成都七中实验学校(初中部)2020年期中单元测试

四川省成都七中实验学校2020学年八年级英语下学期期中试题（无答案）人教新目标版第一部分听力测试（共25小题，计25分）一、听句子，根据所听到的内容选择正确答语。

每题读两遍。

(共6小题，每小题l分；计6分)( ) 1. A. Yes, please. B. Thanks. C. You are amazing.( ) 2. A. I’d love to go. B. No problem. C. Either is OK.( ) 3. A. Have a good time. B. Be careful! C. See you!( ) 4. A. Let’s go home. B. I have no idea. C. You’d better take a raincoat.( ) 5. A. You are welcome. B. Nothing serious. C. No, thanks.( ) 6. A. It’s 5 d ollars. B. Yes, I am. C. No, I didn’t.二、听句子，选择与所听到的句子内容相符的图片，并将代表图片的字母填在相应的题号后。

每题读两遍。

(共4小题，每小题 1分；计4分)7. 8. 9. 10.三、听对话，根据对话内容及问题选择选择正确答案。

每题读两遍。

(共10小题，每小题l分；计10分)( ) 11. A. She has a fever. B. She is ill in hospital. C. She is too tired.( ) 12. A. English. B. Physics. C. Math.( ) 13. A. Hamburgers. B. Dumplings. C. Noodles.( ) 14. A. For two week s. B. For three weeks. C. For four weeks.( ) 15. A. At a hotel. B. At a cinema. C. At an airport.( ) 16. A. 55. B. 45. C. 35.( ) 17. A. A dictionary. B. An MP4. C. A camera.( ) 18. A. His uncle. B. His grandfather. C. His cousin. ( ) 19. A. It is broken. B. It is lost. C. It runs out of ink.( ) 20. A. 1.5 meters. B. 1.4 meters. C. 1.35 meters.四、听短文，根据短文内容选择正确答案。

2020年成都七中初中学校高三英语上学期期中考试试卷及答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AOn a rainy afternoon, maybe one of the following books will keep you company leisurely, allowing you to spend your time alone as well as stepping into a different world.Don’t Shed Your Tears for Anyone Who Lives on These Streets,by Patricio PronIn April 1945,Italy, a writer disappeared at a conference and was found dead at another place. Thirty years later, a young man interviewed survivors from the conference, trying to uncover the truth about what happened and its consequences. This novel, by a well-known Argentine writer, explores art, crime and politics.When Breath Becomes Air, by Paul KalanithiAt thirty-six, Paul Kalanithi was diagnosed (诊断) with stage IV lung cancer. One day he was a doctor treating the dying, and the next he was a patient. This autobiography finds hope and beauty in the face of death as Kalanithi attempts to answer the question “What makes a life worth living?”.To Killa Mockingbird, by Harper LeeSet in a smallAlabamatown in the 1930s, the story focuses on honest, highly respected lawyer Atticus Finch who puts his career on the line when he agrees to represent Tom Robinson, a black man accused of committing a crime.Nobody Will Tell You This But Me: A true (as told to me) storyby Bess KalbBess Kalb saved every voicemail from her grandmother Bobby Bell who died at ninety. In this book, Bobby is speaking to Bess once more, in a voice as loving as it ever was in life and brings us several generations of brave women. They include Bobby’s mother, who traveled alone fromBelarustoAmericato survive, and Bess’s mother, who always fought against convention.1.What type of book is the first novel?A.Sci-fi.B.Biography.C.Detective books.D.History books.2.Which book explores life and death?A.To Kill a MockingbirdB.When Breath Becomes AirC.Don’t Shed Your Tears for Anyone Who Lives on These StreetsD.Nobody Will Tell You This But Me: A true (as told to me) story3.Who is the main character in the last novel?A.Bobby Bell.B.Bess Kalb.C.Bess’s mother.D.Bobby’s mother.BBill Gates on how to fight future pandemicsWHEN HISTORIANS write the book on the covid-19 pandemic, what we've lived through so far will probably take up only the first third or so.The bulk of the story will be what happens next.I believe that humanity will beat this pandemic, but only when most of the population is vaccinated(接种疫苗）.Until then, life will not return to normal.As the pandemic slows in developed nations,itwill accelerate in developing ones.Their experience,however,will be worse.In poorer countries,where fewer jobs can be done remotely,distancing measures won't work as well.The virus will spread quickly,and health systems won't be able to care for the infected.Wealthy nations can help.But people in rich and poor places alike will be safe only once we have an effective medical solution for this virus,which means a vaccine.My hope is that,by the second half of 2021,facilities around the world will be manufacturing a vaccine.If that's the case,it will be a history-making achievement: the fastest humankind has ever gone from recognizing a new disease to immunizing（免疫）against it.Apart from this progress in vaccines,two other big medical breakthroughs will emerge from the pandemic.One will be in the field of diagnostics.The next time a novel virus crops up,people will probably be able to test for it at home.Researchers could have such a test ready within a few months of identifying a new disease.The third breakthrough will be in antiviral drugs.We haven't been as effective at developing drugs to fight viruses as we have those to fight bacteria.But that will Researchers will develop large diverse libraries of antivirals,which they'll be able to scan trough and quickly find effective treatments for novel viruses.All three technologies will prepare us for the next pandemic by allowing us to intervene(干预）early when the number of cases is still very low.Our progress won't be in science alone.It will also be in our ability to make sure everyone benefits from that science.In the years after 2021,I think we'll learn from the years after 1945. With the end of the Second World War, leaders built international institutions like the UN to prevent more conflicts.After covid-19, leaders will prepareinstitutions to prevent the next pandemic.These will be a mix of national,regional and global organizations.I expect they will participate in regular"germ games”in the same way as armed forces take part in War games.These will keep us ready for the next time a novel virus jumps from bats or birds to humans.I hope wealthy nations include poorer ones in these preparations,especially by devoting more foreign aid to building up their primary health-care systems.This pandemic has shown us that viruses don't obey border laws and that we are all connected biologically by a network of microscopic germs,whether we like it or not.The best analogy(类比）for today might be November 10th 1942.Britainhad just won its first land victory of the war,and Winston Churchill declared in a speech: “This is not the end.It is not even the beginning of the end.But it is,perhaps,the end of the beginning.”4. What are the three technologies that will prepare us for the next pandemic?①manufacturing a vaccine fast②diagnosing a virus at home③developing antiviral drugs④allowing us to intervene earlyA. ①②③B. ①②④C. ①③④D. ②③④5. As far as poorer countries areconcerned,which of the following is TRUE according to this passage?A. pandemic disease is more likely to begin in poorer countriesB. Working from home can work well in poorer countries.C. Health systems are sufficient to care for the infected in poorer countries.D. Virus will cross borders if poorer countries fail to contain it.6. Why is the Second World War mentioned in Para.8?A. The fight against the COVID-19 is similar to the Second World War.B. People are suffering just as they were in the Second World War.C. We should cooperate globally just as we did after the Second World War.D. Countries are fighting each other like in the Second World War.7. What is the tone of this passage?A. pessimisticB. optimisticC. neutralD. indifferentCEvery day in the United States animals are beaten, ignored, or forced to struggle for survival. Left in poor conditions with no food or water, they have little hope as they live out their days without the mercy they deserve. Some are found and rescued, given the chance to experience how great life and humans can be; others aren't so lucky. To grow as a nation, we must fight for these abused(受虐待的) animals’ rights and seriously punish heartless owners.One of the first steps in protecting animals and creating effective cruelty laws is to know what animal cruelty actually is. There are two categories: passive cruelty and active cruelty. The first involves acts of omission, meaning the abuse happens as a result of ignorance or lack of action. Passive cruelty might seem less serious, but that is not the case; it can lead to terrible pain and suffering, and finally death. Examples include starvation, inadequate shelter in extreme weather conditions, and the failure to get medical care. Passive cruelty is sometimes due to the owner's ignorance, so many animal control officers will first try to educate ignorant owners on how to properly care for animals before giving them a citation(传票) or putting them in prison.Active cruelty, on the other hand, is more well-known and disturbing. Sometimes referred to as non-accidental injury, this type of abuse involves purposeful harm on an animal in order to feel more powerful or gain control. Active cruelty against animals should be taken very seriously, since it can be a sign that a person has serious psychological issues and may commit more acts of violence---possibly against humans.It is hard to tell just what drives people to harm innocent animals. Most animal abusers find some sort of achievement or power in torturing a victim that they know can't fight back. While not all animal abusers become serial killers, it is important to take every case seriously.As a nation we need to make it our right to come together and ensure the safety of our beloved pets. As Margaret Mead once said, “Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has.”8. What is the first step to do with the passive cruelty abusers?A. To throw them into prison.B. To bring the case to the court.C. To teach them how to treat animals.D. To give them a strong warning.9. We can learn from Para.3 that active cruelty ______.A. is actually a sign of power or controlB. has been taken seriously in the nationC. may lead to serious psychological problemsD. may cause acts of violence against humans10. What is the author’s attitude towards animal cruelty?A. Uncertain.B. Doubtful.C. Concerned.D. Pessimistic.11. The author wrote this passage to ______.A. warn those heartless pet ownersB. tell people the harm of animal crueltyC. explain the reasons why people harm animalsD. call on people to fight for the abused animalsDAfter finishing his dinner, Lin Xu opened a WeChat mini-program called "Clear Plate" on his phone and took picture of the empty plates. He was then awarded 157 credit points after the image was uploaded and recognized by artificial intelligence.“Users of the app can use their credit to buy gifts, such as books and cellphones to purchase charity meals donated to children in poor rural areas,” Lin said.A nationwide "Clear Your Plate" campaign is gaining steam online. Efforts to stop food waste and promote thrift are also being made by restaurants that have been urged to create an environment in which consumers are reminded not to waste food. They are also encouraged to offer different portion sizes so that customers can have more choices.The “Clear Plate” mini-program has become popular among young Chinese and currently has nearly 1 million users.Liu Jichen, founder of the startup that developed the app, said that the idea popped up at a dinner in 2017, when Liu found that a restaurant would give diners who polished off their food a card and offer small gifts after a certain number of cards had been collected.“Such an idea can be realized online,” Liu said. He formed a team to work on the project.Yet it was quite challenge for the AI system to identify whether the uploaded photos showed empty plates.To make the AI system smarter, Liu and his team, assisted by more than 1,000 others, spent half a year collecting over 100, 000 samples in canteens and restaurants across the country and used the data to train neural network. Dozens of enterprises, institutions and restaurants have contacted the startup to cooperate on the project.Through the visualized mini-program, people can clearly see the good results of saving food, which will effectively reduce waste, he noted. "We hope our efforts can start a new trend among the younger generation, encouraging them to carry out the virtue of cherishing food and developing the habit of thrift, " Liu said12. What is the main function of the APP "Clear Plate?A. Awarding credit points.B. Giving charity meals.C. Showing the empty plates.D. Encouraging saving food.13. How is the "Clear Your Plate" campaign carried out?A. Customers wasting food are punished.B. People join in it on mini-program.C. Restaurants limit customers' choices.D. People are encouraged to buy gifts.14. What was the most difficult when the app was created?A. Getting other people to cooperate with the team.B. Collecting samples in canteens and restaurants.C. Ensuring the app to recognize empty plates.D. Finding people to fund the app.15. What is the purpose of the writing?A. To introduce an app.B. To promote saving food.C. To praise a startup founder.D. To raise fund for poor children.第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。

