相等D. 若两个电阻串联，相同时间电流通过它们做功一定相等10.如图为电流表的内部结构图。
2019-2020学年人教新版广东广州市白云区九年级第一学期期末数学试卷 含解析
2019-2020学年九年级第一学期期末数学试卷一、选择题1．方程x2﹣4＝0的解是（）A．x＝2B．x＝﹣2C．x＝±2D．x＝±42．下列图形中，是中心对称图形的是（）A．B．C．D．3．二次函数y＝（x﹣1）2+2的最小值是（）A．﹣2B．2C．﹣1D．14．一枚质地均匀的骰子，它的六个面上分别有1到6的点数．下列事件中，是不可能事件的是（）A．掷一次这枚骰子，向上一面的点数小于5B．掷一次这枚骰子，向上一面的点数等于5C．掷一次这枚骰子，向上一面的点数等于6D．掷一次这枚骰子，向上一面的点数大于65．已知点C为线段AB延长线上的一点，以A为圆心，AC长为半径作⊙A，则点B与⊙A 的位置关系为（）A．点B在⊙A上B．点B在⊙A外C．点B在⊙A内D．不能确定6．两个相邻自然数的积是132．则这两个数中，较大的数是（）A．11B．12C．13D．147．下列抛物线中，其顶点在反比例函数y＝的图象上的是（）A．y＝（x﹣4）2+3B．y＝（x﹣4）2﹣3C．y＝（x+2）2+1D．y＝（x+2）2﹣1 8．如图是一个可以自由转动的转盘，转盘分成黑、白两种颜色指针的位置固定，转动的转盘停止后，指针恰好指向白色扇形的穊率为（指针指向OA时，当作指向黑色扇形；指针指OB时，当作指向白色扇形），则黑色扇形的圆心角∠AOB＝（）A．40°B．45°C．50°D．60°9．一根水平放置的圆柱形输水管横截面如图所示，其中有水部分水面宽8米，最深处水深2米，则此输水管道的半径是（）A．8米B．6米C．5米D．4米10．在下列函数图象上任取不同两点P（x1，y1），Q（x2，y2），一定能使（x2﹣x1）（y2﹣y1）＞0成立的是（）A．y＝﹣2x+1（x＜0）B．y＝﹣x2﹣2x+8（x＜0）C．y＝（x＞0）D．y＝2x2+x﹣6（x＞0）二、填空题（共6小题，每小题3分，满分18分.）11．在平面直角坐标系中，点P（2，﹣3）关于原点对称点P′的坐标是．12．从甲、乙、丙三人中任选两人参加“青年志愿者”活动，甲被选中的概率为．13．已知圆锥的底面半径是3cm，母线长是5cm，则圆锥的侧面积为cm2．（结果保留π）14．如图，△ABC内接于⊙O，∠ACB＝35°，则∠OAB＝．15．若关于x的方程x2+2x﹣m＝0（m是常数）有两个相等的实数根，则反比例函数y＝经过第象限．16．如图，在正方形ABCD中，AB＝a，点E，F在对角线BD上，且∠ECF＝∠ABD，将△BCE绕点C旋转一定角度后，得到△DCG，连接FG．则下列结论：①∠FCG＝∠CDG；②△CEF的面积等于；③FC平分∠BFG；④BE2+DF2＝EF2；其中正确的结论是．（填写所有正确结论的序号）三、解答题[本大飇共9小题，满分102分.解答应写岀文宁说明、证明过程或演算步骤.）17．解方程：x2﹣6x+8＝0．18．如图，在同一平面直角坐标系中，正比例函数y＝2x的图象与反比例函数y＝的图象交于A，B两点，过点A作AC⊥x轴，垂足为点C，AC＝2，求k的值．，∠BAD＝∠CAD．求证：AB＝AC．A B C D E F G H学生垃圾类别可回收物√××√√×√√其他垃圾×√√√√×√√餐厨垃圾√√√√√√√√有害垃圾×√×××√×√（1）检测结果中，有几名学生正确投放了至少三类垃圾？请列举出这几名学生．（2）为进一步了解学生垃圾分类的投放情况，从检测结果是“有害垃圾”投放错误的学生中随机抽取2名进行访谈，求抽到学生A的概率．21．如图，在平面直角坐标系xOy中，A（﹣2，0），B（0，3），C（﹣4，1）．以原点O为旋转中心，将△ABC顺时针旋转90°得到△A'B'C'，其中点A，B，C旋转后的对应点分别为点A'，B'，C'．（1）画出△A'B'C'，并写出点A'，B'，C'的坐标；（2）求经过点B'，B，A三点的抛物线对应的函数解析式．22．为改善生态环境，建设美丽乡村，某村规划将一块长18米，宽10米的矩形场地建设成绿化广场，如图，内部修建三条宽相等的小路，其中一条路与广场的长平行，另两条路与广场的宽平行，其余区域种植绿化，使绿化区域的面积为广场总面积的80%．（1）求该广场绿化区域的面积；（2）求广场中间小路的宽．23．如图，在等边△ABC中，AB＝6，AD是高．（1）尺规作图：作△ABC的外接圆⊙O（保留作图痕迹，不写作法）（2）在（1）所作的图中，求线段AD，BD与所围成的封闭图形的面积．24．已知抛物线y＝x2+（1﹣2a）x﹣2a（a是常数）．（1）证明：该抛物线与x轴总有交点；（2）设该抛物线与x轴的一个交点为A（m，0），若2＜m≤5，求a的取值范围；（3）在（2）的条件下，若a为整数，将抛物线在x轴下方的部分沿x轴向上翻折，其余部分保持不变，得到一个新图象G，请你结合新图象，探究直线y＝kx+1（k为常数）与新图象G公共点个数的情况．25．如图，AB是⊙O的直径，点C是⊙O上一点（点C不与A，B重合），连接CA，CB．∠ACB的平分线CD与⊙O交于点D．（1）求∠ACD的度数；（2）探究CA，CB，CD三者之间的等量关系，并证明；（3）E为⊙O外一点，满足ED＝BD，AB＝5，AE＝3，若点P为AE中点，求PO的长．参考答案一、选择题（共10小題，每小題3分，满分30分.在每小题给出的四个选项中，只有一项是符合题目要求的，）1．方程x2﹣4＝0的解是（）A．x＝2B．x＝﹣2C．x＝±2D．x＝±4【分析】方程变形为x2＝4，再把方程两边直接开方得到x＝±2．解：x2＝4，∴x＝±2．故选：C．2．下列图形中，是中心对称图形的是（）A．B．C．D．【分析】把一个图形绕某一点旋转180°，如果旋转后的图形能够与原来的图形重合，那么这个图形就叫做中心对称图形．解：A、不是中心对称图形，故此选项错误；B、不是中心对称图形，故此选项错误；C、不是中心对称图形，故此选项错误；D、是中心对称图形，故此选项正确；故选：D．3．二次函数y＝（x﹣1）2+2的最小值是（）A．﹣2B．2C．﹣1D．1【分析】考查对二次函数顶点式的理解．抛物线y＝（x﹣1）2+2开口向上，有最小值，顶点坐标为（1，2），顶点的纵坐标2即为函数的最小值．解：根据二次函数的性质，当x＝1时，二次函数y＝（x﹣1）2+2的最小值是2．故选：B．4．一枚质地均匀的骰子，它的六个面上分别有1到6的点数．下列事件中，是不可能事件的是（）A．掷一次这枚骰子，向上一面的点数小于5B．掷一次这枚骰子，向上一面的点数等于5C．掷一次这枚骰子，向上一面的点数等于6D．掷一次这枚骰子，向上一面的点数大于6【分析】事先能肯定它一定不会发生的事件称为不可能事件，据此进行判断即可．解：A．掷一次这枚骰子，向上一面的点数小于5，属于随机事件，不合题意；B．掷一次这枚骰子，向上一面的点数等于5，属于随机事件，不合题意；C．掷一次这枚骰子，向上一面的点数等于6，属于随机事件，不合题意；D．掷一次这枚骰子，向上一面的点数大于6，属于不可能事件，符合题意；故选：D．5．已知点C为线段AB延长线上的一点，以A为圆心，AC长为半径作⊙A，则点B与⊙A 的位置关系为（）A．点B在⊙A上B．点B在⊙A外C．点B在⊙A内D．不能确定【分析】根据题意确定AC＞AB，从而确定点与圆的位置关系即可．解：∵点C为线段AB延长线上的一点，∴AC＞AB，∴以A为圆心，AC长为半径作⊙A，则点B与⊙A的位置关系为点B在⊙A内，故选：C．6．两个相邻自然数的积是132．则这两个数中，较大的数是（）A．11B．12C．13D．14【分析】设这两个数中较大的数为x，则较小的数为（x﹣1），根据两数之积为132，即可得出关于x的一元二次方程，解之取其正值即可得出结论．解：设这两个数中较大的数为x，则较小的数为（x﹣1），依题意，得：x（x﹣1）＝132，解得：x1＝12，x2＝﹣11（不合题意，舍去）．故选：B．7．下列抛物线中，其顶点在反比例函数y＝的图象上的是（）A．y＝（x﹣4）2+3B．y＝（x﹣4）2﹣3C．y＝（x+2）2+1D．y＝（x+2）2﹣1【分析】根据y＝得k＝xy＝12，所以只要点的横坐标与纵坐标的积等于12，就在函数图象上．解：∵y＝，∴k＝xy＝12，A、y＝（x﹣4）2+3的顶点为（4，3），4×3＝12，故y＝（x﹣4）2+3的顶点在反比例函数y＝的图象上，B、y＝（x﹣4）2﹣3的顶点为（4，﹣3），4×（﹣3）＝﹣12≠12，故y＝（x﹣4）2﹣3的顶点不在反比例函数y＝的图象上，C、y＝（x+2）2+1的顶点为（﹣2，1），﹣2×1＝﹣2≠12，故y＝（x+2）2+1的顶点不在反比例函数y＝的图象上，D、y＝（x+2）2﹣1的顶点为（﹣2，﹣1），﹣2×（﹣1）＝2≠12，故y＝（x+2）2﹣1的顶点不在反比例函数y＝的图象上，故选：A．8．如图是一个可以自由转动的转盘，转盘分成黑、白两种颜色指针的位置固定，转动的转盘停止后，指针恰好指向白色扇形的穊率为（指针指向OA时，当作指向黑色扇形；指针指OB时，当作指向白色扇形），则黑色扇形的圆心角∠AOB＝（）A．40°B．45°C．50°D．60°【分析】根据针恰好指向白色扇形的概率得到黑、白两种颜色的扇形的面积比为1：7，计算即可．解：∵指针恰好指向白色扇形的穊率为，∴黑、白两种颜色的扇形的面积比为1：7，∴∠AOB＝×360°＝45°，故选：B．9．一根水平放置的圆柱形输水管横截面如图所示，其中有水部分水面宽8米，最深处水深2米，则此输水管道的半径是（）A．8米B．6米C．5米D．4米【分析】连接OA，作OC⊥AB交AB于C，交圆于D，根据垂径定理求出AC，根据勾股定理列式计算，得到答案．解：连接OA，作OC⊥AB交AB于C，交圆于D，由题意得，AB＝8，CD＝2，∵OC⊥AB，∴AC＝AB＝4，设圆的半径为r，则OC＝r﹣2，由勾股定理得，OA2＝OC2+AC2，即r2＝（r﹣2）2+42，解得，r＝5，即此输水管道的半径是5米，故选：C．10．在下列函数图象上任取不同两点P（x1，y1），Q（x2，y2），一定能使（x2﹣x1）（y2﹣y1）＞0成立的是（）A．y＝﹣2x+1（x＜0）B．y＝﹣x2﹣2x+8（x＜0）C．y＝（x＞0）D．y＝2x2+x﹣6（x＞0）【分析】据各函数的增减性依次进行判断即可．解：A、∵k＝﹣2＜0∴y随x的增大而减小，即当x1＞x2时，必有y1＜y2∴当x＜0时，（x2﹣x1）（y2﹣y1）＜0，故A选项不符合；B、∵a＝﹣1＜0，对称轴为直线x＝﹣1，∴当﹣1＜x＜0时，y随x的增大而减小，当x＜﹣1时y随x的增大而增大，∴当x＜﹣1时：能使（x2﹣x1）（y2﹣y1）＞0成立，故B选项不符合；C、∵＞0，∴当x＞0时，y随x的增大而减小，∴当x＞0时，（x2﹣x1）（y2﹣y1）＜0，故C选项不符合；D、∵a＝2＞0，对称轴为直线x＝﹣，∴当x＞﹣时y随x的增大而增大，∴当x＞0时，（x2﹣x1）（y2﹣y1）＞0，故D选项符合；故选：D．二、填空题（共6小题，每小题3分，满分18分.）11．在平面直角坐标系中，点P（2，﹣3）关于原点对称点P′的坐标是（﹣2，3）．【分析】平面直角坐标系中任意一点P（x，y），关于原点的对称点是（﹣x，﹣y）．解：根据中心对称的性质，得点P（2，﹣3）关于原点的对称点P′的坐标是（﹣2，3）．故答案为：（﹣2，3）．12．从甲、乙、丙三人中任选两人参加“青年志愿者”活动，甲被选中的概率为．【分析】画出树状图，共有6个等可能的结果，甲被选中的结果有4个，由概率公式即可得出结果．解：树状图如图所示：共有6个等可能的结果，甲被选中的结果有4个，∴甲被选中的概率为＝；故答案为：．13．已知圆锥的底面半径是3cm，母线长是5cm，则圆锥的侧面积为15πcm2．（结果保留π）【分析】圆锥的侧面积＝底面周长×母线长÷2．解：底面圆的半径为3cm，则底面周长＝6πcm，侧面面积＝×6π×5＝15πcm2．14．如图，△ABC内接于⊙O，∠ACB＝35°，则∠OAB＝55°．【分析】由同弧所对的圆周角等于所对圆心角的一半，根据∠ACB的度数求出∠AOB的度数，再由OA＝OB，利用等边对等角得到一对角相等，利用三角形内角和定理即可求出∠OAB的度数．解：∵∠ACB与∠AOB都对，∴∠AOB＝2∠ACB＝70°，∵OA＝OB，∴∠OAB＝∠OBA＝＝55°．故答案为：55°15．若关于x的方程x2+2x﹣m＝0（m是常数）有两个相等的实数根，则反比例函数y＝经过第二，四象限．【分析】关于x的方程有唯一的一个实数根，则△＝0可求出m的值，根据m的符号即可判断反比例函数y＝经过的象限．解：∵方程x2+2x﹣m＝0（m是常数）有两个相等的实数根，∴△＝22﹣4×1×（﹣m）＝4+4m＝0，∴m＝﹣1；∴反比例函数y＝经过第二，四象限，故答案为二，四．16．如图，在正方形ABCD中，AB＝a，点E，F在对角线BD上，且∠ECF＝∠ABD，将△BCE绕点C旋转一定角度后，得到△DCG，连接FG．则下列结论：①∠FCG＝∠CDG；②△CEF的面积等于；③FC平分∠BFG；④BE2+DF2＝EF2；其中正确的结论是①③④．（填写所有正确结论的序号）【分析】由正方形的性质可得AB＝BC＝CD＝AD＝a，∠ABD＝∠CBD＝∠ADB＝∠BDC＝45°，由旋转的性质可得∠CBE＝∠CDG＝45°，BE＝DG，CE＝CG，∠DCG ＝∠BCE，由SAS可证△ECF≌△GCF，可得EF＝FG，∠EFC＝∠GFC，S△ECF＝S△CFG，即可求解．解：∵四边形ABCD是正方形，∴AB＝BC＝CD＝AD＝a，∠ABD＝∠CBD＝∠ADB＝∠BDC＝45°，∴∠ECF＝∠ABD＝45°，∴∠BCE+∠FCD＝45°，∵将△BCE绕点C旋转一定角度后，得到△DCG，∴∠CBE＝∠CDG＝45°，BE＝DG，CE＝CG，∠DCG＝∠BCE，∴∠FCG＝∠ECF＝45°，∴∠FCG＝∠CDG＝45°，故①正确，∵EC＝CG，∠FCG＝∠ECF，FC＝FC，∴△ECF≌△GCF（SAS）∴EF＝FG，∠EFC＝∠GFC，S△ECF＝S△CFG，∴CF平分∠BFG，故③正确，∵∠BDG＝∠BDC+∠CDG＝90°，∴DG2+DF2＝FG2，∴BE2+DF2＝EF2，故④正确，∵DF+DG＞FG，∴BE+DF＞EF，∴S△CEF＜S△BEC+S△DFC，∴△CEF的面积＜S△BCD＝，故②错误；故答案为：①③④三、解答题[本大飇共9小题，满分102分.解答应写岀文宁说明、证明过程或演算步骤.）17．解方程：x2﹣6x+8＝0．【分析】先把方程左边分解，使原方程转化为x﹣2＝0或x﹣6＝0，然后解两个一次方程即可．解：（x﹣2）（x﹣4）＝0，x﹣2＝0或x﹣4＝0，所以x1＝2，x2＝4．18．如图，在同一平面直角坐标系中，正比例函数y＝2x的图象与反比例函数y＝的图象交于A，B两点，过点A作AC⊥x轴，垂足为点C，AC＝2，求k的值．【分析】根据题意A的纵坐标为2，把y＝2代入y＝2x，求得A的坐标，然后根据待定系数法即可求得k的值．解：∵AC⊥x轴，AC＝2，∴A的纵坐标为2，∵正比例函数y＝2x的图象经过点A，∴2x＝2，解得x＝1，∴A（1，2），∵反比例函数y＝的图象经过点A，∴k＝1×2＝2．19．如图，在△ABC中，边BC与⊙A相切于点D，∠BAD＝∠CAD．求证：AB＝AC．【分析】根据切线的性质和全等三角形的判定和性质定理即可得到结论．解：∵BC与⊙A相切于点D，∴AD⊥BC，∴∠ADB＝∠ADC＝90°，∵∠BAD＝∠CAD，AD＝AD，∴△ABD≌△ACD（ASA），∴AB＝AC．20．为了创建文明城市，增弘环保意识，某班随机抽取了8名学生（分别为A，B，C，D，E，F，G，H），进行垃圾分类投放检测，检测结果如下表，其中“√”表示投放正确，“×”表示投放错误，A B C D E F G H学生垃圾类别可回收物√××√√×√√其他垃圾×√√√√×√√餐厨垃圾√√√√√√√√有害垃圾×√×××√×√（1）检测结果中，有几名学生正确投放了至少三类垃圾？请列举出这几名学生．（2）为进一步了解学生垃圾分类的投放情况，从检测结果是“有害垃圾”投放错误的学生中随机抽取2名进行访谈，求抽到学生A的概率．【分析】（1）从表格中，找出正确投放了至少三类垃圾的同学即可；（2））“有害垃圾”投放错误的学生有A、C、D、E、G同学，用列表法列举出所有可能出现的结果，从中找出“有A同学”的结果数，进而求出概率．解：（1）有5位同学正确投放了至少三类垃圾，他们分别是B、D、E、G、H同学，（2）“有害垃圾”投放错误的学生有A、C、D、E、G同学，从中抽出2人所有可能出现的结果如下：共有20种可能出现的结果数，其中抽到A的有8种，因此，抽到学生A的概率为＝．21．如图，在平面直角坐标系xOy中，A（﹣2，0），B（0，3），C（﹣4，1）．以原点O为旋转中心，将△ABC顺时针旋转90°得到△A'B'C'，其中点A，B，C旋转后的对应点分别为点A'，B'，C'．（1）画出△A'B'C'，并写出点A'，B'，C'的坐标；（2）求经过点B'，B，A三点的抛物线对应的函数解析式．【分析】（1）分别作出A，B，C的对应点A′，B′，C′即可．（2）设抛物线的解析式为y＝a（x+2）（x﹣3），把B（0，3）代入求出a即可．解：（1）如图△A'B'C'即为所求．A′（0，2），B′（3，0），C′（1，4）（2）设抛物线的解析式为y＝a（x+2）（x﹣3），把B（0，3）代入得到a＝﹣，∴抛物线的解析式为y＝﹣x2+x+3．22．为改善生态环境，建设美丽乡村，某村规划将一块长18米，宽10米的矩形场地建设成绿化广场，如图，内部修建三条宽相等的小路，其中一条路与广场的长平行，另两条路与广场的宽平行，其余区域种植绿化，使绿化区域的面积为广场总面积的80%．（1）求该广场绿化区域的面积；（2）求广场中间小路的宽．【分析】（1）根据该广场绿化区域的面积＝广场的长×广场的宽×80%，即可求出结论；（2）设广场中间小路的宽为x米，根据矩形的面积公式（将绿化区域合成矩形），即可得出关于x的一元二次方程，解之取其较小值即可得出结论．解：（1）18×10×80%＝144（平方米）．答：该广场绿化区域的面积为144平方米．（2）设广场中间小路的宽为x米，依题意，得：（18﹣2x）（10﹣x）＝144，整理，得：x2﹣19x+18＝0，解得：x1＝1，x2＝18（不合题意，舍去）．答：广场中间小路的宽为1米．23．如图，在等边△ABC中，AB＝6，AD是高．（1）尺规作图：作△ABC的外接圆⊙O（保留作图痕迹，不写作法）（2）在（1）所作的图中，求线段AD，BD与所围成的封闭图形的面积．【分析】（1）作BH⊥AC交AD于O，以O为圆心，OB为半径作⊙O即可．（1）线段AD，BD与所围成的封闭图形的面积＝S扇形OAB+S△BOD．