2020年成都七中初中学校高三英语期中考试试题及答案解析第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AIt looks like 2017 is shaping up to be a record-breaking year in movie History. Here is a list of some of the year’s biggest blockbusters so far.Kong: Skull IslandA reboot (重启) of King Kong would normally get laughed at in this day and age, but it looks like this modem version of the story will be worth watching. With US actress Brie Larson and UK actor Tom Hiddleston in the mix, this film is set to be this year’s biggest monster tale.Release Date:3/10/17Beauty and the BeastDirector Bill Condon is bringing back a part of our childhood in live action, complete with the songs we all remember and love. With British stars Emma Watson and Dan Stevens leading thecast, the classic Walt Disney story already sounds like it’ll be a delight for both children and adults.Release Date:3/17/17The Fate of the FuriousThere was doubt that we’d even get a Fast 8, especially after the fitting ending US actor Paul Walker’s character was given at the end of Furious 7. Fans thought they’d never see Dom and the rest of the crew back in action, but thankfully, US star Vin Diesel himself confirmed that The Fate of the Furious is fueling up for another go.Release Date:4/14/17Spider-Man: HomecomingSpider Man is heading home to Marvel Studios for the first time. The movie will show us Peter Parker’s high school days, and will continue the threads we saw formed during his initial appearance in Captain America: Civil War. We know that Michael Keaton is playing The Vulture in this story, and that both Happy Hogan and Tony Stark, played by US actors Jon Favreau and Robert Downey Jr., are along for the ride.Release Date:7/7/171.Which of the following movies can’t you see on May Day?A.Kong: Skull Island.B.Beauty and the Beast.C.The Fate of the Furious.D.Spider-Man: Homecoming.2.What can we know about Beauty and the Beast?A.It is fueling up for another go.B.It is produced by Marvel StudiosC.It’ll show us Peter Parker’s school days.D.It’ll be enjoyable for both children and adults.3.What does the underlined word “cast” probably mean?A.Characters.B.Actors.C.Directors.D.Teachers.BTaking an afternoon nap could keep your brain sharp, a new study has said. Adults ages 60 and older who took afternoon naps showed signs of better mental ability compared to those who didn’t nap, according to a study published in General Psychiatry earlier this week.Researchers analyzed napping habits in 2, 214 older Chinese people and measured their cognitive abilities using several cognitive tests. Participants took the Mini-Mental State Examination and theBeijingversion of the Montreal Cognitive Assessment, both of which test for memory, language and other cognitive abilities. In every category listed in the study, nappers tested statistically higher on average compared to their non-napping counterparts.Researchers did not gather data from people under 60, so a correlation cannot be drawn between napping and younger generations. The study also noted that there are conflicting studies about the benefits and risks of napping.Sleeping behaviors can be affected by a multitude of factors, said Dr. David Neubauer, associate professor atJohnsHopkinsUniversity. “Daily routines, medication use and sleep disorders can all play a role in how frequently someone takes a nap.” he said.Neubauer recommended taking a shorter “power nap” of up to 20 minutes to decrease the chances of transitioning into slow-wave sleep, which makes people feel groggy when they wake up. “Napping can be a healthy part of an older adult’s day”, Neubauer acknowledged, but make sure “sleepiness isn’t due to a treatable nighttime sleep disorder.” Older individuals who want to do all they can to preserve their cognitive functioning should put nighttime sleep first.4. What is the best way to keep a better cognitive ability for the old?A. Take a nap every day.B. Take sleep disorder seriously.C. Have a good sleep at night.D. Do exercise regularly.5. How did the researchers reach the conclusion?A. By taking the examinations and assessment.B. By analyzing napping habits and giving tests.C. By measuring nappers’ ability and analyzing them.D. By doing an experiment.6. Which has NO effect on one’s sleeping behaviors?A. Taking a nap.B. Medicine treatmentC. Sleep problemsD. Everyday activities.7. What can we know about “slow-wave sleep”?A. It appears in short nap up to 20 minutes.B. People should avoid it in their naps.C. It is a healthy part of an elder’s day.D. It was recommended by Neubauer.CChancellor of the Exchequer George Osborne said yesterday he would use the autumn spending review to increase Britain’s￡12bn-a-year aid budget towards humanitarian(人道主义的) causes in the wake of the European refugee(难民) crisis.Britainpromised to spend 0.7 percent of state general product on aid, meaning the budget could rise sharply by the end of the decade as the economy grows.Mr Osborne also said more of the aid budget could be given to help local government with housing costs for incomers, without breaking international guidelines.“We will use the foreign aid budget to help with the costs of these refugees. People ask about the pressure on public services; we’ll have extra money to help with that.”The government was unable to give a figure for how much aid money could be handed to local authorities: it would depend on how many refugees are accepted.David Cameron, Prime Minister, will set out his position on aid for refugees today. It is reported thatBritainwill accept at least 10,000 extra people from camps on theSyriaborder. He will use a statement in the House of Commons to flesh out plans — announced inMadridon Friday — to take more people.A report inThe Sunday Timesthat the UK would take 15,000 Syrians, not far from the 18,000 figure demanded by the EU, was described by “Downing Street” as a “guess”.TheUKwill offer to resettle Syrians directly from refugee camps inJordan,LebanonandTurkey— but not those who have already reached the EU.8. What is the main idea of the passage?A. Britain tried to help refugees.B. People doubtBritain’s kindness.C. Britain tried to explain its behavior.D. Refugees like to live inBritain.9. What can we infer from the first two paragraphs?A. Britain’s economy grows rapidly.B. Britain will use little of its money to help refugees.C. Most countries are not willing to help refugees.D.Britainwill use more money to help refugees.10. Which of the following statements is TRUE?A. Britain will use foreign money to help refugees.B. Britain helps refugees following international guidelines.C. Britain will use foreign money to develop themselves.D. People ask to use public service money to help refugees.11. What can we know from the passage?A. Britain can hold 10,000 refugees at most.B. The number of refugees to be received is uncertain.C. House of Commons declare a general plan.D.Britaincan hold 15,000 refugees at most.DWhere do you find beauty? Fashion Magazines? Music Videos? One American photographer is finding beauty in unexpected places. And a new documentary about his work might help change the traditional standards of “who” is beautiful.Rick Guidotti put aside his career as a fashion photographer to turn his lens to people living with genetic, physical and behavioral differences. He says what changed his perception of beauty was a chance encounter with an albino （白化病）girl.“I was just tired of people telling me who was beautiful. Every season that face would change but I was always told who was beautiful. As an artist, I don't see beauty just on covers of magazines. I see it everywhere. So it was my initial intention that opened my eyes a little wider and wider.” Said Guidotti.Guidotti has created Positive Exposure, a not-for-profit organization that uses photography and video to transform public views and promote a world where differences are celebrated. Guidotti and Positive Exposure are featured in a new documentary called On Beauty.The cast and crew recently hosted a screening at Georgetown University in Washington. One of the women featured in the film is Jayne Waithera. “I never thought I was beautiful because nobody said that to me, but meeting him was my profound moment. I remember that particular day he took my picture and I felt so good like I felt there's somebody who, really loves me and sees me for who I am and who sees me more than my condition.” said Waithera.The documentary is the idea of producer Joanna Rudnick. After seeing Guidotti's photos, she decided to tell his story. Joanna and Guidotti are traveling from city to city to promote On Beauty. “As I travel from community to community, I'm taking photographs and I'm encouraging individuals with a positive sense of who they are. They're seeing beauty in their reflection but I'm also encouraging their families and they in turn are encouraging their communities as well. All is based on the philosophy of change how you see,see how you change.”12. What made Rick change his understanding of beauty?A. A girl diagnosed with albino.B. His job as a fashion photographer.C. The beauty on the covers of magazines.D. Influence from the people working with him.13. What can we infer about Jayne Waithera?A. She showed great interest in taking photos.B. She used to be disappointed at her work and life.C. She was greatly influenced by the experience with Rick.D. She believed Rick was the best photographer in the world.14. Which of the following words can best describe On Beauty?A. abstract and differentB. traditional and academicC. tolerant and encouragingD. creative and interesting15. What's the best title of the text?A. True Beauty In The Eye Of A PhotographerB. Beautiful Or Not Beautiful,That's A QuestionC. Be Who You Are Not Who You Want To BeD. A Different photographer, A Different Magazine第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。

四川省成都市温江区七中实验学校2020-2021学年七年级上学期期中数学试题学校:___________姓名：___________班级：___________考号：___________一、单选题1．如果零上2C ︒记作2C +︒，那么零下3C ︒记作（ ）A ．2C +︒B ．2C -︒ C ．3C +︒D ．3C -︒ 2．下列四个立体图形中，主视图为圆的是（ ）A ．B ．C ．D ． 3．粤海铁路是我国第一条横跨海峡的铁路通道，设计年输送货物能力为11000000吨，用科学记数法应记为（ ）A ．61110⨯吨B ．71.110⨯吨C ．71110⨯吨D ．81.110⨯吨 4．下列哪个图形是正方体的展开图（ ）A ．B ．C ．D ．5．下列比较大小，正确的是( )A ．－3＜－4B ．－(－3)＜|－3|C ．－12＞－13D ．1||6- >－17 6．下列说法正确的是( )①有理数包括正有理数和负有理数；②相反数大于本身的数是负数；③数轴上原点两侧的数互为相反数；④两个数比较，绝对值大的反而小；A ．②B ．①③C ．①②D ．②③④ 7．下列判断中，错误的是( )A ．1a ab --是二次三项式B ．22a b c -是单项式C ．2a b +是多项式D ．34R π中，系数是348．已知整式22x x -的值为3，则2246x x -+的值为（ ）A ．7B ．9C ．12D ．189．若323m a b --与12n b a +是同类项，则m 、n 的值分别为（ ）A ．1,1B ．5,3C ．5,1D ．-1,-110．下列图形都是由同样大小的黑色正方形纸片组成，其中第①个图中有3张黑色正方形纸片，第②个图中有5张黑色正方形纸片，第③个图中有7张黑色正方形纸片，…，按此规律排列下去第⑥个图中黑色正方形纸片的张数为（ ）A ．11B ．13C ．15D ．17二、填空题 11．计算：2223-+⨯=______．12．去括号合并：(3)3(3)a b a b --+＝_________.13．12-的相反数是________，－1.5的倒数是________． 14．在数轴上，与原点距离为6的点所表示的数是____．15．多项式12x |m|﹣（m ﹣3）x+6是关于x 的三次三项式，则m 的值是_____． 16．a 、b 互为相反数，c 、d 互为倒数，则()11323a b cd -+--=________． 17．一个几何体，是由许多规格相同的小正方体堆积而成的，其正视图、左视图如图所示，要摆成这样的图形，最少需用___________个正方体．18．已知,,a b c 在数轴上的对应点如图所示，化简a a b c a b c -++-++=__________.19．如图是一个运算程序的示意图，若开始输入x 的值为81，则第2019次输出的结果为 ______.三、解答题20．计算：(1)－4＋2×|－3|－(－5)；(2)－3×(－4)＋(－2)3÷(－2)2－(－1)2 018.21．先化简，再求值：22362(42)31x y xy xy x y ⎡⎤---++⎣⎦，其中1,12x y =-= 22．已知关于x 、y 的多项式x 2y m+1+xy 2–3x 3–6是六次四项式，单项式6x 2n y 5–m 的次数与这个多项式的次数相同，求m+n 的值．23．蜗牛从某点A 开始沿一东西方向直线爬行，规定向东爬行的路程记为正数，向西爬行的路程记为负数．爬过的各段路程依次为（单位：厘米）：－6，+12，－10，+5，-3，+10，-8．（1）通过计算说明蜗牛是否回到起点A ．（2）在爬行过程中，如果每爬1厘米奖励2粒芝麻，则蜗牛一共得到多少粒芝麻？ 24．画出数轴且在数轴上表示下列各数，并把它们按照从小到大的顺序排列：3， ()1--， -1.5，0，2--，132- 25．已知22423A x xy x =+--，22B x xy =-++．（1）请求出36A B +的值.（2）若36A B +的值与x 无关，请求出y 的值.26．如图是由5个相同的小正方体搭成的几何体，已知小正方体的棱长为1．（1）画出它的三视图；（2）求出它的表面积（含底面积）.27．分别用 a ，b ，c ，d 表示有理数，a 是最小的正整数，b 是最大的负整数，c 是绝对值最小的有理数，d 是数轴上到原点距离为3的点表示的数；（1）直接写出 a ，b ，c ，d 的值；（2）求4a 3b 2c d +++的倒数．．. 28．某市居民使用自来水接如下标准收费（水费按月缴纳）（1）某用户一个月用了15m 3水，求该用户这个月应缴纳的水费；（2）设某户月用水量为"n”立方米，当n>18时，求该用户应缴纳的水费(用含n 的代数式表示)；（3）甲、乙两用户一个月共用水36m 3，已知甲用户缴纳的水费超过了20元．设甲用户这个月用水xm 3，直接写出甲、乙两用户一个月共缴纳的水费(用含x 的代数式表示)．参考答案1．D【分析】根据有理数的意义即可求解.【详解】零上2C ︒记作2C +︒，那么零下3C ︒记作3C -︒故选D.【点睛】此题主要考查正负数的意义，解题的关键是熟知有理数的意义.2．B【详解】解：因为圆柱的主视图是矩形，圆锥的主视图是等腰三角形，球的主视图是圆，正方体的主视图是正方形，所以，主视图是圆的几何体是球．故选B ．考点：简单几何体的三视图．3．B【分析】科学记数法就是将一个数字表示成（a×10的n 次幂的形式），其中1≤a ＜10，n 表示整数．n为整数位数减1，即从左边第一位开始，在首位非零的后面加上小数点，再乘以10的n 次幂．【详解】由科学记数法得：11000000＝1.1×107． 故选B ．【点睛】本题考查学生对科学记数法的掌握．科学记数法要求前面的部分的绝对值是大于或等于1，而小于10，小数点向左移动7位，应该为1.1×107． 4．B【分析】根据正方体展开图的11种特征，选项A 、C 、D 不是正方体展开图；选项B 是正方体展开图的“1-4-1”型．【详解】根据正方体展开图的特征，选项A、C、D不是正方体展开图；选项B是正方体展开图．故选B．【点睛】正方体展开图有11种特征，分四种类型，即：第一种：“1-4-1”结构，即第一行放1个，第二行放4个，第三行放1个；第二种：“2-2-2”结构，即每一行放2个正方形，此种结构只有一种展开图；第三种：“3-3”结构，即每一行放3个正方形，只有一种展开图；第四种：“1-3-2”结构，即第一行放1个正方形，第二行放3个正方形，第三行放2个正方形．5．D【分析】根据有理数大小的比较方法进行分析判断即可.【详解】A选项中，因为34->-，所以A中式子不成立；B选项中，因为(3)33--==-，所以B中式子不成立；C选项中，因为1123-<-，所以C中式子不成立；D选项中，因为111667-=>-，所以D中式子成立.故选D.【点睛】熟知“有理数大小的比较方法：（1）正数都大于零，负数都小于零，正数大于负数；（2）两个负数比较大小,绝对值大的反而小”是解答本题的关键.6．A【解析】试题解析：①有理数包括正有理数和负有理数.错误.还有零.②相反数大于本身的数是负数.正确.③数轴上原点两侧的数互为相反数.错误.例如3-和2.④两个数比较，绝对值大的反而小.错误.两个负数,绝对值大的反而小.故选A.7．D【分析】直接利用单项式的系数以及多项式的次数与项数确定方法分别分析得出答案；【详解】A 选项：1−a−ab 是二次三项式，正确，不合题意；B 选项：22a b c -是单项式，正确，不合题意；C 选项：2a b +是多项式，正确，不合题意；D 选项：34R π中，系数是34π，故此选项错误，符合题意； 故答案为D.【点睛】本题主要考查了单项式，多项式的定义，掌握单项式和多项式的定义是解题的关键. 8．C【分析】先把代数式进行适当的变形，然后直接把已知整式代入代数式即可求出代数式的值.【详解】 原式＝222462(2)623+612x x x x -+-+⨯＝＝＝【点睛】本题主要考查整体带入的数学思想，用整体代入方法是本题的解题的关键.9．C【分析】根据同类项的定义(所含字母相同,相同字母的指数相同)列出方程,求出n,m 的值.【详解】∵323m a b -－与12n b a +是同类项,∴m -3=2,2=n+1,∴m=5,n=1.故选C.本题考查同类项的定义,所含字母相同且相同字母的指数也相同的项是同类项.注意同类项定义中的两个“相同”:(1)所含字母相同;(2)相同字母的指数相同.10．B【分析】仔细观察图形知道第一个图形有3个正方形，第二个有5=3+2×1个，第三个图形有7=3+2×2个，由此得到规律求得第⑥个图形中正方形的个数即可．【详解】观察图形知：第一个图形有3个正方形，第二个有5=3+2×1个，第三个图形有7=3+2×2个，…故第⑥个图形有3+2×5=13（个），故选B．【点睛】此题主要考查了图形的变化规律，是根据图形进行数字猜想的问题，关键是通过归纳与总结，得到其中的规律，然后利用规律解决一般问题．11．2【分析】先根据有理数乘方法则进行乘方运算,再根据有理数乘法法则计算乘法,再根据有理数的加法进行计算即可.【详解】2223-+⨯,=-4+6,=2,故答案为:2.【点睛】本题主要考查有理数混合运算,解决本题的关键是要熟练掌握运算顺序和运算法则.【解析】【分析】先去括号，然后再合并同类项即可得.【详解】()()3a b3a3b--+=3a-b-3a-9b=-10b，故答案为-10b.