解：（1）如图，⊙O即为所求．（2）∵△ABC是等边三角形，AD⊥BC，BH⊥AC，∴BD＝CD＝3，∠OBD＝∠ABC＝30°，∠AOB＝2∠C＝120°，∴OD＝BD•tan30°＝，OB＝2OD＝2，∴线段AD，BD与所围成的封闭图形的面积＝S扇形OAB+S△BOD＝+×3×＝2π+．24．已知抛物线y＝x2+（1﹣2a）x﹣2a（a是常数）．（1）证明：该抛物线与x轴总有交点；（2）设该抛物线与x轴的一个交点为A（m，0），若2＜m≤5，求a的取值范围；（3）在（2）的条件下，若a为整数，将抛物线在x轴下方的部分沿x轴向上翻折，其余部分保持不变，得到一个新图象G，请你结合新图象，探究直线y＝kx+1（k为常数）与新图象G公共点个数的情况．【分析】（1）令抛物线的y值等于0，证所得方程的△＞0即可；（2）将点A坐标代入可求m的值，即可求a的取值范围；（3）分k＞0和k＜0两种情况讨论，结合图象可求解．解：（1）设y＝0，则0＝x2+（1﹣2a）x﹣2a，∵△＝（1﹣2a）2﹣4×1×（﹣2a）＝（1+2a）2≥0，∴x2+（1﹣2a）x﹣2a＝0有实数根，∴该抛物线与x轴总有交点；（2）∵抛物线与x轴的一个交点为A（m，0），∴0＝m2+（1﹣2a）m﹣2a，∴m＝﹣1，m＝2a，∵2＜m≤5，∴2＜2a≤5，∴1＜a≤；（3）∵1＜a≤，且a为整数，∴a＝2，∴抛物线解析式为：y＝x2﹣3x﹣4，如图，当k＞0时，若y＝kx+1过点（﹣1，0）时，直线y＝kx+1（k为常数）与新图象G公共点有3个，即k＝1，当0＜k＜1时，直线y＝kx+1（k为常数）与新图象G公共点有4个，当k＞1时，直线y＝kx+1（k为常数）与新图象G公共点有2个，如图，当k＜0时，若y＝kx+1过点（4，0）时，直线y＝kx+1（k为常数）与新图象G公共点有3个，即k＝﹣，当﹣＜k＜0时，直线y＝kx+1（k为常数）与新图象G公共点有4个，当k＜﹣时，直线y＝kx+1（k为常数）与新图象G公共点有2个，25．如图，AB是⊙O的直径，点C是⊙O上一点（点C不与A，B重合），连接CA，CB．∠ACB的平分线CD与⊙O交于点D．（1）求∠ACD的度数；（2）探究CA，CB，CD三者之间的等量关系，并证明；（3）E为⊙O外一点，满足ED＝BD，AB＝5，AE＝3，若点P为AE中点，求PO的长．【分析】（1）由圆周角的定义可求∠ACB＝90°，再由角平分线的定义得到∠ACD＝45°；（2）连接CO延长与圆O交于点G，连接DG、BG，延长DG、CB交于点F；先证明△BGF是等腰直角三角形，得到BG＝BF，AG＝BF，再证明△CDF是等腰三角三角形，得到CF＝CD，即可求得BC+AC＝CD；（3）过点A作AM⊥ED，过点B作BN⊥ED交ED延长线与点N，连接BE；先证明Rt△AMD≌Rt△DNB（AAS），再证明△AED是等腰三角形，分别求得EN＝+，BN＝，在Rt△EBN中，BE＝，OP＝BN＝．解：（1）∵AB是直径，点C在圆上，∴∠ACB＝90°，∵∠ACB的平分线CD与⊙O交于点D，∴∠ACD＝45°；（2）BC+AC＝CD，连接CO延长与圆O交于点G，连接DG、BG，延长DG、CB交于点F；∴∠CDG＝∠CBG＝90°，∵∠ACB＝90°，∴AC∥BG，∴∠CGB＝∠ACG，∴∠CGB＝45°+∠DCG，∵∠CBF＝90°+∠DCG，∴∠BGF＝45°，∴△BGF是等腰直角三角形，∴BG＝BF，∵△ACO≌△BGO（SAS），∴AG＝BF，∵△CDF是等腰三角三角形，∴CF＝CD，∴BC+AC＝CD；（3）过点A作AM⊥ED，过点B作BN⊥ED交ED延长线与点N，连接BE；∵∠ACD＝∠ABD＝45°，∠ADB＝90°，∴AD＝BD，∵AB＝5，∴BD＝AD＝，∵∠MAD＝∠BDN，∴Rt△AMD≌Rt△DNB（AAS），∴AM＝DN，MD＝BN，∵ED＝BD，∴△AED是等腰三角形，∵AE＝3，∴AM＝，DM＝，∴EN＝+，BN＝，在Rt△EBN中，BE＝，∵P是AE的中点，O是AB的中点，∴OP＝BN，∴OP＝．。
2019-2020广州白云区初三上学期期末物理【试卷+答案】
2019~2020学年广州白云区初三上学期期末物理试卷一、单选题（每题3分，共36分，每题只有一个正确选项）1.A.增大可燃物与空气的接触面B.提高可燃物的着火点C.增大可燃物的热值D.增加空气中氧气的含量古语道：“人要实，火要虚”．此话的意思是说做人要脚踏实地，才能事业有成；可燃物要架空一些，才能燃烧更旺．“火要虚”的目的是（ ）2.A.海边的昼夜温差较小 B.冬天暖气设备用热水供暖C.夏天在室内地面上洒水降温D.用水冷却汽车发动机水具有比热容较大的特点，从而被广泛应用．如图示例中，与此特点的是（ ）无.关.3.A.B.C.D.如图所示，对于图片中所描述的物理过程，下列分析中正确的是（ ）甲乙丙丁图甲，厚玻璃内的空气被压缩时，空气的内能减少图乙，瓶子内的空气推动塞子跳起时，空气的内能增大图丙，试管内的水蒸气推动了塞子冲出时，水蒸气的内能减少图丁，汽缸内的气体推动活塞向下运动时，气体的内能增大4.A.原子核 质子B.原子核 中子C.中子 质子D.电子 中子年底，“悟空”号卫星上的计算机被太空中带正电的某些粒子击中，导致“死机”．在遥控指令下，计算机重新启动，卫星恢复正常，带正电的粒子可能是（ ）5.A.B.C. D.变色二极管红绿交替发光．电流从其端流入时发红光，从其端流入时发绿光．原来其内部封装有一红一绿两个发光二极管，发光二极管符号为，当电流从“”极流入时二极管能通电且发光，当电流从“”极流入时二极管不能发光．则该变色二极管的内部结构可能是下图中的（ ）6.A.B.C. D.如图所示的四个电路中，电压都相等，并且电阻大于，电流表示数最小的是（ ）7.A.B.C.D.如图是探究电流通过导体时产生热的多少跟什么因素有关的实验装置，两个透明容器中密封着等量的空气．开关闭合后，则（ ）左侧容器中导体产生的热量较多图中两导体串联，能探究电热与电流关系若图中两导体改为并联，右侧导体产生的热量较多一段时间后，右侧形管两端液柱高度差较左侧大8.A.拆掉开关，两条导线连在一起B.拆掉开关，两条导线连在一起C.拆掉插座甲，两条导线连在一起D.拆掉灯泡丙，两条导线连在一起图所示为小刚所连的两盏白炽灯和两个插座的电路图．通电后发现不能正常工作．下面几个措施中可能引起危险的是（ ）9.A.B.C.D.判断一个电阻是否能等效替代另外两个串联的电阻，主要看（ ）电路中的电流是否相同电路两端电压是否相等在电路两端电压相等时，电路中的电流是否相同在导体横截面积都相等时，导体的长度是否相同10.A.若接在上，的示数B.若接在上，的示数C.若接在上，示数与示数的比值D.若接在上，示数与示数的比值如图所示的电路中，电源电压保持不变，现将一个电压表接入电路的或两点间．开关闭合后，在滑动变阻器滑片向左移动的过程中，下列数值基本不变的是（ ）11.A.若两灯串联，“”灯泡更亮B.若两灯串联，“”灯泡两端电压更大C.若两灯并联，“”灯泡更亮D.若两灯并联，通过“”灯泡的电流更大将“ ”和“ ”的两个灯泡接在合适的电源上，两个小灯泡均没有烧坏，两灯相比较与实际相符的是（ ）12.A. B. C. D.如图所示，电源电压保持不变，在甲、乙两处分别接入电压表（电压用、表示)，闭合开关，测得．断开开关，拆去电压表，并在甲、乙两处分别接入电流表（电流分别用、表示)，此时是（ ）甲乙甲乙甲乙甲乙二、填空、作图题（共22分）13.海洋中有一种会放电的鱼叫电鳐，它放电时最高电压可达，即为 ，游近电鳐的鱼会被电死或电晕，因为海水是 （选填“导体”或“绝缘体”)．14.如图中甲、乙所示是试触和正确测量电流的过程电流表指针指示位置，则对应的图丙试触时连接的是电流表的“ ”接线柱，准确测量通过灯泡的电流是 ．15.如图所示是某型号灯泡的宣传广告．表示这个灯泡与“”白炽灯在正常工作时的 （选填“电功率”或“亮度”）大致相等，度电可供“”白炽灯正常工作 小时．16.12（1）（2）物理课上，老师给同学们出示了一个有盖的木盒，先断开开关，后在盒盖上插入两只灯泡到灯座（导线的连接情况隐藏在盒内），如图所示．当老师闭合开关时，两只小灯泡都亮了；断开开关，两灯泡又同时熄灭．请你判断：在这个木盒内，除了导线，一定还有另外一个电路元件，它是 ．根据上述现象：你 （选填“能”或“不能”）断定这两只小灯泡是串联的．经过检验，这两只灯泡确实是串联的，但在老师闭合开关的时候，细心的小华观察到灯比亮些．她认为这是因为比更靠近电源正极的缘故．在不增加其他器材的条件下，能证实小华的判断是否正确的做法是 ．17.（1）（2）学校实践活动小组的同学想检测一块旧式电能表是否准确电能表表盘如图所示．只有一个接入电路的用电器，功率为．理论计算：让用电器连续工作后电能表示数应为：实验测量：使用该用电器正常工作测出表盘转过转，则消耗的电能是 ．18.（1）（2）如图所示为家庭电路的基本组成，、两个方框位置的两个电路元件分别是电能表和总开关．在两个方框位置安装总开关的是 （选填“”、“”）．图中的三孔插座已经按安全用电要求接线，请将图中灯泡和二孔插座按安全用电要求连入电路，要求开关只控制灯泡，且电路能正常工作．19.（1）（2）小明利用如图所示的电路检验并联电路干路电流是否等于各支路电流之和，其中几根导线接错了．按如图的实物图在右边虚线框内画出对应的电路图．在图中将接错的导线打上“”，然后重新画上导线，使实物图能达到实验目的．三、解析题（共19分）20.（1）（2）（3）电源电压保持不变，如图甲所示，当开关从点转到时，电流表和电压表对应的两组数据在如图乙描点，由图甲和图乙提供的的信息求：电源电压．的阻值．的阻值．21.（1）（2）（3）（4）如图所示为某品牌电热开水壶及其铭牌，当水烧开时温控开关自动断开停止加热如果这段时间内，电热开水壶正常工作，恰能将、的水烧开（气压为标准大气压，），求：正常工作时通过电热水壶的电流（保留小数点后一位）．此过程消耗的电能是多少？此过程中水吸收的热量？电热开水壶的效率是多少？水四、实验、探究题（共23分）22.（1）A.小灯泡断路B.小灯泡短路C.滑动变阻器断路D.滑动变阻器接入电路的阻值过大（2）（3）（4）小明想测量标有“”字样小灯泡的电阻，已经正确设计电路图．（未画出）请用笔画线代替导线，将图中的实物电路连接完整．（导线不能交叉）闭合开关后，发现电流表、电压表的指针均有偏转．但灯泡不亮，原因可能是（ ）调节滑动变阻器，不用改变电表的量程，测得实验数据如表所示：实验次数第次第次第次第次电压（）电流（）电阻（）在分析实验数据时，发现一个数据有明显的错误，这个数据是 ；若此错误是看错电表量程导致的，则该数据的正确值应是 ．根据实验数据可知，小灯泡正常发光时的电阻是 ．23.（1）（2）小玲同学在做多个电学实验时，发现都用到了如图的两个电路图，其中都有滑动变阻器，于是她在不同的实验中，通过分析比较，对滑动变阻器的作用进行了归纳总结．实验前滑动变阻器都应该调到 ，让滑动变阻器起到 的作用；在探究欧姆定律的实验时，应该选择图中的 电路进行实验，而不选另一个电路的原因是因为 ；先探究导体中的电流与导体两端的电压关系时，滑动变阻器的作用是；再探究导体中电流与导体的电阻关系时，要调节滑动变阻器，此时其作用是 ．24.（1）（2）如图所示的甲、乙液体，质量和温度都相同，为了比较它们的比热容大小．请你设计实验方案：还需要增加的实验器材有： ．写出实验步骤（可画图说明）和比较比热容大小的方法．2019~2020学年广东广州白云区初三上学期期末物理试卷(答案)一、单选题1.A2.C3.C4.A5.B6.D7.D8.D9.C10.C11.A12.B二、填空、作图题13. ; 导体14. ;15.亮度 ;16.12（1）（2）电源或电池或电池不能断开开关，将两灯位置互换，观察闭合开关后是否变暗17.（1）（2）18.（1）（2）19.（1）（2）三、解析题20.（1）（2）（3）21.（1）（2）（3）（4）四、实验、探究题22.（1）（2）（3）（4）D;。
九年级试题—2018-2019学年广东省广州市白云区九年级(上)期末英语试卷及试题解析
2018-2019学年广东省广州市白云区九年级(上)期末英语试卷一、语法选择(共1小题；每小题15分，满分15分)阅读下面短文，按照勺子结构的语 法性和上下文连贯的要求，从1〜15各题所给的A 、B 、C 和D 项中选出最佳选项，并在答 题卡上将该项涂黑1. ___________________________________________________________________ (15 分)Do you like reading stories? Maybe you will answer, No, I am not (1) __________________ childany more! H Yes, children all over the world always love stories ・Chinese children are (2) ______ i n Monkey Kings story. Il has been a popular bedtimestory in China (3) _______ many years ・ In fact, adults (4) __________ l ove the story a lot. For them, Monkey King has become a very unforgettable part in the memory of (5) childhood ・ The clever and humorous monkey (6) ___________________________ the hearts of many Chinese people ・ British boys and girls all know Alice*s Adventures in Wonderland (7) ________ ・ As the name shows, it's a story full of dangerous (8) ___________ exciting trips ・ Children laugh, cry and even get frightened with Alice together while (9) __________ t he story. Most American kids have read The Adventures of Tom Sawyer, by the famous writer, Mark Twain. Everyone likes the brave boy (10) ____________________________ also has lots of risks ・ Some scenes of the story may make your heart (11) _________ faster, for Tom and his friends meet some very bad men and (12 ) ______ usually in danger ・ Of course in the end, they beat the bad ones ・You( 13) ___ also ask me if I like stories ・ Yes, I have liked them since I was veryyoung. At that time, I often (14) _________ all my pocket money on storybooks For ne, stories are much (15) _______ than chocolate! They help me learn a lot. So either young or old, lei's enjoy stories.(1) A. a B. an C. the D ・ /.(2) A. interestB. interestingC.interestedD ・ interestingly (3) Aon B. for c. at D ・ of (4) A. too B. also c. either D ・ as well (5) A.they B.themc.theirD・themselves(6) A. wins B. will win c. winD・is winning(7) A. good B. better C. best D・well(8) A. nor B. so C. or D・but(9) A. read B. reading c. to read D・to reading(10) A. who B. which c. what D・when(11) A. go B. goes c. going D・went(12) A. is B. was c. are D・were(13) A. need B. can c. should D・may(14) A. spend B. spent c. will spend D・have spent(15) A. delicious B. more delicious c. most delicious D・deliciously二完形填空(共1小题；每小题1・5分，满分15分)阅读下面短文，掌握大意，然后从16〜25各题所给的A、B、C、D项中，选出最佳选项，并在答题卡上将该项涂黑.2.