【点睛】本题考查了整式的加减，熟练掌握去括号法则以及合并同类项法则是解题的关键.13．12-23-【分析】根据相反数和倒数的定义进行求解即可. 【详解】解：∵1122-=，31.52-=-，∴12-的相反数是12-，－1.5的倒数是23-，故答案为：12-，23-.【点睛】本题考查了求一个数的相反数和倒数，正确把握定义是解题关键.14．±6【解析】距离原点距离为6的点表示的数有两个，分别在原点左右两侧，为6和-6.故答案为±6.点睛：一般地，设a是一个正数，数轴上与原点距离是a的点有两个，它们分别在原点左右两侧，表示为-a和a，这两点关于原点对称.15．-3由题意可知：|m|=3，且m-3≠0即可作答.【详解】由题意可知：|m|=3，且m-3≠0；∴m= -3；故答案为-3．【点睛】本题考查了单项式与多项式的概念，掌握一个单项式中，所有字母的指数的和叫做这个单项式的次数.多项式中每个单项式叫做多项式的项，这些单项式中的最高次数，就是这个多项式的次数是解题的关键.16．5 6 -【分析】由a、b互为相反数，c、d互为倒数可知a+b=0，cd=1，然后代入求值即可．【详解】∵a、b互为相反数，c、d互为倒数，∴a+b=0，cd=1，∴原式=﹣3×0﹣112⨯﹣13=﹣56．故答案为﹣56．【点睛】本题主要考查的是有理数的运算，根据题意得到a+b=0，cd=1是解题的关键．17．6【解析】【分析】根据主视图、左视图是分别从物体正面、左面看，所得到的图形，画出俯视图即可解决问题．【详解】根据三视图可得：第二层有2个小正方块，根据主视图和左视图可得第一层最少有4个正方体，故最少需用6块正方体；（俯视图如下）故答案为6．【点睛】本题考查了学生对三视图掌握程度和灵活运用能力，同时也体现了对空间想象能力方面的考查．如果掌握口诀“主视图疯狂盖，左视图拆违章”就更容易得到答案．18．a【解析】【分析】根据数轴先确定+a b ，c a -，b c +的符号，再根据去绝对值的方法进行化简.【详解】由数轴可得+a b ＜0，c a -＞0，b c +＜0， ∴a a b c a b c -++-++=a+a+b+c-a-b-c=a故填：a.【点睛】此题主要考查绝对值的应用，解题的关键是去绝对值的方法.19．3【分析】根据运算程序进行计算，然后得到规律：从第3次开始，奇数次运算输出的结果是3，偶数次运算输出的结果是1，然后根据第2019次是奇数次可得出结果．【详解】解：第1次，13×81＝27， 第2次，13×27＝9， 第3次，13×9＝3， 第4次，13×3＝1， 第5次，1＋2＝3，第6次，13×3＝1， …， 依此类推，∵2019÷2＝1009…1， ∴第2019次输出的结果为3，故答案为：3．【点睛】本题考查了代数式求值以及数字类规律探索，根据运算程序计算出前几次的结果，进而得出规律是解题的关键．20．(1)7；(2)9【分析】（1）注意运算顺序，先算乘除再算加减，减去一个数等于加上这个数的相反数，减法变为加法；（2）注意运算顺序，先算乘方再算乘除最后算加减.注意()201811-=，1-的偶次方为1，奇次方为1-.【详解】(1)原式＝－4＋2×3＋5＝－4＋6＋5＝7；(2)原式＝12＋(－8)÷4－1＝12－2－1＝9.【点睛】本题考查了有理数的混合运算，注意：要正确掌握运算顺序，即乘方运算叫做三级运算；乘法和除法叫做二级运算；加法和减法叫做一级运算.在混合运算中要特别注意运算顺序：先三级，后二级，再一级；有括号的先算括号里面的；同级运算按从左到右的顺序.21．2xy-3；-4.【分析】去括号，合并同类项得到最简结果，然后代入求值即可.【详解】解：原式()22368431x y xy xy x y =--+++ 22368431x y xy xy x y =-+--+23xy=-；当1,12x y=-=时，原式12()131342=⨯-⨯-=--=-.【点睛】本题考查了整式加减－化简求值，熟练掌握去括号和合并同类项的法则是解题关键.22．m+n=5【分析】根据多项式次数的定义可得2+m+1=6，求出m=3，然后再根据单项式次数的定义可得2n+5-m=6，求出n=2，问题得解.【详解】解：∵多项式x2y m+1+xy2–3x3–6是六次四项式，∴2+m+1=6，解得：m=3，∵单项式6x2n y5–m的次数也是六次，∴2n+5-m=6，解得：n=2，∴m+n=3+2=5.【点睛】本题考查了多项式以及单项式的有关概念，注意：多项式中次数最高的项的次数叫多项式的次数．23．(1) 回到了起点A；(2)108粒【分析】（1）将各段路程相加，看结果是否为0，为0则回到了起点A；（2）将各段路程的绝对值相加，然后乘以2即可得到结果.【详解】解：（1）-6+12-10+5-3+10-8=0，故蜗牛回到了起点A；（2）（6+12+10+5+3+10+8）×2=108（粒），答：蜗牛一共得到108粒芝麻.【点睛】本题考查了有理数加法的实际应用以及正负数的意义，解题关键是理解“正”和“负”的相对性，明确什么是一对具有相反意义的量．在一对具有相反意义的量中，先规定其中一个为正，则另一个就用负表示．24．数轴及数轴上表示下列各数见解析，()132 1.50132------＜＜＜＜＜【分析】先分别化简各数，再把各个数在数轴上画出表示出来，根据数轴上的数右边的数总是大于左边的数，即可把各个数按由小到大的顺序用“＜”连接起来．【详解】∵()11--=，21--=-，132- ∴在数轴上表示下列各数如图所示：数轴上的点表示的数右边的总比左边的大，得：()132 1.50132------＜＜＜＜＜． 【点睛】本题考查了有理数大小比较，利用数轴上的点表示的数右边的总比左边的大是解题关键． 25．(1) 1863xy x -+ ;(2) 13y =. 【解析】【分析】(1)将A 与B 代入36A B +中,去括号合并即可得到结果;(2)根据36A B +的值与x 的值无关,得到x 的系数为0,即可求出y 的值.【详解】（1）()()22223632423626126966121863A B x xy x x xy x xy x x xy xy x +=+--+-++=+---++=-+（2）原式()18631863xy x y x =-+=-+要使原式的值与x 无关，则1860y -=，解得：13y =． 【点睛】本题考查了整式的化简求值，解题的关键是熟练掌握去括号法则，合并同类项的法则.26．（1）见解析；（2）22S =表【解析】试题分析：（1）利用小正方体堆成的几何体形状得出个数即可；（2）利用三视图求出六个方向的表面积即可．试题解析：（1）如图，（2）表面积为：4+4+3+3+4+4=22.27．（1）a=1,b=-1,c=0,d=3或-3；（2）14或1-2 【分析】（1）根据有理数的相关概念可直接确定a 、b 、c 、d 的值；（2）分情况求4a 3b 2c d +++的值，然后再求其倒数即可．【详解】解：（1）∵a 是最小的正整数，b 是最大的负整数，c 是绝对值最小的有理数，d 是数轴上到原点距离为3的点表示的数，∴a=1，b=-1，c=0，d=3或-3；（2）当d ＝3时，4a ＋3b ＋2c ＋d ＝4×1＋3×（−1）＋2×0＋3＝4， 所以4a ＋3b ＋2c ＋d 的倒数是14； 当d ＝−3时，4a ＋3b ＋2c ＋d ＝4×1＋3×（−1）＋2×0−3＝−2，所以4a ＋3b ＋2c ＋d 的倒数是：12-， 综上所述：4a ＋3b ＋2c ＋d 的倒数是：14或12-． 【点睛】本题考查了有理数、绝对值、倒数的相关知识及有理数的混合运算，题目综合性较强．解决本题的关键是确定a 、b 、c 、d 的值．注意：最小的正整数是1，没有最小的正数；最大的负整数是−1，没有最大的负数；绝对值最小的有理数是0，绝对值是它本身的数是正数和0；倒数是它本身的数是±1．28．（1）35（元）；（2）4n-28（元）；(3)①当10<x≤18时，缴纳的水费为106-x（元）；②当x>18，0<36-x≤10时，缴纳的水费为2x+44（元）；③当x>18，10<36-x<18时，缴纳的水费为x+70（元）.【分析】（1）根据收费标准进行计算即可；（2）根据收费标准列代数式即可；（3）根据甲用户缴纳的水费超过了20元可知甲用户的用水量大于10m3，然后分情况讨论：①当10<x≤18时，则18≤36-x，②当x>18，0<36-x<10时，③当x>18，10<36-x<18时，分别根据收费标准列出代数式即可.【详解】解：（1）10×2+（15-10）×3＝20+15＝35（元），答：该用户这个月应缴纳水费35元；（2）∵n>18，∴该用户应缴纳的水费为：10×2+（18-10）×3+（n-18）×4＝20+24+4n－72＝4n－28（元）；（3）∵甲用户缴纳的水费超过了20元，∴甲用户的用水量大于10m3，分情况讨论：①当10<x≤18时，则18≤36-x，此时共缴纳的水费为：10×2+（x-10）×3+4×（36-x）-28＝106-x（元）；②当x>18，0<36-x≤10时，此时共缴纳的水费为：4x－28+（36-x）×2＝2x+44（元）；③当x>18，10<36-x<18时，此时共缴纳的水费为：4x－28+10×2+（36-x-10）×3＝x+70（元）.【点睛】本题考查了有理数混合运算的实际应用以及列代数式等知识点，正确理解收费标准，针对不同情况分类讨论是解题的关键．。

成都七中实验学校（初中部）2020年化学上册期中试题及答案一、选择题（培优题较难）1．现有 18.6g NaOH 和 Na2CO3固体混合物，已知钠元素与碳元素的质量比 23：3，则原混合固体中含有钠元素的质量为（）A．9.2 g B．6.9 g C．4.6 g D．2.3 g2．下列有关燃烧和灭火说法正确的是A．油锅着火后向锅中放入菜叶目的是降低油的着火点B．家用煤加工成蜂窝煤是力了增大煤与氧气的接触面积C．高层建筑物起火立即乘电梯撤离D．不慎碰倒了酒精灯，酒精在桌面燃烧，用水来灭火3．下列实验操作正确的是A．塞紧橡皮塞B．加热液体C．取用液体D．读出液体的体积4．最近，我国科学家成功合成新型催化剂，将CO2高效转化为甲醇（CH3OH）。

这不仅可以缓解碳排放引起的温室效应，还将成为理想的能源补充形式。

该化学反应的微观过程如下图所示。

下列说法正确的是A．该反应中四种物质均为化合物B．反应前后H元素的化合价不变C．参加反应的甲、乙分子个数比为1:3D．反应前后原子数目发生改变5．2017年10月27日央视财经报道：王者归“铼”，中国发现超级金属铼，制造出航空发动机核心部件。

如图是铼在元素周期表中的相关信息，下列有关说法不正确的是（）A．铼原子的核内质子数为75 B．铼的相对原子质量为186.2gC．铼的元素符号是Re D．铼原子的核外电子数为756．宏观辨识和微观剖析是化学核心素养之一。

下列说法正确的是 ( )A．反应前后元素的种类及化合价均未发生改变B．参加反应的和的微粒个数比是4:3C．反应涉及到的物质中,是由原子构成的单质,只有属于氧化物D．该反应生成的单质和化合物的质量比时3：207．下列图示中的“错误实验操作”与图下面对应的“可能产生的后果”不一致的是（）A．液体喷出B．污染试剂C．酒精溅出D．读数偏大8．碳酸乙烯酯(C3H4O3)可用作锂电池电解液，下列有关碳酸乙烯酯的说法正确的是A．碳酸乙烯酯的相对分子质量为(12×3+1×4+16×3)gB．碳酸乙烯酯中C、H、O三种元素的质量比为12:1:16C．碳酸乙烯酯中C、H、O三种原子的个数比为3:4:3D．碳酸乙烯酯中碳元素的质量分数= ×100%9．下列有关水的说法中正确的是（）A．水与冰块混合得到混合物B．水的蒸发和水通电分解都属于物理变化C．硬水是指含有较多可溶性钙、镁化合物的水D．水沸腾时可冲起壶盖，说明温度升高分子会变大10．以下是实验室制取、收集、干燥、存放气体的装置图，有关说法错误的是A．实验室用双氧水制取氧气，用石灰石和稀盐酸制取二氧化碳均可使用装置②B．实验室收集氧气和二氧化碳均可使用装置③，气体从导管b进入C．实验室干燥氧气和二氧化碳均可使用装置④，气体从导管a进入D．实验室收集的氧气和二氧化碳，均可如图⑤临时存放11．甲、乙、丙、丁四种物质在反应前后的质量关系如图所示，下列有关说法错误的是A．参加反应的甲和乙质量比为2:7 B．丙可能是该反应的催化剂C．丁一定是化合物D．x的值是712．下列实验基本操作错误的A．B．C．D．13．下列实验操作正确的是A．塞紧胶塞B．贮存氧气C．过滤D．吹灭酒精灯14．1869年门捷列夫编制了元素周期表。

四川省成都市七中实验学校2020 学年七年级语文放学期期中试题注意事项：1．本试卷分 A 卷、 B 卷； A 卷总分 100 分， B 卷总分 50 分，全卷总分 150 分。

考试时间 120 分钟。

2．在作答前，考生务势必自己的姓名、准考据号涂写在答题卡规定的地方，考试结束后监考人员只收取答题卡。

3．选择题部分一定使用2B 铅笔填涂，假如需要改正用橡皮檫将错误答案檫干净后再从头填涂答案；非选择题部分一定使用0．5 毫米黑色的署名笔书写，字体工整、字迹清楚。

4．请依照题号在答题卡上各题目对应的答题地区内作答，高出答题地区书写的答案无效；在底稿纸、试卷上答题无效。

5．保持答题卡洁净，不得折迭、污染、损坏等。

A卷(共100分)第I卷(选择题，共24分)一、基础知识 (每题3分，共12分)1．下边加点字注音完好正确的一项为哪一项（）A．厌恶（ zēngè）诘责（jí）震悚（sǒng）．．．．B．愧怍（kuìzu ò）门框（kuāng）晌午(xiǎng)．．．．取消（dì）．门槛 (k ǎn)．C．凝望 (líng)．D．鄙陋（wěi suǒ）．．ào)矜持(j īn ch í)怀恋(niàn)书斋(zāi)．．．粗糙 (zhu ō)惊恐(huáng)笼盖(lǒng zh ．．．．2．以下语句中书写完好正确的一项为哪一项（）A．父亲闲着没什么事可干，又感觉很烦燥。

他那颗很倔的头颅埋在膝盖里半响都没动。

B．有一天夜晚，我们夫妻漫步，经过一个荒辟的小胡同，看见一个破败落落的大院，里面有几间蹋败的小屋。

C．我浸在这繁密的花朵的光芒中，其他全部临时都不存在，有的不过精神的宁静和生的愉悦。

D．但我却选了此外一条路，它荒草凄凄，十分悠寂，显得更诱人，更漂亮。

3．以下语句中加点的成语使用无误的一项为哪一项（）A．看到他这类风趣的表情，坐在身边的一名外国记者忍俊不由地笑起来。

2019-2020学年四川省成都七中实验学校七年级（上）期中地理试卷一、选择题（共25小题，每小题2分，满分50分）1. 人类对地球形状的认识，经历了漫长的过程。

下列认识过程排序正确的是（）①地球卫星照片②天圆地方③麦哲伦船队环球航行④根据太阳和月亮形状推测A.①②③④B.③②①④C.②④③①D.④②①③2. 下列各点中，符合“北半球、低纬度、东半球”三个条件的是（）A.20°E，60°NB.180°，17°NC.0°，26°ND.19°W，15°S3. 在地球仪上，0°代表的意思不可能是（）A.纬线的起点B.赤道C.本初子午线D.北极点4. 东西半球的分界线是（）A.20°N，160°SB.20°W，160°EC.20°N，160°SD.20°E，160°W5. 太阳能直射的最北界线是（）A.23.5°SB.66.5°NC.23.5°ND.66.5°S6. 地球仪上，最长的纬线是（）A.赤道B.本初子午线C.南回归线D.北极圈7. 地球上存在时间差异的原因是（）A.地球是个球体B.地球不透明C.地球在自转D.地球在公转8. 地球上，四季变化比较明显的地区是（）A.热带B.温带C.寒带D.南寒带9. 地球的平均半径是（）A.6378千米B.6371千米C.6357千米D.4万千米10. 南极圈的纬度是（）A.60°SB.23.5°SC.66.5°SD.66.5°N 11. 世界上的最高峰的海拔是8844.43米，它与世界最低洼的死海的相对高度是9236.43米，据此推测世界最低洼地的海拔为（）A.392米B.﹣392米C.0米D.不能确定12. 在1：10000000的地图上，甲地与乙地的图上距离是5厘米，两地的实际距离是（）A.20千米B.50千米C.200千米D.500千米13. 到海南旅游，最好选用的地图是（）A.世界政区图B.中国政区图C.海南省旅游图D.海南省地形剖面图14. 地图上的指向标通常指向（）A.东方B.西方C.南方D.北方15. 有一位建筑师，想要建造一座房子，如果要四面朝北方，应当建在（）A.北极点上B.南极点上C.赤道上D.不能修建16. 在分层设施地形图上，绿色一般代表（）A.平原B.山地C.高原D.丘陵17. 图幅相同的地图，下列比例尺中表示内容最详细的是（）A.1：5000000B.110000000C.五十万分之一D.一百万分之一18. 南北半球的分界线是（）A.赤道B.本初子午线C.南回归线D.北回归线19. 下列关于纬线的叙述正确的是（）A.北纬用字母“S”表示B.地球仪上有无数条纬线C.纬线指示东西方向D.所有纬线长度都相等20. 下列有关经线的叙述正确的是（）A.所有的经线都是圆B.经线的长度有长有短C.经线指示的是南北方向D.经线穿过地心并垂直于纬线21. 地球表面陆地面积占地球总面积的（）A.29%B.39%C.37%D.71%22. 世界最大的大洲和最大的大洋分别是（）A.非洲和太平洋B.亚洲和大西洋C.亚洲和太平洋D.欧洲和大西洋23. 纬度位置最高的大洲和大洋分别是（）A.亚洲和印度洋B.南极洲和北冰洋C.大洋洲和太平洋D.南极洲和大西洋24. 下列地理事物属于亚洲与欧洲分界线的是（）A.苏伊士运河B.乌拉尔山C.巴拿马运河D.红海25. 在等高线地形图上，某处等高线呈弯曲状，若曲线向高处方向凸出时，该处的地形部位应是下列的（）A.鞍部B.山脊C.陡崖D.山谷二、填空题（共4小题，满分10分）26地图的基本要素是________、________和________．27 中国地图与成都地图相比较，成都地图的比例尺________（大/小）、表示的地图范围________（大/小）、表示的内容越________（详/略）。

Thisismyfamily.__51．____Iamtheonly（唯一）child.Mymotherisateacher.__52．___Youcanseetheminourschool.MyfatherandIusuallygotoschoolbycarinthemorningtogether.__53．___
56．A．ChineseB．AmericanC．school
57．A．toB．withC．in
58．A．familyB．fullC．first
59．A．schoolB．phoneC．family
60．A．HerB．He’sC．His
61．A．amB．isC．are
62．A．schoolbagB．pencil boxC．watch
35．A．WhatB．IsC．What's
36．A．IsB．AreC．Do
37．A．/B．aC．an
38．A．amB．isC．be
39．A．orangeB．redC．black
40．A．sayB．meetC．spell
完成对话，在对话空格中填入适当的单词，使对话完整正确。一空一词。 将答案按编号依次填入表格内。（共10小题，每小题1分；计10分）
63．A．erasersB．dictionariesC．watches
64．A．hisB．hersC．mine
65．A．withB．atC．for
五、阅读判断
阅读理解（共15小题，每小题2分；计30分）
阅读下面短文，根据短文内容判断句子的正误，正确地写A错误的写B。（共5小题，每小题2分；计10分）。
短文填空。从下面方框中选出10个单词，用它们的适当形式填入短文空格内，使短文意思正确、通顺（每词限用一次）。将答案按编号依次填入表格内。（共10小题,