(15 分)A blind boy sat on the steps of a building with a hat beside his feet. He held a sign which said,H I am blind. Please (1) ______________________ me. HThere were only a few coins in the (2) _________ ・A man was walking by. He took out a few coins from his wallet and dropped them into thehat. Hethen took the sign, tuned it around» and (3) __________ some words on it. he put the sign back so that everyone who walked by could see the new (4) ________ ・Soon the hat began to fill up. A lot more people were (5) _________ money to the blind boy. That afternoon the man who had changed the sign came to see how things were The boy recognized (认出)his footsteps and asked> N Are you the one who changed (6) ___________ sign in the morning・ What did you write? ”The man said, only wrote the (ruth. I said what you said, but in a different way. M H What he had written was, ”Today is a beautiful day, but I can't see it.Both signs told people the boy was (7) _______ ・ But the first simply told people to help by puttingsome (8) _______ in the hat. The second sign told people that they were able to enjoy thebeauty of the day but the boy could not enjoy it because he was blind.There are (9) _______ two lessons we can learn from this simple story. The first is：Be thankful for what you have ・ Somebody else has less ・ Try your best to help those whoneed your help・ The second is： Be creative・ Think (10 ) ________ ・ There is always a better way.(1)A. call B ・ help C・choose D. praise(2) A. bag B ・ wallet C・box D. hat(3) A. wrote B・ printed C・leant D. cleaned(4) A. ways B ・ stories C・words D. pictures(5) A. accepting B ・ receiving C・borrowing D. giving(6) A. her B・ his C・my D. your(7) A. kind B・ deaf C・clever D. blind(8) A, coats B, biscuits C・coins D. gifts(9) A. at least B ・ at last C・at once D. at first(10) surprisedly B ・ differently C・wonderfully D. warmly三.阅谟(烘两节.满分4()分)第一节阅读理解(共4小题；每小題2分，满分40分) 闷读下而短文、掌握大意，然后从26〜45各题所给的A、B、C、D项中，选出最佳选项，并在答題卡上将项涂黑.3.(10 分)My parents seldom encouraged me to ask for help, so I trained myself to become asindependent as possible ・I thought if I asked for help • I would be a problem to other people ・I walked into the supermarket near my house, not buying anything・ I just wanted to staythere quietly. The pain of losing my husband was still too great. And this supermarket held so many sweet memories.He often came with me・ and almost every time he'd pretend to go off and look for something special. He always bought me yellow roses・ He knew I loved roses・Now, standing by the meat, I searched for the perfect small steak because my husband used to loveSteak.Suddenly a woman came up beside me I watched as she picked up a large pack of T - bone steaks dropped them in her basket, hesitated (犹豫不决)，and then put them back.She saw me watching her・ and she smiled H My husband loves T - bone steaks, but they*re so Expensive ・NM My husband passed away eight days ago H I told her ・ I fought to control the sadness in my voice ・Buy him the T - bone steaks And cherish every moment you have together ・HSurprised by my words > she placed the T - bone steaks in her basket and walked away silently. However> several minutes later that woman came towards me again. In her arms she carrieda package ・ On her face was the brightest smile I had ever secn.As she came closer, I saw what she held, and I couldn't hold back my tears・"These are for you, M she said and placed three beautiful yellow roses in my hands・ I wanted to tell her what the roses meant for me, but» still unable to speak・ I watched as she walked away.I looked down at the beautiful roses・ How did she know? Suddenly the answer seemed soclear ・ I wasn't alone・ There were still many people caring for me and willing to help me ・Just be thankful for what you have and who you arc.(1)The author went to the supennarket because ______ ・A・she wanted to buy some foodB・there were many sweet memories for herC・the roses there were much nicerD・her friend was waiting for her(2) What did the woman give the author?A・Some yellow rosesB・Some beautiful picturesC・A pack of T - bone sicksD・A bowl of ice - ercam(3)According to the text» we know the woman was ________A. a strangerB ・ a friend of the authorC・ a friend of the authors husbandD・ the manager of the supermarket（4）________________________________________________________ W hat kind of feeling did the author have towards the woman? _________________________________A. PitifulB. CriticalC. ThankfulD. Fearful（5）___________________________________ What does the author want to tell us?A.Making friends is very important・B ・ Cherish what we haveC.Don't forget people who have diedD.Helping others is not necessary4.（10 分）Carl visited his grandparents on their farm・ He was given a slingshot （弹弓）to playwith in the woods・ He was excited and practiced for some time ・ But he could never hit the target （靶子）.Getting a little upset, he went back for dinner・ As he was going back, he saw his grandma's duck ・Without thinking♦ he used the slingshot to hit the duck in the head and killed iL_In a panic （惊慌）,he hid the dead duck in the woodpile （柴堆），only to see his sister watching ! ButSally said nothing ・After lunch the next day, Grandma said, ”sally, help me with the dishes・MBut Sally said「Grandma> Carl told me he wanted to help in the kitchen：H Then she whispered （低声）to Carl, M Remember the duck? So Carl did the dishes.Later that day, Grandpa asked if the children wanted to go fishing, and Grandma said, M rm sorry but I need Sally to help me make supper・nSally just smiled and said, ”Well, that's all right because Carl told me he wanted to help you.Shewhispered again, Remember the duck? HSo Sally went fishing and Carl stayed behind to help make supper・After several days of doing both his chores and Sally's, Carl finally couldn't stand it anymore ・ He went to his grandma and said that he had killed the duck・Grandma gave him a hug, and said, "Sweethearts I know・ You see, I saw the whole thing at the window the day , but because I love you, I forgave you. I just waited to find out when you would tell me what you did, n(1) What does the underlined word H it in paragraph 2 refer to? ___________A. The slingshotC. The duck.B. The targetD. The head(2 ) Who actually saw Carl hit the duck?A. His parentsB. Only his sisterC. Only his grandmaD. His sister and grandma(3)What did Carl do after he hit the duck? _______A.He ate the duckB.He hid the duckC.He gave the to sally.D.He gave the duck to his grandparents(4)Why did Carl keep helping Sally do chores? _______A. Because he had told her he would do themB・ Because Sally didn* t know how to do themC・ Because he wanted sally to keep the secretD・ Because Grandma asked him to do the chores ・(5)What has Carl learned from his experience? _______A. One should be braveB・ One should be honest.C・ One should be helpfulD・ One should be pat5.（10 分）Alix cried with joy during his graduation at West point （西点军佼）.His unusual journeyis what makes his moment truly special.Alix had a reason to cry In seven years, he went from speaking basic English in a poor community to graduating from one of the best military （军事的）and educational institutions （机构）in the United States ・When he was very young, Alix was very interested in Planes・ And the dream of becominga pilot changed him forever・”people where F m from don't grow up to be pilots・ Thai's not something you do, said Alix."Youdont just say I'm going to be a pilot and make it happen. HSo how did he achieve his dream? What drove him into West Point? What drove him to the top of his class?It's his father, Dieujuste. who has played the important role in his success・ To care for his own family, Dieujuste dropped out of school at 14, leaving his home to find work・ Like anyparents• the father wanted his children to have the opportunities （机会）that he didn't have.Alix said, M My dad always said that education was the only gift he could give us, because he didn *t have anything material to give ・HDriven by his father's encouragement to use education and high marks as a ticket to a better life, Alix spent his teenage years as a hard - working student.H At this moment, three things came to my mind and led to those tears, ”Alix explained・H The first is where I started・ The second is where I am. The third is my future・”（1） What happened during Alix*s graduation? _____A ・ He couldn't help cryingB ・ He spoke basic EnglishC・ He didn't get there on timc.D ・ He set out on a new journey(2)According to the fourth paragraph> people from Alix's hometown might think his dreamis ____ ・A・ interestingB.boringC・ crazyD・ small(3)We can see Alix's father _____ ・A. had an easy and rich lifeB ・ supported his son's dreamC・ received a good educationD・ gave Alix many material gifts(4)All of the following statements are true EXCEPT that _______ ・A. Alix is interested in planesB・ Alix used to be not good at EnglishC.Alix works hard to realize his dreamD・ Alix once dropped out of school(5)What is the best title for this passage? ______A. Don11 Laugh at OthersB ・ Care for Your familyC ・ Never Give up on Your DreamsD・ Money Is More Important Than Education6.