2020年成都七中初中学校高三英语下学期期中考试试卷及参考答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项AMy wife Hilary andI were on the beach, with three of our children, taking pictures of shore birds near our home in Alaska when we saw a bear. The bear was thin and small, moving aimlessly.Just a few minutes later, I heard my daughter shouting, “Dad! The bear is right behind us!" An aggressive bear will usually rush forward to frighten away its enemy but would suddenly stop at the last minute. This one was silent and its ears pinned back the sign of an animal that is going in for the kill. And it was a cold April day. Thebear behaved abnormally, probably because of hunger.I held my camera tripod(三脚架)in both hands to form a barrier as the bear rushed into me. Its huge head was level with my chest and shoulders, and the tripod stuck across its mouth. It bit down and I found myself supporting its weight. I knew 1 would not be able to hold it for long.Even so, this was a fight I had to win: I was all that stood between the bear and my family, who would stand little chance of running faster than a brown bear.The bear hit at the camera, cutting it off the tripod. I raised my left arm to protect my face; the beast held tightly on the tripod and pressed it into my side. My arm could not move, and I sensed that my bones were going to break.Drawing back my free hand, I struck the bear as hard as I could for five to six times. The bear opened its mouth and I grasped its fur, trying to push it away. I was actually wrestling with the bear at this point. Then, as suddenly as it had begun, the fight ended. The bear moved back towards-the forest,before returning for another attack the first time I felt panic.Obviously satisfied that we caused no further threat, the bear moved off, destroying a fence as it went. My arm was injured, but the outcome for us could hardly have been better. I'm proud that my family remained clear-headed when panic could have led to a very different outcome.1. How did the writer feel when faced with the brown bear?A. Fearful but confident.B. Nervous but brave.C. Upset but determined.D. Awful but hopeful.2. The bear finally went away after itA. got injuredB. felt safeC. found some foodD. took away the camera3. What does the author want to tell us?A. We should keep calm when troubles comeB. We should rise to the challenge when faced with difficulties.C. We should not risk ourselves in some dangerous areas.D. We should learn to take advantage of anything at hand when in trouble.BWhere doyou usually put your toothbrush?Do you keep it in the bathroom? How’s your toothbrush looking these days? Even if you can’t see it with a naked eye, experts say it may be saturated(使饱和)with millions of toilet germs!Dr. Charles Oerba, a germ expert, is amicrobiology professor at the University of Arizona. He says there are approximately 3 million bacteria per square inch in most toilet bowls, and every time you flush it without closing the lid, those millions of bacteria droplets spray into the air as far as twenty feet away and dirty everything in their path. And a common victim is your poor toothbrush, usually, left out on the bathroom sink, right?So, what do we do? Dr. Gerba says it’s easy. Close the toilet lid before you flush—that’ll greatly cut downthe germs, which will otherwise float in the air. And wash your toothbrush every few days in mouthwash or peroxide to get rid of any germs hiding in it. You can even put it through the dishwasher to sanitize(消毒)it. And always store your toothbrush in a closed cabinet.Here’s one more tip from Dr. Gerba, who says our kitchen sink is probably dirtier than our toilet. “If an alien came from space and studied the bacterial counts, he probably would conclude he should wash his hands in your toilet and go to the bathroom in your sink.” He says that’s because the kitchen sink is a great place where E. coli(大肠杆菌)to live and grow since it’s wet and damp. Bacteria feed on the food that people put down the drain or—that’s left on dishes in the sink. To reset your sink’s bacteria count back to zero, you’d better regularly wash it with hot water and sanitize yoursink with special chemicals. In fact, you may want to do it every day or before preparing dinner.4. What is the purpose of the text?A. To show how to brush your teeth.B. To tell people the importance of health.C. To warn people of the invisible germs.D. To introduce a microbiology professor.5. What can we learn from Paragraph 2?A. Bathroom sinks are the dirtiest places.B. Bacteria are bad for people’s health.C. Why bacteria spread through the air.D. How bacteria spread in the bathroom.6. What does the underlined word“that”in Paragraph 4 refer to?A. The food.B. The toothbrush.C. The sink.D. The chemical.7. Why does Dr. Gerba mention the example of an alien?A. To tell us a fiction story of an alien studying bacteria.B. To show our kitchen sink may be dirtier than our toilet.C. To teach us how to reset sink’s bacteria count back to zero.D. To prove coli prefers to live in the kitchen and the drain.CBill Gates on how to fight future pandemicsWHEN HISTORIANS write the book on the covid-19 pandemic, what we've lived through so far will probably take up only the first third or so.The bulk of the story will be what happens next.I believe that humanity will beat this pandemic, but only when most of the population is vaccinated(接种疫苗）.Until then, life will not return to normal.As the pandemic slows in developed nations,itwill accelerate in developing ones.Their experience,however,will be worse.In poorer countries,where fewer jobs can be done remotely,distancing measures won't work as well.The virus will spread quickly,and health systems won't be able to care for the infected.Wealthy nations can help.But people in rich and poor places alike will be safe only once we have an effective medical solution for this virus,which means a vaccine.My hope is that,by the second half of 2021,facilities around the world will be manufacturing a vaccine.If that's the case,it will be a history-making achievement: the fastest humankind has ever gone from recognizing a new disease to immunizing（免疫）against it.Apart from this progress in vaccines,two other big medical breakthroughs will emerge from thepandemic.One will be in the field of diagnostics.The next time a novel virus crops up,people will probably be able to test for it at home.Researchers could have such a test ready within a few months of identifying a new disease.The third breakthrough will be in antiviral drugs.We haven't been as effective at developing drugs to fight viruses as we have those to fight bacteria.But that will Researchers will develop large diverse libraries of antivirals,which they'll be able to scan trough and quickly find effective treatments for novel viruses.All three technologies will prepare us for the next pandemic by allowing us to intervene(干预）early when the number of cases is still very low.Our progress won't be in science alone.It will also be in our ability to make sure everyone benefits from that science.In the years after 2021,I think we'll learn from the years after 1945. With the end of the Second World War, leaders built international institutions like the UN to prevent more conflicts.After covid-19, leaders will prepare institutions to prevent the next pandemic.These will be a mix of national,regional and global organizations.I expect they will participate in regular"germ games”in the same way as armed forces take part in War games.These will keep us ready for the next time a novel virus jumps from bats or birds to humans.I hope wealthy nations include poorer ones in these preparations,especially by devoting more foreign aid to building up their primary health-care systems.This pandemic has shown us that viruses don't obey border laws and that we are all connected biologically by a network of microscopic germs,whether we like it or not.The best analogy(类比）for today might be November 10th 1942.Britainhad just won its first land victory of the war,and Winston Churchill declared in a speech: “This is not the end.It is not even the beginning of the end.But it is,perhaps,the end of the beginning.”8. What are the three technologies that will prepare us for the next pandemic?①manufacturing a vaccine fast②diagnosing a virus at home③developing antiviral drugs④allowing us to intervene earlyA. ①②③B. ①②④C. ①③④D. ②③④9. As far as poorer countries areconcerned,which of the following is TRUE according to this passage?A. pandemic disease is more likely to begin in poorer countriesB. Working from home can work well in poorer countries.C. Health systems are sufficient to care for the infected in poorer countries.D. Virus will cross borders if poorer countries fail to contain it.10. Why is the Second World War mentioned in Para.8?A. The fight against the COVID-19 is similar to the Second World War.B. People are suffering just as they were in the Second World War.C. We should cooperate globally just as we did after the Second World War.D. Countries are fighting each other like in the Second World War.11. What is the tone of this passage?A. pessimisticB. optimisticC. neutralD. indifferentDTen years ago, I set out to examine luck. I wanted to know why some people were always in the right place at the right time, while others consistently experienced ill fortune. I placed advertisements in national newspapers asking for people who felt consistently lucky or unlucky. Hundreds of extraordinary men and women volunteered for my research. Over the years I have interviewed them, monitored their lives and had them take part in various experiments.In one of the experiments, I gave both lucky and unlucky people a newspaper, asking them to look through it and tell me how many photographs were inside. I had secretly placed a large message halfway through the newspaper, saying, “Tell the experimenter you have seen this and you will win $50.” This message took up half of the page and was written in type that was more than two inches high. It was staring everyone in the face, but the unlucky people tended to miss it and the lucky people tended to spot it.Unlucky people are generally more nervous than lucky people, and this anxiety affects their ability to notice the unexpected. As a result, they miss opportunities because they are too focused on looking for something else. They go to gatherings concentrating on finding their perfect partners and miss opportunities to make good friends. They look through newspapers determined to find certain types of job advertisements and miss other types of jobs.Lucky people are more relaxed and open, and therefore see what is there rather than just what they are looking for. My research eventually showed that lucky people are skilled at noticing opportunities, make lucky decisions by listening to their intuition (直觉), are open to new experiences, and adopt a never-say-die attitude that transforms bad luck into good luck.12. What’s the purpose of the author’s research?A. To discover what luck means to people.B. To find lucky people and unlucky people.C. To distinguish between good luck and bad luck.D. To figure out why people are always lucky or unlucky.13. Why did the unlucky people miss the message in the experiment?A. There was too much information to be read in detail.B. They were too focused on looking for photographs.C. It took too much time to go through newspapers.D. The words were too small to be noticed.14. What leads to lucky people’s good fortune?A. Their ability to spot opportunities.B. Their ability to become relaxed.C. Their ability to communicate.D. Their ability to make friends.15. What’s the key message of the last paragraph?A. What lucky people are looking for.B. How lucky people generate good luck.C. What lucky people can do with opportunities.D How lucky people transform bad luck into good luck.第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。