(10 分)According to a new reports the cost of living has been rising around the world in recent years・ In the study, researchers surveyed 214 cities worldwide・ So, which cities are the most expensive to live ? Tokyo ♦ Japan ・Tokyo is one of the most expensive places to live ・ There are also two other Japanese citiesthat have made the top 10 list this year：Osaka and Nagoya・The cost af goods like a cup of coffee, fuel and a fast ・ food meal in Tokyo has gone up over the past year.B ・ TwoC. ThreeD・ Four(2 ) Which place is the cheapest to live in among the cities surxeyed? ________A. OsakaB・ Hong KongC・ Singapore ・D・ Karachi(3)In which place is the rent for a luxury 2 - bedroom apartment the cheapest? ________A. Hong KongB. SingaporeC. TokyoD. Osaka(4)Which of the following statements is NOT tnie? _______A. Compared to Singapore♦ buying a car in Hong Kong is more expensive・B・ Hong Kong has made the top 10 list in the survey.C・ a daily international newspaper in Singapore is cheaper than that in Hong KongD・ Too many foreigners moving in Singapore is the biggest factor in pushing up the cost of living there(5)Where does the passage probably come from? ______A. a building websiteB ・ A fashion magazine ・C. A surv r ey report ・D・ Textbook.第二节阅读填空(共1小题；每小题5分，满分5分)阅读短文及文后选项，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑7.(5 分)Chinese people love the color red・ They regard red as a symbol of energy, happiness andgood luck・(1) _________ By wrapping (包裹) money in red packets, it is hoped that theywill bring more happiness and blessings (祝福)to the receivers・(2) __________ However, it is impolite to open a red packet in front of the person who gives it to you.Red packets are usually given on holidays such as the Spring Festival as well as on special days such as weddings ・ The amount of money in the red packets is often an even number （偶数）. For example» six and eight are lucky numbers for Chinese people・（3）・ Thepronunciation of the word v four H,sounds like H death n in Chinese・ That'sa symbol of bad luck・（4） ___ Folding the money or giving dirty bills is bad manners・ Theamount of money you wrap in the red packets depends on how much you earn ・（5）___ However, there is a custom in some places that if you are not married you don'tneed to give red packets to others・ Your close relatives will keep giving you red packets even though you are married・ They are a symbol of their love and blessings to you.A. The money in the red packets should always be newB・ Giving people red packets is a way for offering good wishesC・ When giving or receiving a red packet ♦ it is polite to use both handsD・ There is also a tradition that the number four should not appear in the amountE・ Generally speaking, if you start earning money, it is time to give red packets四、写作（共三节；满分6分）笫一节单词拼写（共6小题；每小题1分，满分6分）根据下列句子及所给单词的首字母写出所缺单词.在填写答卷时，要求写出完整单词.（每空只写一词）8.（1 分）It was a m ___ to go by bus - the journey took two hours!9.（1 分）I work hard because I don't want to f ____ my Maths test.10.（1 分）Are you ill? You look p ______ ・11 ・（1 分）--How much did the book c ______ ?--Five yuan ・12.（1 分）Keep s ____ while the dentist looks at your teeth.13.（1 分）--Let*s make a d _______-・ I'll help you today if you help me tomorrow.笫二节完成何子（共7小题；每小题2分，满分14分）根据所给的汉语内容，用英语完成下列句子.（每空限填一词）14.（2分）我已把这首诗背下来.I have learned the poem ___________ ・15.（2分）我很久没有收到吉尔的信了.It's ages since I ___________ Jill.16.（2分）汤姆到处找车钥匙，但找不到.Tom __________ the key to the bike but he couldn *t find it.17.（2分）她成为一名飞行员的梦想即将实现Her dream ____________________ will come tnie.18.（2分）臭豆腐吃起来美味.The smelly tofu __________ .19.（2分）我想知道我们寒假什么时候开始？I wonder ____ our winter holiday ___________ ・20.（2分）考试过后，小林觉得真放松啊！__________ Xiao Lin felt after the exam!笫三节书面表达（共1小题；满分15分）21.（15分）张涵的笔友Tim在数学课上回答了同学的一个问题，老师误认为他们在聊天而批评了他们.Tim觉得不公平，从此在数学课上紧张不安，也不喜欢这位老师的课了.但Tim很希望能把数学学好，不知如何是好的他写了封邮件向张涵咨询意见.假设你是张涵，根据以下要点提示给Tim回信.字数80左右，信开头已给出，不汁入总词数，可适当发挥.要求：1.每个老师都想他的学生努力学习；2.我认为你应该与数学老师谈谈，告诉他真相：3.他会理解你的，并为你想学好数学感到高兴：4.你应该知道老师所做是为你好：5.……（至少补充两点.）参考词汇：focus on聚焦…Dear Tim,I am sorry that you are having difficulty with your Maths class.Wish you have a better life!YoursZhang Han2018-2019学年广东省广州市白云区九年级（上）期末英语试卷翁考答案与试題解析一、语法选择（共1小题；每小题15分，满分15分）阅读下面短文，按照勺子结构的语法性和上下文连贯的要求，从1〜15各题所给的A、B、C和D项中选出最佳选项，并在答题卡上将该项涂黑1.【解答】1. A.考查冠词.本题涉及是否使用冠词和使用哪个冠词的问题.child是可数名词，故用a来修饰，表示“一个（孩子）”.句意：我不再是个孩子了.故选A.2. C.考査形容词.四个选项分別是interest的划词（动词原形）、动名词、形容词和副词形式.根据语境可知，中国儿童对孙悟空的故事很感兴趣.be interested in对……感兴趣.故选C.3. B.考查介词.on在……上面;for为了；at在:of……的.根据语境可知,在中国，多年来，它已经成为很受欢迎的催眠故事• for many years多年来.故选B.4. B.考查副词（介词短语）.四个单词（短语）都是”也"的意思，但是它们所用的句式和在句中的位置不同.too, also和as well用于肯定句,而either用于否定句.also用于实义动词之前或助动词、情态动词之后：too和as well—般用于句末.由上可知，also 符合语境.句意：事实上，成人也很喜欢这个故事.故选B.5. C.考查代词.四个选项分别是they的主格、宾格、形容词性物主代词和反身代词.空格处为龙语，故选形容词性物主代词.句意：对他们来说，孙悟空已经成为他们儿童时代记忆中一个非常难忘的部分.故选C.6. A.考查动词.四个选项分別是win的三单、一般将来时、原形和现在进行时.根据语境可知，聪明幽默的猴子贏得了中国人的心.本句说的是现在的事实，故用一般现在时，故选三单形式.故选A.7. D.考査副词和形容词.good好的：better更好：best最好；well很好.根据语境可知，英国男女生都很了解《爱丽丝梦游仙境》，空格处为状语，故用副词well充当.故选D.8D.考查连词.nor也不；so因此：or或者but但是.根据语境可知，正如划字所显示的，它描述了一个充满危险但是令人激动的多次旅行的故事.故选D.9. B.考查动名词.四个选项分別是read的动词原形、动名词、不泄式和”to+动划词” 形式.空格处为介宾，故应用动划词来充当宾语.句意：孩子们在读这个故事的时候，和爱丽丝一起笑、哭、甚至担惊受怕.故选B10. A.考查关系代词（副词）.who谁：which哪个（哪些）；what什么：when何时.空格处为泄语从句的主语，代指boy,故用who来引导立语从句.句意：大家都喜欢那个也有很多冒险经历的勇敢男孩.故选A.11. A.考查动词.四个选项分别是动词go的原形、三单、动需词（现在分词）和过去式.本句是"make sb do sth”句型,意思是”使某人做某事",故填动词原形.句意：故事的一些场景会使你心跳加速.故选A.12. C.考查动词.四个选项分别是be的某种形式.空格处和前而的meet是并列成分，故填be的一般现在时复数形式（arc）.本句用一般现在时叙述，显得生动形象.句意：因为汤姆和他的朋友遇到很多坏人，并且通常处于危险境地.故选C.13. D.考査情态动词.need需要；can能够（可能）；should应该;may可能（也许）.根据语境可知，你也许会问我是否喜欢故事.空格处表示猜测，意思是”也许；可能”，故用may表示猜测语气.故选D.14. B.考查动词.四个选项分别是动词spend的原形、过去式（过去分词）、一般将来时和现在完成时.根据时间状语"At that time"可知，本句说的是过去之事，故用一般过去时.句意：那时，我常常把所有零钱用来买故事书.故选B.15. B.考査形容词.delicious美味的；more delicious更加美味的：most delicious最美味的：deliciously美味地（芬香地）.根据句中的than可知，本句是比较句，故用比较级more delicious.句意：对我来说，故事书比巧克力更美味.故选B.二、完形填空（共1小题；每小题1.5分，满分15分）阅读下面短文，掌握大意，然后从16〜25各题所给的A、B、C、D项中，选出最佳选项，并在答题卡上将该项涂黑.2.【解答】1. B考查动词.A呼呼：B帮助：C选择：D奖励；根据上句I am blind我是肓人，应该是帮助我，故答案是B.2.D考査名词.A包：B钱包：C盒子；D帽子;根据前W with a hat beside his feet脚边有个帽子，应该是放到帽子里，故答案是D.3.A考查动词.A写：B E卩刷；C学习：D打扫；根据后而some words on it应该在上写一些词，故答案是A.4.C考查名词.A方式；B故事；C词：D照片：根据could see the new应该是能看到人.故选C・(5) B.主旨大意题•根据Just be thankful for what you have and who you are・只要感谢你拥有的和你是谁.可知作者想要告诉大家要珍惜自己拥有的.故选B.4.［解答］(1) B・词义猜测题•根据Without thinking> he used the slingshot to hit the duck in thehead and killed i(.他没有想到，就用弹弓击中了头部的鸭子并杀了它.故选B.(2) D.细节理解题•根据In a panic (惊慌)，he hid the dead duck in the woodpile (柴堆)，only to see his sister watching !--Grandma gave him a hug, and said, ^Sweethcartt I know. You see, I saw the whole thing at the window the day ,惊慌失措，他把死鸭藏在柴堆里，只看到他的妹妹在看！…奶奶给了他一个拥抱，然后说道，”甜心，我知道.你看，我看到了那一天在窗口的整个事情，故选D.(3)B・细节理解题•根据In a panic (惊慌)，he hid the dead duck in the woodpile (柴堆)，惊慌失措，他把死鸭藏在柴堆里，故选B.(4)C・细i'j理解题.根据After several days of doing both his chores and Sally's, Carl finallycouldift stand it anymorc. He went to his grandma and said that he had killed the duck.经过几天做家务和莎莉之后，卡尔终于忍不住了.他和奶奶说，他杀了鸭子.可知之前答应莉莎是因为想让她保守秘密.故选C.(5) B.主旨大意题.根据Grandma gave him a hug, and said, M Sweethearts I know. You see, I sawthe whole thing at the window the day , but because I love you, I forgave you. I just waited to find out when you would tell me what you did,H奶奶给了他一个拥抱，然后说， "亲爱的，我知道.你知道，那天我在窗口看到了整件事，但是因为我爱你，我原谅了你•我只是等着找你什么时候告诉我你做了什么，”可知一个人应该诚实.故选B.5.【解答】(1) A・细节理解题.根据Alix cried with joy during his graduation at West point(西点军佼).Alix在西点军校毕业时髙兴得哭了起来.