成都七中初中学校2020年期中单元测试一、选择题1．如图，给物体一个初速度后，物体沿粗糙斜面向上滑动。

在向上滑动的过程中，关于物体受到的力，下列说法正确的是（）A．受重力、沿斜面向上的冲力、斜面的支持力B．受重力、沿斜面向上的冲力、沿斜面向下的滑动摩擦力C．受重力、斜面的支持力、沿斜面向下的滑动摩擦力D．受重力、斜面的支持力、沿斜面向上的冲力、沿斜面向下的滑动摩擦力、沿斜面向下的下滑力2．如图所示，有3000个质量均为m的小球，将它们用长度相等的轻绳依次连接，再将其左端用细绳固定在天花板上，右端施加一水平力使全部小球静止．若连接天花板的细绳与水平方向的夹角为37°．则第1218个小球与1219个小球之间的轻绳与水平方向的夹角α的正切值等于（sin37°＝0.6，cos37°＝0.8）A．17814000B．12194000C．6092000D．89120003．关于力、重力和弹力，下列说法正确的是A．在画力的图示时，力的作用点可不画在受力物体上B．把一木块放在水平桌面上保持静止，木块对桌面的压力就是木块受的重力C．把一木块放在水平桌面上保持静止，木块对桌面的压力，是由于木块发生形变而产生的D．形状规则的任何物体的重心都在它的几何中心上4．如图所示，一个重200N的物体，在粗糙水平面上向右运动，物体和水平面间的动摩擦因数μ=0.1，同时物体还受到大小为10N、方向向左的水平力作用，则水平面对物体的摩擦力的大小和方向是A ．大小是10N ，方向向左B ．大小是20N ，方向向左C ．大小是20N ，方向向右D ．大小是10N ，方向向右5．如图所示，用水平力去推静止在水平地面上的大木箱， 没有推动。

关于木箱受到的推力和摩擦力，下列说法正确的是A ．推力和摩擦力大小相等B ．推力小于摩擦力C ．推力和摩擦力方向相同D ．推力大于摩擦力6．某同学绕操场一周跑了400m ，用时65s ，这两个物理量分别是A ．路程、时刻B ．位移、时刻C ．路程、时间间隔D ．位移、时间间隔 7．从静止开始做匀加速直线运动的物体，0～10s 内的位移是10m ，那么在10s ～20s 内的位移是（）A ．20mB ．30mC ．40mD ．60m8．如图所示，球A 在斜面上，被竖直挡板挡住而处于静止状态，关于球A 所受的弹力，以下说法正确的是 ( )A ．球A 仅受一个弹力作用，弹力的方向垂直斜面向上B ．球A 受两个弹力作用，一个水平向左，一个垂直斜面向下C ．球A 受两个弹力作用，一个水平向右，一个垂直斜面向上D ．球A 受三个弹力作用，一个水平向右，一个垂直斜面向上，一个竖直向下． 9．一物体在地面以速度为 v 向上竖直上抛，不计空气阻力，经过 t 时间到最高点，上升高度为 h ，则A ．物体通过前半程和后半程所用时间之比为 1：21 )B ．物体通过2h 处的速度为 2v C ．物体经过 2t时的速度为 2v D ．物体经过前 2t 和后 2t 的位移之比为 1:310．手机导航越来越多成为人们出行的必备工具，绍兴多风景名胜，某游客游完兰亭后驾车去东湖，他打开手机导航，搜索了驾车线路，线路显示走常规路线距离19.8km ，需用时27分钟，选择走距离较短则有17.4km，需用时30分钟，如果走高速优先则有22.3km，需用时29分钟，则下列判断正确的是（）A．走常规路线的19.8km指的是位移B．走“距离较短”说明路程最小C．选择走“距离较短”，则瞬时速率一定最小D．走“高速优先”，平均速度最大11．下列作直线运动的v-t图象中，表示质点作匀变速直线运动的是（）A．B．C．D．12．在电视连续剧《西游记》中，常常有孙悟空“腾云驾雾”的镜头，这通常是采用“背景拍摄法”：让“孙悟空”站在平台上，做着飞行的动作，在他的背后展现出蓝天和急速飘动的白.放云，同时加上烟雾效果；摄影师把人物动作和飘动的白云及下面的烟雾等一起摄入镜头.这时，观众所选的参考系是()映时，观众就感觉到“孙悟空”在“腾云驾雾”A．“孙悟空”B．平台C．飘动的白云D．烟雾13．小洪同学乘出租车从校门口出发，到火车站接到同学后当即随车回校．出租车票如图所示，则以下说法正确的是( )A．位移为16.2kmB．路程为0C．11：48指的是时间D．11：05指的是时刻14．如图为一个做直线运动物体的v-t图象，则A．0~3s物体做匀速直线运动B．3~6s物体做匀速直线运动C．2 s和4s时刻的速度方向相反D．第3s时刻物体速度方向发生改变5m/s，则自驾驶15．汽车以20m/s的速度在平直公路上行驶，急刹车时的加速度大小为2员急踩刹车开始，2s与5s时汽车的位移之比为（）A．5:4B．4:5C．3:4D．4:316．两物体都做匀变速直线运动，在给定的时间间隔t内（）A．加速度大的，其位移一定大B．初速度大的，其位移一定大C．末速度大的，其位移一定大D．平均速度大的，其位移一定大17．以下物理量中是矢量的有 ( )a.位移b.路程c.瞬时速度d.平均速度e.时间f.加速度g.速率A．只有acdfB．只有adfC．只有afgD．只有af18．如图，光滑斜劈A上表面水平，物体B叠放在A上面，斜面光滑，AB静止释放瞬间，B的受力图是（）A．B．C．D．19．（题文）重型自卸车利用液压装置使车厢缓慢倾斜到一定角度，车厢上的石块就会自动滑下，以下说法正确的是A．在石块下滑前后自卸车与石块整体的重心位置不变B．自卸车车厢倾角越大，石块与车厢的动摩擦因数越小C．自卸车车厢倾角越大，车厢与石块间的正压力减小D．石块开始下滑时，受到的摩擦力大于重力沿斜面方向的分力20．某航母跑道长200m飞机在航母上滑行的最大加速度为6m/s2，起飞需要的最低速度为50m/s．那么，飞机在滑行前，需要借助弹射系统获得的最小初速度为A．5m/s B．10m/s C．15m/s D．20m/s二、多选题21．如图甲所示，质量为m2的长木板静止在光滑的水平面上，其上静止一质量为m1的小滑块，现给木板施加一随时间均匀增大的水平力F，满足F=kt（k为常量，t代表时间），长木板的加速度a随时间t变化的关系如图乙所示。

2020-2021学年成都七中实验学校九年级上学期期中物理试卷一、单选题（本大题共17小题，共34.0分）1.下列关于热、热值和热机效率的描述，正确的是()A. 使燃料燃烧更充分，可以增大其热值B. 只要燃料充分燃烧，就可以提高热机效率C. 甲柴油机的效率比乙的效率高，燃烧质量相同的燃料甲柴油机将燃料燃烧放出的热量变成有用功的能量比乙大D. 铝的比热容大于铜，质量和初温相同的铜块和铝块放出相同热量后放在一起，热量由铜块传给铝块2.关于物体的内能，下列说法正确的是()A. 晶体熔化时，吸热、温度不变，内能不变B. 物体内能增加，一定要从外界吸收热量C. 温度为0℃的物体没有内能D. 在相同物态下，同一物体温度降低，它的内能会减少3.下列说法正确的是()A. 一瓶酒精用去一半，酒精的热值减小一半B. 煤的热值比干木柴的热值大，所以燃烧时煤放出的热量更多C. 内燃机的效率越高，它消耗的燃料就越少D. 热机效率越高，它将内能转化为机械能的比例越大4.下列关于电流和电压的说法，其中正确的是()A. 自由电荷的移动形成了电流B. 电荷定向移动的方向为电流方向C. 电路两端有电压，电路中就一定有电流D. 电路中有电流，电路两端就一定有电压5.如图为试电笔的结构及使用方法。

下列说法错误的是()A. 在两种使用试电笔的方法中，甲是错误的，乙是正确的B. 笔尖、电阻和氖管是导体，外壳、弹簧和笔卡是绝缘体C. 若氖管发光，说明人体成为了电流的通路D. 试电笔可以辨别火线和零线6.科研人员设计了一种可以节约用电的楼道灯电路。

用光敏材料制成“光控开关”——天黑闭合，天亮断开；用声敏材料制成“声控开关”——有人走动发声会闭合，无人走动会断开。

若将两种开关配合使用，就可以使楼道灯变得“聪明”。

则图中的“聪明”电路是()A. B.C. D.7.如下图中，右边的四幅电路图与左图所示实物图对应的是()A.B.C.D.8.小明同学使用电流表时，本应使用“−”和“0.6”接线柱，但误将“−”和“3”接线柱接入电路．这样做的结果将是()A. 电流表的指针转过的角度变小了B. 电流表的指针转过的角度变大了C. 电流表的指针不偏转D. 电流表的指针反向偏转9.导体棒a和b的材料与长度都相同，a比b的横截面积大，将它们接入电路中，如图所示，通过a、b电流分别为I a、I b，a、b两端电压分别为U a、U b，则下列说法正确的是()A. I a>I b、U a=U bB. I a<I b、U a=U bC. I a=I b、U a>U bD. I a=I b、U a<U b10.一定值电阻，两端加6V电压时，通过的电流是1A，当在其两端加3V电压时，则通过的电流和导体的电阻是()A. 0.5A6ΩB. 1A6ΩC. 0.5A3ΩD. 1A3Ω11.如图所示电源电压为12V且保持不变。