故选A.(2)C・推断题•根拯”people where V m from don't grow up to be pilots. That's not somethingyou do,"我家乡的人不会长大成为飞行员.这不是你做的事情.可知他们会认为Alix是疯狂的.故选C.(3)B・细巧理解题.根据So how did he achieve his dream? What drove him into West Point?What drove him to the top of his class? It's his father> Dieujuste, who has played the important role in his success・那么他是如何实现自己的梦想的呢？是什么驱使他进入西点军校？是什么让他成为班上的佼佼者？他的父亲Dieujuste 他的成功中发挥了重要作用.故选B・（4）B・细节理解题.根据Alix had a reason to cry In seven years, he went from speakingbasic English in a poor community to graduating from one of the best military （军事0勺）and educational institutions （机构）in the United States. Alix 有理由哭泣七年来,他从一个贫穷的社区讲基础英语，到美国最好的军事机构毕业.可知文中并不是说Alix不擅长英语.故选B.（5） C.主旨大意题.通读全文，可知本文主要是讲Alix是如何在一个非常困难的环境中最终还可以实现自己的梦想的故事，故选用”从不要放弃你的梦想”为题合适.故选C.6.【解答】1 ・ C 细节理解题•根拯Tokyo is one of the most expensive places to live. There arealso two other Japanese cities that have made the top 10 list this year： Osaka and Nagoya・东京是最昂贵的居住场所之一，还有另外两个日本城市今年跻身前十名：大阪和劣古屋.可知，在调查中，有3个日本城市排在前10名.故选C.2・ D 细节理解题.根据Now, Tokyo is about one - third more expensive than Karachi> which is the least expensive city among the 214 cities.可知，在被调查的城rb•中，Karachi 的物价是最便宜的.故选D.3・B 细节理解题.根据Singapore：u However»its average monthly rent for a 2 - bedroom apartment is much lower than that in the above three Japanese cities”. ”然而，它的两居室月租金却远低于上述三个日本城帀.”可知，新加坡的一个豪华的两居室公寓的租金是最便宜的.故选B.4. A 推理判断题.根据Hong Kong, the only Chinese city to make the top 10 list, has beenranked the ninth most expensive place to live ・ The average monthly rent for a 2 - bedroom apartment Jumped by around US $ 1, 300・ With a limited housing supply♦ the average house prices in Hong Kong have risen sharply by over 93 percent in recent years ・香港是中国唯一一个跻身前10名的城市，被列为第九个最昂贵的居住地.一套两居室公寓的月租金平均上涨了1, 300左右.在有限的住房供应下，香港的平均房价近年来急剧上升了93% 以上.可知文章中没有提到香港买一辆车多少钱.故选A.5. C 推理判断题.根据According to a new report, the cost of living has been rising around theworld in recent years・ In the studyt researchers surveyed 214 cities worldwide・ Hi据一份新的报告，近年来世界各地的生活成本一直在上升.在这项研究中，研究人员调查了全球214个城市.可知，本文讲述的是在各个地区的花费调查，所以是一份调查报告.故选c.第二节阅读填空（共1小题；每小题5分，满分5分）阅读短文及文后选项，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑7.【解答】细节理解题.1. B 根据后句By wrapping （包裹）money in red packets, it is hoped that they will bring morehappiness and blessings （祝福）to （he receivers.用红色包装的钱，希望能给接受者带来更多的幸福和祝福.可知结合选项，应说给人们红包是表达良好祝愿的一种方式.故选B.2. C 根据后句However, it is impolite to open a red packet in front of the person who gives it toyou.然而，在给你的人而前打开红色包装是不礼貌的.可知结合选项，应说当送红包或收红包时，用双手是礼貌的.故选C.3. D 根据后句The pronunciation of the word"four"'sounds like "death"in Chinese. That's a symbolof bad luck. ”4"这个词的发音在汉语中听起来像”死亡”.这是坏运气的象征.可知结合选项，应说还有一个传统，数字4不应该出现.故选D.4. A 根据后句Folding the money or giving dirty bills is bad manners.叠钱或给脏钞票是不礼貌的.可知结合选项，应说红包里的钱应该是新的.故选A.5. E 根据后句However, there is a custom in some places that if you are not married you don't needto give red packets to others.然而，有些地方有一种习俗，如果你不结婚，就不需要给别人红包.可知结合选项，应说一般来说，如果你开始赚钱，是时候给红包了.故选E.四、写作（共三节；满分6分）笫一节单词拼写（共6小题；每小题1分，满分6分）根据下列句子及所给单词的首字母写出所缺单词.在填写答卷时，要求写出完整单词.（每空只写一词）8.【解答】mistake考查名词.根据下文"这次旅程花了两个小时”，推断说话人抱怨旅程时间太长，觉得不应该乘坐公交车去.由冠词a和首字母m考虑mistake的单数形式. 故答案为:mistake9.【解答】根据意思：我努力学习是因为我不想数学考试不及格.want to do想要干某事，故填动词原形fail.故答案是:fail.10.【解答】根据意思：你病了吗？你脸色苍白.look系动词，后而加形容词.故答案是：pale.11.【解答】考查动词.根据答语"五元"推断此处是询问买这本书花了多少钱？由首字母c考虑cost,由助动词did推断此处用动词原形.故答案为cost12.【解答】考查形容词.根据语境"当牙医在给你看牙时"，推断不能说话，保持安静.keep 用作连系动词时，与后而的形容词构成系表结构，意为”保持某种状态”.keep silent意为 "保持安静”.故答案为silent13.【解答】考查名词.根据答语”如果明天你帮助我，今天我就会帮助你”，推断两人是达成某项交易.make a deal是短语，意为”成交：达成交易".故答案为deal笫二节完成何子（共7小题；每小题2分，满分14分）根据所给的汉语内容，用英语完成下列句子.（每空限填一词）14.【解答】根据题干，可知需要翻译的是"记牢“，苴英文表达方式是"by heart",结合句意：我已把这首诗背下来.故答案为by heart.15.【解答】根据题千，可知需要翻译的是”收到…的来信“，其英文表达方式是” hear from",since引导一般过去时的句子，结合句意：我很久没有收到吉尔的信了.故答案为heard from.16.【解答】根据题干，可知需要翻译的是"寻找"，其英文表达方式是"look for "，时态为一般过去时，结合句意：汤姆到处找车钥匙，但找不到.故答案为looked for.17.【解答】根据汉语提示：她成为一名飞行员的梦想即将实现.9do不泄式作后宜左语. 故答案是：to , be , a , pilot.18.【解答】此题根据汉语：臭豆腐吃起来美味.一般现在时态，主语是单数第三人称，故用tastes, taste是系动词，故后面加形容词.故答案是：tastes , good.19.【解答】答案：when, will start根据句意，要用一般将来时，英构成是will +动词原形，这是一个含有宾语从句的复合句.什么时候when,开始start,放在will后而用动词原形，故答案为when, will start20.【解答】根据题干，可知需要翻译的是厂‘，其英文表达方式是” S结合句意：考试过后,小林觉得真放松啊！故答案为After exam.笫三节书面表达（共1小题；满分15分）21・【解答】Dear Tim,I am sorry that you are having difficulty with your Maths class.（表示安慰）I think every teacherwants his students to work hard.【高分句型一】They want their students to be better. And they are always proud of their students.（老师对学生的态度）So I think you should talk to your math teacher and tell him the truth・ I'm sure he will understand you. He will be pleased if you want to learn math well.［高分句型二】Most importantly, you should know what the teacher does is to make you better・ If you feel shy, you can write to the teacher・ You can also ask your parents to talk to the teacher about your problems・（具体建议）Wish you have a better life!（希望）YoursZhang Han。
广东省广州市白云区2019-2020学年九年级上学期期末化学试题(word无答案)
广东省广州市白云区2019-2020学年九年级上学期期末化学试题一、单选题(★) 1 . 垃圾分类人人有责。
下列属于厨余垃圾的是A．易拉罐B．旧报纸C．塑料瓶D．瓜果皮(★) 2 . 中国诗词、成语和谚语中有些蕴含着化学知识。
下列说法正确的是A．“好酒不怕巷子深”说明分子在不断地运动B．“只要功夫深，铁杵磨成针”描述的是化学变化C．“爆竹声中一岁除”描述的只有物理变化D．“釜底抽薪”体现的灭火原理是隔绝氧气（或空气）(★) 3 . 燃烧前常将汽油（含C 8H 18等）喷成雾状，可以A．减少O2消耗量B．增大汽油与空气的接触面C．降低汽油着火点D．使C8H18等分子变得更小(★★) 4 . 物质的性质决定其用途。
下列物质的用途与性质对应关系正确的是物质用途性质A干冰制造舞台烟雾效果二氧化碳不燃烧，也不支持燃烧B氮气食品防腐空气中含量最多C生石灰食品防潮剂能与水反应D一氧化碳冶炼金属单质具有可燃性A ．AB ．BC ．CD ．D(★) 5 . 下列操作正确的是A 溶解B 过滤C 加热液体D 用胶皮管塞塞住试管A ．AB ．BC ．CD ．D(★★) 6 . 提升“中国芯”的性能是我国信息产业的当务之急。
“中国芯”的核心材料是高纯度的单质硅，工业上制取粗硅的化学方程式为：SiO 2+2CSi+2CO↑，下列说法正确的是A ．单质硅结构和金刚石类似，由分子构成B ．该反应的基本类型为分解反应C ．在此反应中硅元素的化合价降低D ．硅元素在地壳中的含量最多(★★) 7 . 科学家日前研制出一种名叫“干水”的物质（如图），每个“干水”粒子是由小水滴、外层包上沙质硅膜组成的。
这种糖粉状物质的最大特点是具有强力吸收二氧化碳的能力，具有极高的商业价值。
下列有关“干水”的叙述正确的是A ．“干水”属于纯净物B ．“干水”的化学式为H 2OC ．“干水”可用于降低温室效应D ．“干水”吸收二氧化碳只发生物理变化(★) 8 . 下列有关实验现象的描述，正确的是A ．红磷在空气中燃烧，产生大量白烟B ．硫在氧气中燃烧，发出淡蓝色火焰C ．镁条在空气中燃烧，生成氧化镁D ．铁丝在氧气中燃烧，火星四射，生成红色固体(★) 9 . 空气是一种宝贵的自然资源。
2018-2019学年广东省广州市白云区九年级(上)期末数学试卷
16.（3分）某设计运动员在相同的条件下的射击成绩记录如下：
设计次数
20
40
100
200
400
1000
射中9环以上次数
15
33
78
4.【答案】B
【解析】解： ．掷一次骰子，向上一面的点数是 ，属于随机事件，
C、旋转中心为C，不符合题意；
D、旋转中心为O，不符合题意；
故选：A．
根据旋转的性质可得解．
本题考查了旋转的性质，熟练运用旋转的性质是本题的关键．
3.【答案】D
【解析】解：y=3x +2x的对称轴为：直线x=- =- ．
故选：D．
直接利用公式法得出二次函数的对称轴．
此题主要考查了二次函数的性质，正确记忆对称轴公式是解题关键．
参考答案及解析
一、选择题
1.【答案】B
【解析】解： ，
抛物线的开口向下，
故选： ．
根据当 时，抛物线 的开口向上，当 时，抛物线 的开口向下即可判定；
本题考查二次函数的性质，熟练掌握二次函数的性质是解决问题的关键，属于中考基础题．
2.【答案】A
【解析】解：A、旋转中心为点A，符合题意；
B、旋转中心为点B，不符合题意；
（1）求证：∠ B=∠ ACD，DE= BC；
（2）已知如图2，BG是△BDE的中线，延长ED至点F，使ED=FD，求证：BF=2BG．
25.（14分）如图，在平面直角坐标系xOy中，△ABC是等腰直角三角形，∠ BAC=90°，A（1，0），B（0，2），二次函数y= +bx-2的图象经过C点．
2019-2020广州白云区初三上学期期末化学【试卷+答案】
．溶解．过滤．加热液体．用胶皮管塞塞住试管A. B. C. D.提升“中国芯”的性能是我国信息产业的当务之急。
制取粗硅的化学方程式为：单质硅结构和金刚石类似，由分子构成在此反应中硅元素的化合价降低下列微观模拟图中的和分别表示氧原子和氢原子，则有关说法①②③①表示混合物③表示化合物燃煤会影响环境。
下列环境问题与燃煤没有直接关系的是（酸雨管收集的气体能使燃着的木条燃烧更旺实验一：验证空气的密度大于 B.实验二：验证空气中氧气含量实验三：验满 D.实验四：验证反应前后质量相等小题，共30分）如图为价类图表示元素的化合价与物质类别关系。
若它表示氮元素的部分关系图，点标示价的氮的氧化物，则：查资料可知：元素处于最高价，只有氧化性；元素处于最低价，只有还原性，则可能与水反应能生成和（硝酸），反应的化学方程式。
之间的联系，是化学学习的重要方法。
根据图示回答下列问题：微观角度我国研制的一种新型催化剂可将和转化为甲醇（）和。
若用“”表示氢原子，“”表示氧原子，“”表示碳原子，该反应的微观示意图（已经配平）如下：画出的微观示意图：（用黑色墨水笔作答）。
结构决定性质。
研究发现含有“过氧基”（）的物质具有很强的氧化性，可以作为①②③④通过分析组成和结构，我们可以预测物质的某些性质。
在你目前的知识储备范围内，关于的性质，你的推测是：小明对金属钠产生了好奇。
（用含有 ））毒重石要进行粉碎的目的是 ，气体 的化学式为 操作 的名称是 ，滤液 中可循环利用的物质除水外还有 。
三、实验题（本大题共4小题，共30分））根据下列实验装置改进，回答问题：实验室有如图所示装置，连接装置时，需根据导管的高度调节 处的高度，再确）下图中一段时间后，瓶内气体的黄绿色消失，原因。
（1）（2）（3）NH 3滴有酚酞 的水（4）（5）气体的实验室制取是学生必备的基本实验技能，请根据下列装置回答问题：ab写出图中标数字的仪器名称① ，② 。
实验室用加热高锰酸钾制取氧气的化学方程式为 ，若用 装置收集氧气，气体应从管口 （填“a”或“b”）进入。
2019-2020学年第一学期白云区九年级数学参考答案
解得： x1 1，x2 18（舍去） 答：广场中间小路宽为 1 米。
23.解：（1）如图即为所求
九年级数学
第 3 页（共 7 页）
（2）连接 OB, ABC为等边三角形
AB BC AC 6
AOB 120,BOD 180 AOB 60 AD为ABC的高
360
2
4 3 3 2
线段BD, AD,弧AB围成封闭图形面积为4 3 3 2
24.解： （1） 令y 0，则x2 (1 2a)x 2a 0 =(1-2a)2 41 (2a) =4a2 4a 1 8a 4a2 4a 1 (2a 1)2
1当k=0时，y 1，
如图①所示，直线与新图像有4个公共点。
2当k 0时，直线y kx 1必经过点(0,1)，
(a)当直线y kx 1过点(-1,0)时， -k 1 0, k 1.
如图②所示， 当k 1时，直线与新图像有3个公共点. 当0 k 1时，直线与新图像有4个公共点. 当k 1时，直线与新图像有2个公共点. (b)当直线y kx 1过点(4,0)时， 4k 1 0, k 1 .时，
随机抽取 2 位同学，可列树状图如下：
第1位
第2位
一共有 20 种可能出现的结果，抽到 A 学生的有 8 种可能的结果：
P(抽到A学生)
8= 20
2 5
九年级数学
第 2 页（共 7 页）
21.解：（1）如下图即为所求， A'(0,2),B'(3,0),C '(1,4).
（2）解：设二次函数解析式为 y ax2 bx c(a 0)
2018-2019学年白云区初三上期末考试2019.2.25
2018-2019学年白云区初三上期末考试一、语法选择（共15小题；每小题1分，满分15分）Do you like reading stories?Maybe you will answer,“No,I am not__1__child any more!”Yes,children all over the world always love stories.Chinese children are__2__in Monkey King’s story.It has been a popular bedtime story in China__3__many years.In fact,adults__4__love the story a lot.For then,Monkey King has become a very unforgettable part in the memory of__5__ childhood.The clever and humorous monkey__6__the hearts of many Chinese people.British boys and girls all know Alice’s Adventures in Wonderland__7__.As the name shows,it’s a story full of dangerous__8__exciting trips.Children laugh,cry and even get frightened with Alice together while__9__the story.Most American kids have read The Adventures of Tom Sawyer,by the famous writer,Mark Twain.Everyone likes the brave boy__10__also has lots of risks,some scenes of the story may make your heart__11__faster,for Tom and his friends meet some very bad men and__12__usually in danger.Of course in the end,they beat the bad ones.You__13__also ask me if I like stories.Yes,I have liked them since I was very young.At that time,I often__14__all my pocket money on storybooks.For me,stories are much__15__than chocolate!They help me learn a lot.So eight young or old,let’s enjoy stories.1. A.a B.an C.the D./2. A.interest B.interesting C.interested D.interestingly3. A.on B.for C.at D.of4. A.too B.also C.either D.as well5. A.they B.them C.their D.themselves6. A.wins B.will win C.win D.is winning7. A.good B.better C.best D.well8. A.nor B.so C.or D.but9. A.read B.reading C.to read D.to reading10. A.who B.which C.what D.when11. A.go B.goes C.going D.went12. A.is B.was C.are D.were13. A.need B.can C.should D.may14. A.spend B.spent C.will spend D.have spend15. A.delicious B.more delicious C.most delicious D.deliciously二、完形填空（共10小题；每小题1.5分，满分15分）A blind boy sat on the steps of a building with a hat beside his feet.He held a sign which said,“I am blind.Please __16__me.”There were only a few coins in the__17__.A man was walking by.He took a few coins from his pocket and dropped them into the hat.He then took the sign,turned it around,and__18__some words.He put the sign back so that everyone who walked by would see the new__19__.Soon the hat began to fill up.A lot more people were__20__money to the blind boy.That afternoon the man who hadchanged the sign came to see how things were.The boy recognized his footsteps and asked:"Were you the one who changed __21__sign this morning?What did you write?"The man said:"I only wrote the truth.I said what you said but in a different way."What he had written was:"Today is a beautiful day but I cannot see it."Do you think the first sign and the second sign were saying the same thing?Of course both signs told people the boy was__22__.But the first sign simply told people to help by putting some __23__in the hat.The second sign told people that they were able to enjoy the day,but the boy could not enjoy it because he was blind.The first sign simply said the boy was blind.The second sign reminded people they were lucky that they were not blind.There are__24__two lessons we can learn from this simple story.The first is:Be thankful for what you have.Someone else has less.Help where you can.The second is:Be creative.Think__25__.There is always a better way.16. A.call B.help C.choose D.praise17. A.bag B.wallet C.box D.hat18. A.wrote B.printed C.learnt D.cleaned19. A.ways B.stories C.words D.pictures20. A.accepting B.receiving C.borrowing D.giving21. A.her B.his C.my D.your22. A.kind B.deaf C.clever D.blind23. A.coats B.biscuits C.coins D.gifts24. A.at least B.at last C.at once D.at first25. A.surprisingly B.differently C.wonderfully D.warmly阅读（共两节，满分45）第一节阅读理解（共20小题；每小题2分，满分40分）AMy parents seldom encouraged me to ask for help,so I trained myself to become as independent as possible.I thought ifI asked for help,I would be a problem to other people.I walked into supermarket near my house,not buying anything.I just wanted to stay there quietly.The pain of losing myhusband was still too every time he’d pretend to go off and look for something special.He always bought me yellow roses.He loved roses.Now,standing by the meat,I searched for her the perfect small steak because my husband used to love steak.Suddenly a woman came up beside me.I watched as she picked up a large pack of T-bone steaks,dropped them in her basket,hesitated(犹豫不决),and then put them back.She saw me watching her and smiled,“My husband loves T-bone steaks,but they’re so expansive.”“My husband passed away eight days ago,”I told her.I found to control the sadness in my voice.“Buy him the T-bone steaks.And cherish every moment you have together.”1Surprised my words,she placed the T-bone steaks in her basket and walked away silently.However,several minutes later that woman came towards me again.In her arms she carried a package.On her face was the brightness smile I had ever seen.As she came closer,I saw what she held,and I couldn’t hold back my tears.“These are for you,”she said and placed three beautiful yellow roses in my hands.I wanted to tell her what the roses meant for me,but,still unable to speak.I watched as she walked away.I looked down at the beautiful roses.How did she know?Suddenly the answer seemed so clear.I wasn’t alone.There were still many people caring for me and willing to help me.26.The author went to the supermarket because__________.A.she wanted to buy some foodB.there were many sweet memories for herC.the roses there were much nicerD.her friend was waiting for her27.What did the woman give the author?A.Some yellow roses.B.Some beautiful pictures.C.A pack of T-bone steaks.D.A bowl of ice-cream.28.From the passage we can learn that the writer__________.A.learned a lesson from the tripB.got some good shoes in the endC.spent six hours visiting the city with the hostD.got through his fear of asking quite quickly29.The underlined word(in paragraph6)“opportunity”means__________.A.taskB.chanceC.excuseD.truth30.What can we learn from the passage?A.Being independent is always a good thing.B.Don’t go outside on rainy and windy days.C.Don’t be afraid to ask for help if you are in trouble.D.Wear good shoes during your trips.BCarl visited his grandparents on their farm.He was given a slingshot(弹弓)to play with in the woods.He was excited and practiced for some time.But he could never hit the target(靶子).Getting a little upset,he went back for dinner.As he was going back,he saw his grandma’s duck.Without thinking,he used the slingshot to hit the duck in the head and killed it.In a panic(惊慌),he hid the dead duck in the woodpile(柴堆),only to see his sister watching!But Sally said nothing.After lunch the next day,Grandma said,“Sally,help me with the dishes.”But Sally said,“Grandma,Johnny told me he wanted to help in the kitchen.”Then she whispered(耳语)to Johnny,“Remember the duck?”So Johnny did the dishes.Later that day,Grandpa asked if the children wanted to ride horses,and Grandma said,“I’m sorry but I need Sally to help me make supper.”Sally just smiled and said,“Well,that’s all right because Johnny told me he wanted to help you.”She whispered again,“Remember the duck?”So Sally went to ride horses and Johnny stayed behind to help make supper.After several days of doing both his chores and Sally’s,Johnny finally couldn’t stand it any more.He went to his grandma and said that he had killed the duck.Grandma smiled.“Sweetheart,I know,”said Grandma.“You see,I saw the whole thing at the window that day,but because I love you,I forgave you.I just waited to find out when you would tell me what you did.”31.What does the underlined word“it”in paragraph2refer to?A.The slingshot.B.The target.C.The duck.D.The head.32.Who actually saw Carl hit the duck?A.His parents.B.Only his sister.C.Only his grandma.D.His sister and grandma.33.What did Carl do after he hit the duck?A.He ate the duck.B.He hid the duck.C.He gave the duck to Sally.D.He gave the duck to his grandparents.34.Why did Carl keep helping Sally do chores?A.Because he had told her he would do harm.B.Because Sally didn’t know how to do them.C.Because he wanted Sally to keep the secret.D.Because Grandma asked him to do the chores.35.What has Carl learned from his experience?A.One should be brave.B.One should be Honest.C.One should be helpful.D.One should be patient.CAlix cried with joy during graduation at West Point(西点军校).His unusual journey is what makes his moment truly special.Alix had a reason to cry.In seven years,he went from speaking basic English in a poor community to graduating from one of the best military(军事的)and educational institutions(机构)in the United States.When he was very young,Alix was very interested in planes.And the dream of becoming a pilot changed him forever.“People where I’m from don’t grow up to be pilots.That’s not something you do,”said Alix.“You don’t just say I’m going to be a pilot and make it happen.”So how did he achieve his dream?What drove him into West Point?What drove him to the top of his class?It’s his father,Dieujuste,who has played the important role in his success.to care for his own family,Dieujuste dropped out of school at14,leaving his home to find work.Like any parents,the father wanted his children to have the opportunities (机会)that he didn’t have.Alix said,“My dad always said that education was the only gift he could give us,because he didn’t have anything material to give.”Driven by his father’s encouragement to used education and high marks as a ticket to a better life,Alix spent his teenage years as a hard-working student.“At this moment,three things came to my mind and led to those tears,”Alix explained.“The first is where I stared…The second is where I am…The third is my future.”36.What happened during Alix’s graduation?A.He couldn’t help crying.B.He spoke basic English.C.He didn’t get there on time.D.He set out on a new journey.37.Acceding to the fourth paragraph,people from Alix’s hometown might think his dream is__________.2A.interestingB.boringC.crazyD.small38.We can see Alix’s father__________.A.had an easy and rich lifeB.supported his son’s dreamC.received a good educationD.gave Alix many material gifts39.All of the follwing statements are true EXCEPT that__________.A.Alix is interested in planes.B.Alix used to be not good at English.C.Alix works hard to realize his dream.D.Alix once dropped out of school.40.What is the best title for this passage?A.Don’t Laugh at Others.B.Care for Your Family.C.Never Give up on Your Dream.D.Money is More Important than Education.DAccording to a new report,the cost of living has been rising around the world in recent years.In the study,researchers surveyed214cities worldwide.So,which cities are the most expensive to live?TokyoTokyo is one of the most expensive places to live.There are also two other Japanese cities that have made up the top10 list this year:Osaka and Nagoya.The cost of goods like a cup of coffee,fuel and a fast-food meal in Tokyo has gone up over the past year.Now,Tokyo is about one-third more expensive than Karachi,which is the least expensive city among the214cities.Monthly rent,luxury(奢华的)2-bedroom apartment:US$4,848Cup of coffee:US$8.29Daily international newspaper:US$6.38Fast-food meal:US$8.29SingaporeSingapore,like other cities in Asia,has seen a big inflow(流入)of foreigners,which has mainly pushed up the price of housing and other living costs.Known for its high rents compared to the rest of Southeast Asia,Singapore is also an expensive place to own a car.The permit(许可证)to buy a new car can cost between$46,000to over$67,000.however,its average monthly rent for a2-bedroom apartment is much lower than that in the above three Japanese cities.Monthly rent,luxury2-bedroom apartment:US$3,588Cup of coffee:US$5.18Daily international newspaper:US$3.59Fast-food meal:US$5.66Honh Kong,ChinaHong Kong,the only Chinese city to make the top10list,has been ranked the ninth most expensive place to live.The average monthly rent for2-bedroom apartment jumped by around US$1,300.With a limited housing supply,the average house prices iMonthly rent,luxury2-bedroom apartment:US$7,092Cup of coffee:US$6.83Daily international newspaper:US$3.61Fast-food meal:US$3.5441.In the survey,how many Japanese cities are in the top10list?A.One.B.Two.C.Three.D.Four.42.Which place is the cheapest to live in among the cities surveyen Hong Kong have risen sharply by over93percent inrecent years.A.Osaka.B.Hong Kong.C.Singapore.D.Karachi.43.In which place is the rent for a luxury2-bedroom apartment the cheapest?A.Hong Kong.B.Singapore.C.Tokyo.D.Osaka.44.Which of the following statements is NOT true?pared to Singapore,buying a car in Hong Kong is more expensive.B.Hong Kong had made the top10list in the survey.C.A daily international newspaper in Singapore is cheaper than that in Hong Kong.D.Too many foreigners moving in Singapore is the biggest factor in pushing up the cost of living there.45.Where does the passage moving in Singapore is the biggest factor in pushing up the cost of living there.A.A blind website.B.A fashion magazine.C.A survey report.D.A textbook.第二节阅读短文及文后选项选出可以填入空白处的最佳选项。
2019-2020学年广东省广州市白云区九年级(上)期末数学试卷
2019-2020学年广东省广州市白云区九年级（上）期末数学试卷一、选择题（本大题共10小題，每小題3分，满分30分.在每小题给出的四个选项中，只有一项是符合题目要求的，）1．（3分）方程240x -=的解是( ) A ．2x =B ．2x =-C ．2x =±D ．4x =±2．（3分）下列图形中，是中心对称图形的是( )A ．B ．C ．D ．3．（3分）二次函数2(1)2y x =-+的最小值是( ) A ．2-B ．2C ．1-D ．14．（3分）一枚质地均匀的骰子，它的六个面上分别有1到6的点数．下列事件中，是不可能事件的是( )A ．掷一次这枚骰子，向上一面的点数小于5B ．掷一次这枚骰子，向上一面的点数等于5C ．掷一次这枚骰子，向上一面的点数等于6D ．掷一次这枚骰子，向上一面的点数大于65．（3分）已知点C 为线段AB 延长线上的一点，以A 为圆心，AC 长为半径作A e ，则点B 与A e 的位置关系为( ) A ．点B 在A e 上B ．点B 在A e 外C ．点B 在A e 内D ．不能确定6．（3分）两个相邻自然数的积是132．则这两个数中，较大的数是( ) A ．11B ．12C ．13D ．147．（3分）下列抛物线中，其顶点在反比例函数12y x=的图象上的是( ) A ．2(4)3y x =-+B ．2(4)3y x =--C ．2(2)1y x =++D ．2(2)1y x =+-8．（3分）如图是一个可以自由转动的转盘，转盘分成黑、白两种颜色指针的位置固定，转动的转盘停止后，指针恰好指向白色扇形的穊率为78（指针指向OA 时，当作指向黑色扇形；指针指OB 时，当作指向白色扇形），则黑色扇形的圆心角(AOB ∠= )A ．40︒B ．45︒C ．50︒D ．60︒9．（3分）一根水平放置的圆柱形输水管横截面如图所示，其中有水部分水面宽8米，最深处水深2米，则此输水管道的半径是( )A ．8米B ．6米C ．5米D ．4米10．（3分）在下列函数图象上任取不同两点1(P x ，1)y ，2(Q x ，2)y ，一定能使2121()()0x x y y -->成立的是( )A ．21(0)y x x =-+<B ．228(0)y x x x =--+<C ．5(0)y x => D ．226(0)y x x x =+->二、填空题（本大题共6小题，每小题3分，满分18分.）11．（3分）在平面直角坐标系中，点(2,3)P -关于原点对称点P '的坐标是 ．12．（3分）从甲、乙、丙三人中任选两人参加“青年志愿者”活动，甲被选中的概率为 ． 13．（3分）已知圆锥的底面半径是3cm ，母线长是5cm ，则圆锥的侧面积为 2cm ．（结果保留)π14．（3分）如图，ABC ∆内接于O e ，35ACB ∠=︒，则OAB ∠= ．15．（3分）若关于x 的方程220(x x m m +-=是常数）有两个相等的实数根，则反比例函数my x=经过第 象限． 16．（3分）如图，在正方形ABCD 中，AB a =，点E ，F 在对角线BD 上，且ECF ABD ∠=∠，将BCE ∆绕点C 旋转一定角度后，得到DCG ∆，连接FG ．则下列结论：①FCG CDG ∠=∠；②CEF ∆的面积等于214a ；③FC 平分BFG ∠； ④222BE DF EF +=；其中正确的结论是 ．（填写所有正确结论的序号）三、解答题[本大飇共9小题，满分102分.解答应写岀文宁说明、证明过程或演算步骤.） 17．（9分）解方程：2680x x -+=．18．（9分）如图，在同一平面直角坐标系中，正比例函数2y x =的图象与反比例函数ky x=的图象交于A ，B 两点，过点A 作AC x ⊥轴，垂足为点C ，2AC =，求k 的值．19．（10分）如图，在ABC ∆中，边BC 与A e 相切于点D ，BAD CAD ∠=∠．求证：AB AC =．20．（10分）为了创建文明城市，增弘环保意识，某班随机抽取了8名学生（分别为A ，B ，C ，D ，E ，F ，G ，)H ，进行垃圾分类投放检测，检测结果如下表，其中“√”表示投放正确，“⨯”表示投放错误，学生A B C D E F G H垃圾类别可回收物√⨯⨯√√⨯√√其他垃圾⨯√√√√⨯√√餐厨垃圾√√√√√√√√有害垃圾⨯√⨯⨯⨯√⨯√（1）检测结果中，有几名学生正确投放了至少三类垃圾？请列举出这几名学生．（2）为进一步了解学生垃圾分类的投放情况，从检测结果是“有害垃圾”投放错误的学生中随机抽取2名进行访谈，求抽到学生A的概率．21．（12分）如图，在平面直角坐标系xOy中，(2,0)A-，(0,3)B，(4,1)C-．以原点O为'''，其中点A，B，C旋转后的对应点分别旋转中心，将ABC∆顺时针旋转90︒得到△A B C为点A'，B'，C'．'''，并写出点A'，B'，C'的坐标；（1）画出△A B C（2）求经过点B'，B，A三点的抛物线对应的函数解析式．22．（12分）为改善生态环境，建设美丽乡村，某村规划将一块长18米，宽10米的矩形场地建设成绿化广场，如图，内部修建三条宽相等的小路，其中一条路与广场的长平行，另两条路与广场的宽平行，其余区域种植绿化，使绿化区域的面积为广场总面积的80%．（1）求该广场绿化区域的面积；（2）求广场中间小路的宽．23．（12分）如图，在等边ABC ∆中，6AB =，AD 是高．（1）尺规作图：作ABC ∆的外接圆O e （保留作图痕迹，不写作法） （2）在（1）所作的图中，求线段AD ，BD 与¶AB 所围成的封闭图形的面积．24．（14分）已知抛物线2(12)2(y x a x a a =+--是常数）． （1）证明：该抛物线与x 轴总有交点；（2）设该抛物线与x 轴的一个交点为(,0)A m ，若25m <…，求a 的取值范围；（3）在（2）的条件下，若a 为整数，将抛物线在x 轴下方的部分沿x 轴向上翻折，其余部分保持不变，得到一个新图象G ，请你结合新图象，探究直线1(y kx k =+为常数）与新图象G 公共点个数的情况．25．（14分）如图，AB 是O e 的直径，点C 是O e 上一点（点C 不与A ，B 重合），连接CA ，CB ．ACB ∠的平分线CD 与O e 交于点D ．（1）求ACD ∠的度数；（2）探究CA ，CB ，CD 三者之间的等量关系，并证明；（3）E 为O e 外一点，满足ED BD =，5AB =，3AE =，若点P 为AE 中点，求PO 的长．2019-2020学年广东省广州市白云区九年级（上）期末数学试卷参考答案与试题解析一、选择题（本大题共10小題，每小題3分，满分30分.在每小题给出的四个选项中，只有一项是符合题目要求的，）1．（3分）方程240x -=的解是( ) A ．2x =B ．2x =-C ．2x =±D ．4x =±【解答】解：24x =，2x ∴=±．故选：C ．2．（3分）下列图形中，是中心对称图形的是( )A ．B ．C ．D ．【解答】解：A 、不是中心对称图形，故此选项错误；B 、不是中心对称图形，故此选项错误；C 、不是中心对称图形，故此选项错误；D 、是中心对称图形，故此选项正确；故选：D ．3．（3分）二次函数2(1)2y x =-+的最小值是( ) A ．2-B ．2C ．1-D ．1【解答】解：根据二次函数的性质，当1x =时，二次函数2(1)2y x =-+的最小值是2． 故选：B ．4．（3分）一枚质地均匀的骰子，它的六个面上分别有1到6的点数．下列事件中，是不可能事件的是( )A ．掷一次这枚骰子，向上一面的点数小于5B ．掷一次这枚骰子，向上一面的点数等于5C ．掷一次这枚骰子，向上一面的点数等于6D ．掷一次这枚骰子，向上一面的点数大于6【解答】解：A ．掷一次这枚骰子，向上一面的点数小于5，属于随机事件，不合题意；B ．掷一次这枚骰子，向上一面的点数等于5，属于随机事件，不合题意；C ．掷一次这枚骰子，向上一面的点数等于6，属于随机事件，不合题意；D ．掷一次这枚骰子，向上一面的点数大于6，属于不可能事件，符合题意；故选：D ．5．（3分）已知点C 为线段AB 延长线上的一点，以A 为圆心，AC 长为半径作A e ，则点B 与A e 的位置关系为( ) A ．点B 在A e 上B ．点B 在A e 外C ．点B 在A e 内D ．不能确定【解答】解：Q 点C 为线段AB 延长线上的一点，AC AB ∴>，∴以A 为圆心，AC 长为半径作A e ，则点B 与A e 的位置关系为点B 在A e 内，故选：C ．6．（3分）两个相邻自然数的积是132．则这两个数中，较大的数是( ) A ．11B ．12C ．13D ．14【解答】解：设这两个数中较大的数为x ，则较小的数为(1)x -， 依题意，得：(1)132x x -=，解得：112x =，211x =-（不合题意，舍去）． 故选：B ．7．（3分）下列抛物线中，其顶点在反比例函数12y x=的图象上的是( ) A ．2(4)3y x =-+ B ．2(4)3y x =-- C ．2(2)1y x =++D ．2(2)1y x =+-【解答】解：12y x=Q ， 12k xy ∴==，A 、2(4)3y x =-+的顶点为(4,3)，4312⨯=，故2(4)3y x =-+的顶点在反比例函数12y x=的图象上，B 、2(4)3y x =--的顶点为(4,3)-，4(3)1212⨯-=-≠，故2(4)3y x =--的顶点不在反比例函数12y x=的图象上， C 、2(2)1y x =++的顶点为(2,1)-，21212-⨯=-≠，故2(2)1y x =++的顶点不在反比例函数12y x=的图象上， D 、2(2)1y x =+-的顶点为(2,1)--，2(1)212-⨯-=≠，故2(2)1y x =+-的顶点不在反比例函数12y x=的图象上， 故选：A ．8．（3分）如图是一个可以自由转动的转盘，转盘分成黑、白两种颜色指针的位置固定，转动的转盘停止后，指针恰好指向白色扇形的穊率为78（指针指向OA 时，当作指向黑色扇形；指针指OB 时，当作指向白色扇形），则黑色扇形的圆心角(AOB ∠= )A ．40︒B ．45︒C ．50︒D ．60︒【解答】解：Q 指针恰好指向白色扇形的穊率为78， ∴黑、白两种颜色的扇形的面积比为1:7，1360458AOB ∴∠=⨯︒=︒，故选：B ．9．（3分）一根水平放置的圆柱形输水管横截面如图所示，其中有水部分水面宽8米，最深处水深2米，则此输水管道的半径是( )A ．8米B ．6米C ．5米D ．4米【解答】解：连接OA ，作OC AB ⊥交AB 于C ，交圆于D ， 由题意得，8AB =，2CD =，OC AB ⊥Q ，142AC AB ∴==， 设圆的半径为r ，则2OC r =-，由勾股定理得，222OA OC AC =+，即222(2)4r r =-+，解得，5r =，即此输水管道的半径是5米， 故选：C ．10．（3分）在下列函数图象上任取不同两点1(P x ，1)y ，2(Q x ，2)y ，一定能使2121()()0x x y y -->成立的是( )A ．21(0)y x x =-+<B ．228(0)y x x x =--+<C ．50)y x > D ．226(0)y x x x =+->【解答】解：A 、20k =-<Qy ∴随x 的增大而减小，即当12x x >时，必有12y y <∴当0x <时，2121()()0x x y y --<，故A 选项不符合；B 、10a =-<Q ，对称轴为直线1x =-，∴当10x -<<时，y 随x 的增大而减小，当1x <-时y 随x 的增大而增大， ∴当1x <-时：能使2121()()0x x y y -->成立，故B 选项不符合；C 、Q 50>，∴当0x >时，y 随x 的增大而减小， ∴当0x >时，2121()()0x x y y --<，故C 选项不符合；D 、20a =>Q ，对称轴为直线14x =-，∴当14x >-时y 随x 的增大而增大，∴当0x >时，2121()()0x x y y -->，故D 选项符合；故选：D ．二、填空题（本大题共6小题，每小题3分，满分18分.）11．（3分）在平面直角坐标系中，点(2,3)P -关于原点对称点P '的坐标是 (2,3)- ． 【解答】解：根据中心对称的性质，得点(2,3)P -关于原点的对称点P '的坐标是(2,3)-． 故答案为：(2,3)-．12．（3分）从甲、乙、丙三人中任选两人参加“青年志愿者”活动，甲被选中的概率为 23． 【解答】解：树状图如图所示：共有6个等可能的结果，甲被选中的结果有4个，∴甲被选中的概率为4263=； 故答案为：23．13．（3分）已知圆锥的底面半径是3cm ，母线长是5cm ，则圆锥的侧面积为 15π 2cm ．（结果保留)π【解答】解：底面圆的半径为3cm ，则底面周长6cm π=，侧面面积216515()2cm ππ=⨯⨯=．14．（3分）如图，ABC ∆内接于O e ，35ACB ∠=︒，则OAB ∠= 55︒ ．【解答】解：ACB ∠Q 与AOB ∠都对¶AB ，270AOB ACB ∴∠=∠=︒， OA OB =Q ，18070552OAB OBA ︒-︒∴∠=∠==︒． 故答案为：55︒15．（3分）若关于x 的方程220(x x m m +-=是常数）有两个相等的实数根，则反比例函数my x=经过第 二，四 象限． 【解答】解：Q 方程220(x x m m +-=是常数）有两个相等的实数根，∴△2241()440m m =-⨯⨯-=+=，1m ∴=-；∴反比例函数my x=经过第二，四象限， 故答案为二，四．16．（3分）如图，在正方形ABCD 中，AB a =，点E ，F 在对角线BD 上，且ECF ABD ∠=∠，将BCE ∆绕点C 旋转一定角度后，得到DCG ∆，连接FG ．则下列结论： ①FCG CDG ∠=∠；②CEF ∆的面积等于214a ；③FC 平分BFG ∠； ④222BE DF EF +=；其中正确的结论是 ①③④ ．（填写所有正确结论的序号）【解答】解：Q 四边形ABCD 是正方形，AB BC CD AD a ∴====，45ABD CBD ADB BDC ∠=∠=∠=∠=︒， 45ECF ABD ∴∠=∠=︒， 45BCE FCD ∴∠+∠=︒，Q 将BCE ∆绕点C 旋转一定角度后，得到DCG ∆，45CBE CDG ∴∠=∠=︒，BE DG =，CE CG =，DCG BCE ∠=∠， 45FCG ECF ∴∠=∠=︒，45FCG CDG ∴∠=∠=︒，故①正确， EC CG =Q ，FCG ECF ∠=∠，FC FC =，()ECF GCF SAS ∴∆≅∆EF FG ∴=，EFC GFC ∠=∠，ECF CFG S S ∆∆=， CF ∴平分BFG ∠，故③正确，90BDG BDC CDG ∠=∠+∠=︒Q ，222DG DF FG ∴+=，222BE DF EF ∴+=，故④正确， DF DG FG +>Q ，BE DF EF ∴+>，CEF BEC DFC S S S ∆∆∆∴<+，CEF ∴∆的面积21124BCD S a ∆<=，故②错误；故答案为：①③④三、解答题[本大飇共9小题，满分102分.解答应写岀文宁说明、证明过程或演算步骤.） 17．（9分）解方程：2680x x -+=． 【解答】解：(2)(4)0x x --=，20x -=或40x -=，所以12x =，24x =．18．（9分）如图，在同一平面直角坐标系中，正比例函数2y x =的图象与反比例函数ky x=的图象交于A ，B 两点，过点A 作AC x ⊥轴，垂足为点C ，2AC =，求k 的值．【解答】解：AC x ⊥Q 轴，2AC =，A ∴的纵坐标为2，Q 正比例函数2y x =的图象经过点A ，22x ∴=，解得1x =，(1,2)A ∴，Q反比例函数kyx=的图象经过点A，122k∴=⨯=．19．（10分）如图，在ABC∆中，边BC与Ae相切于点D，BAD CAD∠=∠．求证：AB AC=．【解答】解：BCQ与Ae相切于点D，AD BC∴⊥，90ADB ADC∴∠=∠=︒，BAD CAD∠=∠Q，AD AD=，()ABD ACD ASA∴∆≅∆，AB AC∴=．20．（10分）为了创建文明城市，增弘环保意识，某班随机抽取了8名学生（分别为A，B，C，D，E，F，G，)H，进行垃圾分类投放检测，检测结果如下表，其中“√”表示投放正确，“⨯”表示投放错误，学生垃圾类别A B C D E F G H可回收物√⨯⨯√√⨯√√其他垃圾⨯√√√√⨯√√餐厨垃圾√√√√√√√√有害垃圾⨯√⨯⨯⨯√⨯√（1）检测结果中，有几名学生正确投放了至少三类垃圾？请列举出这几名学生．（2）为进一步了解学生垃圾分类的投放情况，从检测结果是“有害垃圾”投放错误的学生中随机抽取2名进行访谈，求抽到学生A的概率．【解答】解：（1）有5位同学正确投放了至少三类垃圾，他们分别是B、D、E、G、H 同学，（2）“有害垃圾”投放错误的学生有A、C、D、E、G同学，从中抽出2人所有可能出现的结果如下：共有20种可能出现的结果数，其中抽到A 的有8种， 因此，抽到学生A 的概率为82205=． 21．（12分）如图，在平面直角坐标系xOy 中，(2,0)A -，(0,3)B ，(4,1)C -．以原点O 为旋转中心，将ABC ∆顺时针旋转90︒得到△A B C '''，其中点A ，B ，C 旋转后的对应点分别为点A '，B '，C '．（1）画出△A B C '''，并写出点A '，B '，C '的坐标； （2）求经过点B '，B ，A 三点的抛物线对应的函数解析式．【解答】解：（1）如图△A B C '''即为所求．(0,2)A '，(3,0)B '，(1,4)C '（2）设抛物线的解析式为(2)(3)y a x x =+-，把(0,3)B 代入得到12a =-，∴抛物线的解析式为211322y x x =-++． 22．（12分）为改善生态环境，建设美丽乡村，某村规划将一块长18米，宽10米的矩形场地建设成绿化广场，如图，内部修建三条宽相等的小路，其中一条路与广场的长平行，另两条路与广场的宽平行，其余区域种植绿化，使绿化区域的面积为广场总面积的80%． （1）求该广场绿化区域的面积； （2）求广场中间小路的宽．【解答】解：（1）181080%144⨯⨯=（平方米）． 答：该广场绿化区域的面积为144平方米． （2）设广场中间小路的宽为x 米， 依题意，得：(182)(10)144x x --=， 整理，得：219180x x -+=，解得：11x =，218x =（不合题意，舍去）． 答：广场中间小路的宽为1米．23．（12分）如图，在等边ABC ∆中，6AB =，AD 是高．（1）尺规作图：作ABC ∆的外接圆O e （保留作图痕迹，不写作法） （2）在（1）所作的图中，求线段AD ，BD 与¶AB 所围成的封闭图形的面积．【解答】解：（1）如图，O e 即为所求．（2）ABC ∆Q 是等边三角形，AD BC ⊥，BH AC ⊥，3BD CD ∴==，1302OBD ABC ∠=∠=︒，2120AOB C ∠=∠=︒，tan303OD BD ∴=︒=g 223OB OD ==∴线段AD ，BD 与¶AB所围成的封闭图形的面积2120(23)3313342BODOAB S S ππ∆⋅⋅=+⨯=+扇形 24．（14分）已知抛物线2(12)2(y x a x a a =+--是常数）． （1）证明：该抛物线与x 轴总有交点；（2）设该抛物线与x 轴的一个交点为(,0)A m ，若25m <…，求a 的取值范围；（3）在（2）的条件下，若a 为整数，将抛物线在x 轴下方的部分沿x 轴向上翻折，其余部分保持不变，得到一个新图象G ，请你结合新图象，探究直线1(y kx k =+为常数）与新图象G 公共点个数的情况．【解答】解：（1）设0y =，则20(12)2x a x a =+--，Q △2(12)41(2)(12)20a a a =--⨯⨯-=+…， 2(12)20x a x a ∴+--=有实数根，∴该抛物线与x 轴总有交点；（2）Q 抛物线与x 轴的一个交点为(,0)A m ，20(12)2m a m a ∴=+--，1m ∴=-，2m a =，25m <Q …， 225a ∴<…，512a ∴<…； （3）512a <Q …，且a 为整数， 2a ∴=，∴抛物线解析式为：234y x x =--，如图，当0k >时，若1y kx =+过点(1,0)-时，直线1(y kx k =+为常数）与新图象G 公共点有3个， 即1k =，当01k <<时，直线1(y kx k =+为常数）与新图象G 公共点有4个， 当1k >时，直线1(y kx k =+为常数）与新图象G 公共点有2个， 如图，当0k <时，若1y kx =+过点(4,0)时，直线1(y kx k =+为常数）与新图象G 公共点有3个，即14k =-，当104k -<<时，直线1(y kx k =+为常数）与新图象G 公共点有4个，当14k <-时，直线1(y kx k =+为常数）与新图象G 公共点有2个，25．（14分）如图，AB 是O e 的直径，点C 是O e 上一点（点C 不与A ，B 重合），连接CA ，CB ．ACB ∠的平分线CD 与O e 交于点D ．（1）求ACD ∠的度数；（2）探究CA ，CB ，CD 三者之间的等量关系，并证明；（3）E 为O e 外一点，满足ED BD =，5AB =，3AE =，若点P 为AE 中点，求PO 的长．【解答】解：（1）AB Q 是直径，点C 在圆上，90ACB ∴∠=︒，ACB ∠Q 的平分线CD 与O e 交于点D ， 45ACD ∴∠=︒；（2）2BC AC CD +=，连接CO 延长与圆O 交于点G ，连接DG 、BG ，延长DG 、CB 交于点F ；90CDG CBG ∴∠=∠=︒， 90ACB ∠=︒Q ， //AC BG ∴， CGB ACG ∴∠=∠， 45CGB DCG ∴∠=︒+∠， 90CGD CGD ∠=︒-∠Q ，180(45)(90)45BGF CGD CGD ∴∠=︒-︒+∠-︒-∠=︒，BGF ∴∆是等腰直角三角形， BG BF ∴=，()ACO BGO SAS ∆≅∆Q ，AG BF ∴=，CDF ∆Q 是等腰三角三角形，2CF CD ∴=， 2BC AC CD ∴+=；（3）过点A 作AM ED ⊥，过点B 作BN ED ⊥交ED 延长线与点N ，连接BE ；45ACD ABD ∠=∠=︒Q ，90ADB ∠=︒，AD BD ∴=， 5AB =Q ，52BD AD ∴==， MAD BDN ∠=∠Q ，Rt AMD Rt DNB(AAS)∴∆≅∆，AM DN ∴=，MD BN =，ED BD =Q ，AED ∴∆是等腰三角形， 3AE =Q ，382AM ∴=，825DM =， 52382EN ∴=+，82BN =， 在Rt EBN ∆中，25341BE =+，P Q 是AE 的中点，O 是AB 的中点，12OP BE ∴=， 25341OP +∴=．。
广州市白云区九年级上学期语文期末考试试卷
广州市白云区九年级上学期语文期末考试试卷姓名:________ 班级:________ 成绩:________一、句子默写 (共1题；共10分)1. （10分）(2019·广东模拟) 根据课文默写古诗文。
（1）一曲新词酒一杯，去年天气旧亭台。
________？（晏殊《浣溪沙》）（2）夫战，勇气也。
________，再而衰，三而竭。
（《曹刿论战》）（3）行路难！行路难！多歧路，今安在？________，________。
（李白《行路难》）（4）王安石的《登飞来峰》中“________，________”两句诗，借景抒情，化实为虚，表现了诗人高膳远瞩的博大胸怀和不怕困难的豪迈气概。
（5）请将韩愈的《左迁至蓝关示侄孙湘》默写完整。
________，________。
________，________！去横秦岭家何在？雪拥蓝关马不前。
知汝远来应有意，好收吾骨瘴江边。
二、综合性学习 (共2题；共14分)2. （7分） (2018七上·阜阳月考) 阅读下面一段文字，按照要求完成以下各题。
轻轻地打开部编人教版七年级上册语文课本，眼前花团锦簇，美不胜收；解决散步时的分歧彰显中华民族尊老爱幼的美德；tān痪的史铁生在秋天怀念与母亲决别时收获着“好好儿活”的勇气；跟轻风流水应和着的牧童的笛声传递着春的气息；还有那可爱的水藻把终年贮蓄的绿色奉献给济南的冬天……站在新的历史起点，在语文的世界里徜徉，我们不忘初心，砥砺前行！（1）给划线字注音，根据拼音写汉字。
分歧（________）贮蓄（________）tān（________）痪（2）文中有一个错别词是________，应改为________（3）文中“徜徉”的意思是________。
（4）文中的修辞有________。
3. （7分）(2016·南平) 阅读下面一段文字，完成小题。
风景是水光山色，也是一种精神。
三峡的神女峰，黄山的天都峰□庐山的小和尚拜月……每一处景点无论其大小都有个传说。
广东省广州市白云区2019-2020学年九年级(上)期末考试物理试题
2019-2020学年白云区第一学期期末教学质量检测九年级物理（试题）笫一部分选择题（共36分）一、单项选择题（选出最优的一个选项，每小题3分，共36分）1.古语道：“人要实，火要虚”。
此话的意思是说做人要脚踏实地，才能事业有成；可燃物要架空些，才能燃烧更旺。
“火要虚”的目的是（）A. 增大可燃物与空气的接触面B. 提高可燃物的着火点C. 增大可燃物的热值D. 增加空气中氧气的含量2.水具有比热容大的特点，从而被广泛应用。
下列现象的原因及其应用实例与水的比热容大小无关的是（）A. 海边的昼夜温差较小B. 冬天暖气设备用水供暖C. 夏天在室内地面上洒水降温D. 用水冷却汽车发动机3.如图所示，对于图片中描述的的物理过程，下列分析中正确的是（）A. 图甲，厚玻璃内空气被压缩时，空气的内能减少B. 图乙，瓶子内的空气推动塞子跳起时，空气的内能增大C. 图丙，试管内的水蒸气推动了塞子冲出时，水蒸气的内能减少D. 图丁，汽缸内的气体推动活塞向下运动时，气体的内能增大4.2017年底，“悟空”号卫星上的计算机被太空中带正电的某些粒子击中，导致”死机”，在遥控指令下，计算机重新启动，卫星恢复正常.带正电的粒子可能是A. 原子核质子B. 原子核中子C. 电子原子核D. 电子质子5.青少年科技创新材料中有一种变光二极管，电流从其P端流入时发红光，从其Q端流入时发绿光，奥秘在于其内部封装有一红一绿两个发光二极管，发光二极管具有单向导电性，其符号为，当电流从“+”极流入时二极管能通电且发光，当电流从“﹣”极流入时二极管不能发光，则该变光二极管的内部结构可能是下图中的（）A. B.C. D.6.如图所示的四个电路中，电压U都相等，并且电阻R1大于R2，电流表示数最大的是（）A. B. C.D.7.如图是探究电流通过导体时产生热的多少跟什么因素有关的实验装置，两个透明容器中密封着等量的空气。
开关闭合后，则（）A. 左侧容器中导体产生的热量较多B. 图中两导体串联，能探究电热与电流关系C. 若图中两导体改为并联，右侧导体产生的热量较多D. 一段时间后，右侧U 形管两端液柱高度差较左侧大 8.如图所示为小刚所连两盏白炽灯和两个插座的电路图。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
广东省广州市白云区2019届九年级上学期期末考试
数学试题
一、选择题(每小題3分，共30分)
1.抛物线y＝﹣x2开口方向是()
A. 向上
B. 向下
C. 向左
D. 向右
2.下列旋转中，旋转中心为点A的是()
A. B.
C. D.
3.二次函数y＝3x2+2x的图象的对称轴为()
A. x＝﹣2
B. x＝﹣3
C. x=
D. x=
4.下列事件中，是必然事件的是()
A. 掷一次骰子，向上一面的点数是6
B. 任意画个三角形，其内角和为180°
C. 篮球队员在罚球线上投篮一次，未投中
D. 一元二次方程一定有两个实数根
5.一元二次方程ax2+bx+c＝0，若有两根1和﹣1，那么a+b+c＝()
A. ﹣1
B. 0
C. 1
D. 2
6.在抛物线y＝x2﹣4x﹣4上的一个点是()
A. (4，4)
B. (3，﹣1)
C. (﹣2，﹣8)
D. (，
)
7.把抛物线y＝x2()得到抛物线y＝(x+1)2﹣1．
A. 向左平移1个单位长度，再向上平移1个单位长度
B. 向左平移1个单位长度，再向下平移1个单位长度
C. 向石平移1个单位长度，再向上平移1个单位长度
D. 向右平移1个单位长度，再向下平移1个单位长度
8.AB、CD为⊙O的两条不重合的直径，则四边形ACBD一定是()
A. 等腰梯形
B. 矩形
C. 菱形
D. 正方形
9.用配方法解下列方程时，配方有错误的是()
A. x2+8x+9＝0化为(x+4)2＝25
B. x2﹣2x﹣99＝0化为(x﹣1)2＝100
C. 2t2﹣7t﹣4＝0化为(t)2=
D. 3x2﹣4x﹣2＝0化为(x)2=
10.在同一平面直角坐标系中，函数y＝kx与y＝的图象大致是()
A. (1)(3)
B. (1)(4)
C. (2)(3)
D. (2)(4)
二、填空题(本大题共6小题，每小题3分，共18分)
11.反比例函数y＝的图象在第_____象限．
12.⊙O的半径为10cm，点P到圆心O的距离为12cm，则点P和⊙O的位置关系是_____．
13.当m满足条件_____时，关于x的方程(m2﹣4)x2+mx+3＝0是一元二次方程．
14.已知函数y＝2(x﹣3)2+1，当_____(填写x需满足的条件)时，y随x的增大而增大．
15.不透明袋子中装有红、绿小球各一个，除颜色外无其他差别，随机摸出一个小球后，放回并摇匀，再随机摸出一个，则第一次摸到红球，第二次摸到绿球的概率为_____．
16.某设计运动员在相同的条件下的射击成绩记录如下：
根据频率的稳定性，估计这名运动员射击一次“射中9环以上”的概率是_____．
三、解答题(本大题共9小题，共102分)
17.解下列方程：x2+x(3x﹣4)＝0
18.画出△AOB关于点O对称的图形．
19.请你分析以下问题：
某校亲子运动会中，小美一家三口参加“三人四足”比赛，需要小美、爸爸和妈妈排成一横排，求小美排在妈妈右侧身旁的概率．
20.（9分）（2015•泉州）如图，在平面直角坐标系中，点A（，1）、B（2，0）、O（0，
0），反比例函数y=图象经过点A．
（1）求k的值；
（2）将△AOB绕点O逆时针旋转60°，得到△COD，其中点A与点C对应，试判断点D是否在该反比例函数的图象上？
21.⊙O的直径为10cm，AB、CD是⊙O的两条弦，AB∥CD，AB＝6cm，CD＝8cm，求AB 和CD之间的距离．
22.关于x的一元二次方程x2﹣(k+3)x+2k+2＝0．
(1)求证：方程总有两个实数根；
(2)若方程有一个根小于1，求k的取值范围．
23.如图，有一块矩形铁皮(厚度不计)，长10分米，宽8分米，在它的四角各切去一个同样的正方形，然后将四周突出部分折起，就能制作一个无盖方盒．
(1)若无盖方盒的底面积为48平方分米，那么铁皮各角应切去边长是多少分米的正方形？
(2)若要求制作的无盖方盒的底面长不大于底面宽的3倍，并将无盖方盒内部进行防锈处理，侧面每平方分米的防锈处理费用为0.5元，底面每平方分米的防锈处理费用为2元，问铁皮各角切去边长是多少分米的正方形时，总费用最低？最低费用为多少元？
24.已知如图1，在△ABC中，∠ACB＝90°，以AC为直径的⊙O交AB于D，过点D作⊙O的切线交BC于点E．
(1)求证：∠B＝∠ACD，DE＝BC；
(2)已知如图2，BG是△BDE的中线，延长ED至点F，使ED＝FD，求证：BF＝2BG．
25.如图，在平面直角坐标系xOy中，△ABC是等腰直角三角形，∠BAC＝90°，A(1，0)，B(0，2)，二次函数y＝x2+bx﹣2的图象经过C点．
(1)求二次函数的解析式；
(2)平移该二次函数图象的对称轴所在直线l，若直线l恰好将△ABC的面积分为1：2两部分，请求出此时直线l与x轴的交点坐标；
(3)将△ABC以AC所在直线为对称轴翻折180°，得到△AB′C，那么在二次函数图象上是否存在点P，使△PB′C是以B′C为直角边的直角三角形？若存在，请求出P点坐标；若不存在，请说明理由．。