成都七中实验学校（初中部）2020年化学上册期中试题及答案一、选择题（培优题较难）1．根据图中提供的信息判断，下列说法正确的是A．③④属于同种元素B．②表示的元素在形成化合物时化合价为+1 价C．①③的化学性质相似D．硒元素的相对原子质量为 78.96 g2．在一密闭的容器中，一定质量的碳粉与过量的氧气在点燃的条件下充分反应,容器内各相关量与时间(从反应开始计时)的对应关系正确的是( )A．B．C．D．3．下列对实验现象的描述或实验操作正确的是A．红磷在空气中燃烧，产生大量白雾B．点燃或加热可燃性气体前，先检验其纯度C．10mL酒精与10mL蒸馏水混合，溶液的体积为20mLD．用高锰酸钾制取O2后，应先熄灭酒精灯再从水中取出导气管4．下列实验设计不能达到其对应实验目的的是( )A．测定空气里氧气的含量B．检查装置的气密性C．验证质量守恒定律D．证明CO2密度比空气的大5．石墨烯是一种革命性材料，具有优异的光学、电学和力学特性。

图为金刚石、石墨和石墨烯的结构模型图，图中小球代表碳原子。

下列说法正确的是( )①石墨烯是一种新型化合物②三种物质分别在足量的氧气中完全燃烧的产物相同③金刚石和石墨烯是组成相同但结构不同的两种物质④石墨烯有超强的导电性和导热性，说明石墨烯的化学性质和金属相似A．①④B．②③C．①③D．②③④6．2017年10月27日央视财经报道：王者归“铼”，中国发现超级金属铼，制造出航空发动机核心部件。

如图是铼在元素周期表中的相关信息，下列有关说法不正确的是（）A．铼原子的核内质子数为75 B．铼的相对原子质量为186.2gC．铼的元素符号是Re D．铼原子的核外电子数为757．已知：金属X在常温下能与空气中的氧气反应，而金属Y和Z不能；将Y 、Z分别投入稀盐酸中，Y溶解并产生气泡，Z无变化。

下列说法正确的是A．X氧化物的化学式只能表示为XO B．Y能将X从它的盐溶液中置换出来C．Z在自然界中只能以单质形式存在 D．三种金属的活动性顺序：X>Y>Z8．鉴别二氧化碳、氧气、空气三种气体，可选用的最佳方法是( )A．将气体分别通入水中B．将燃着的木条分别伸入气体中C．将带火星的木条分别伸入气体中D．将气体分别通入澄清石灰水中9．硼是作物生长必需的微量营养元素，硼元素的相关信息如图所示。

2020-2021成都七中实验学校（初中部）高一数学下期中模拟试卷(含答案)一、选择题1．水平放置的ABC V 的斜二测直观图如图所示，若112A C ＝，111A B C △的面积为22，则AB 的长为（ ）A 2B ．17C ．2D ．82．已知正四棱锥P ABCD -的所有顶点都在同一球面上，若球的半径为3，则该四棱锥的体积的最大值为（ ） A ．643B ．32C ．54D ．643．下列命题正确的是（ ） A ．经过三点确定一个平面B ．经过一条直线和一个点确定一个平面C ．两两相交且不共点的三条直线确定一个平面D ．四边形确定一个平面4．圆心在x +y =0上，且与x 轴交于点A （-3，0）和B （1，0）的圆的方程为（ ） A ．22(1)(1)5x y ++-= B ．22(1)(1)5x y -++= C ．22(1)(1)5x y -++=D ．22(1)(1)5x y ++-=5．<九章算术>中，将四个面都为直角三角形的三棱锥称之为鳖臑.若三棱锥P ABC -为鳖臑，PA ⊥平面,2,4ABC PA AB AC ===，三棱锥P ABC -的四个顶点都在球O 的球面上，则球O 的表面积为（ ） A ．8π B ．12π C ．20π D ．24π 6．已知直线20ax y a +-+=在两坐标轴上的截距相等，则实数(a = )A ．1B ．1-C ．2-或1D ．2或17．已知圆M ：2220x y y =++与直线l ：350ax y a +-+=，则圆心M 到直线l 的最大距离为（ ） A ．5B ．6C ．35D 418．长方体的三个相邻面的面积分别为2，3，6，则该长方体外接球的表面积为( ) A ．72π B ．56π C ．14π D ．64π9．设直线,a b 是空间中两条不同的直线，平面,αβ是空间中两个不同的平面，则下列说法正确的是（ ）A ．若a ∥α，b ∥α，则a ∥bB ．若a ∥b ，b ∥α，则a ∥αC．若a∥α，α∥β，则a∥βD．若α∥β，aα⊂，则a∥β10．一个几何体的三视图如图所示，则该几何体的表面积为（）A． B． C． D．11．某几何体的三视图如图所示（单位：cm），其俯视图为等边三角形，则该几何体的体积（单位：3cm）是（）A．43B．1033C．23D．83312．如图，网格纸上小正方形的边长为1，粗实（虚）线画出的是某多面体的三视图，则该多面体的体积为（）A．64B．643C．16D．163二、填空题13．已知平面α与正方体的12条棱所成角相等，设所成角为θ，则sinθ=______.14．在学习公理四“平行于同一条直线的两条直线平行”时，有同学进行类比，提出了下列命题：①平行于同一平面的两个不同平面互相平行；②平行于同一直线的两个不同平面互相平行；③垂直于同一直线的两个不同平面互相平行；④垂直于同一平面的两个不同平面互相平行；其中正确的有________15．已知三棱锥P ABC -中，侧面PAC ⊥底面ABC ，90BAC ∠=︒，4AB AC ==，23PA PC ==，则三棱锥P ABC -外接球的半径为______.16．若圆的方程为2223()(1)124k x y k +++=-，则当圆的面积最大时，圆心坐标和半径分别为 、 ．17．函数2291041y x x x =++-+的最小值为_________.18．如图：点P 在正方体1111ABCD A B C D -的面对角线1BC 上运动，则下列四个命题： ①三棱锥1A D PC -的体积不变； ②1A P ∥面1ACD ；③1DP BC ^； ④面1PDB ^面1ACD ．其中正确的命题的序号是__________.19．已知球的表面积为20π，球面上有A 、B 、C 三点．如果2AB AC ==，22BC =ABC 的距离为__________．20．已知直线1:1l y x =-上有两个点11(,)A x y 和22(,)B x y , 且12,x x 为一元二次方程2610x x -+=的两个根, 则过点,A B 且和直线2:1l x =-相切的圆的方程为______________.三、解答题21．在平面直角坐标系xOy 中，已知圆C 经过()0,2A ，()0,0O ，(),0D t （0t >）三点，M 是线段AD 上的动点，1l ，2l 是过点()10B ,且互相垂直的两条直线，其中1l 交y 轴于点E ，2l 交圆C 于P 、Q 两点. （1）若6t PQ ==，求直线2l 的方程； （2）若t 是使2AM BM ≤恒成立的最小正整数 ①求t 的值； ②求三角形EPQ 的面积的最小值．22．如图，在平面直角坐标系xoy 中，点(0,3)A ，直线:24=-l y x ，设圆C 的半径为1， 圆心在l 上.（1）若圆心C 也在直线1y x =-上，过点A 作圆C 的切线，求切线方程； （2）若圆C 上存在点M ，使2MA MO =，求圆心C 的横坐标a 的取值范围. 23．在三棱柱111ABC A B C -中，侧面11AA C C ⊥底面ABC ，112AA AC AC AB BC =====，且点O 为AC 中点.(1)证明：1A O ⊥平面ABC ； (2)求三棱锥1C ABC -的体积.24．（1）用符号表示下来语句，并画出同时满足这四个语句的一个几何图形： ①直线l 在平面α内； ②直线m 不在平面α内； ③直线m 与平面α交于点A ； ④直线l 不经过点A .（2）如图，在长方体1111ABCD A B C D -中，E 为棱1BB 的中点，F 为棱1CC 的三等分点，画出由1,,D E F 三点所确定的平面β与平面ABCD 的交线.(保留作图痕迹)25．已知圆()22:14C x y -+=内有一点1,12P ⎛⎫ ⎪⎝⎭，过点P 作直线l 交圆C 于,A B 两点． （1）当点P 为AB 中点时，求直线l 的方程； （2）当直线l 的倾斜角为45o 时，求弦AB 的长．26．如图，四棱锥P ABCD -中，AP ⊥平面1,//,,,2PCD AD BC AB BC AD E F ==分别为线段,AD PC 的中点.（1）求证：//AP 平面BEF ； （2）求证：平面BEF ⊥平面PAC【参考答案】***试卷处理标记，请不要删除一、选择题 1．B 解析：B 【解析】 【分析】依题意由111A B C △的面积为22114B C =，所以8BC =，2AC =，根据勾股定理即可求AB ． 【详解】依题意，因为111A B C △的面积为2所以11111sin 452AC B C ︒=⨯⋅=111222B C ⨯⨯⨯，解得114B C =， 所以8BC =，2AC =，又因为AC BC ⊥，由勾股定理得：AB ====故选B ． 【点睛】本题考查直观图还原几何图形，属于简单题. 利用斜二测画法作直观图，主要注意两点：一是与x 轴平行的线段仍然与x '轴平行且相等；二是与y 轴平行的线段仍然与y '轴平行且长度减半.2．A解析：A 【解析】 【分析】设底面ABCD 的边长为a ，四棱锥的高为h ，可得22122a h h =-，得出四棱锥的体积关于h 的函数()V h ，求出V 的极大值点，即可得到四棱锥的体积的最大值. 【详解】正四棱锥P ABCD -的所有顶点都在同一球面上，若球的半径为3，设底面ABCD 的边长为a ，四棱锥的高为h ，设正四棱锥的底面ABCD 的中心为1O .则2OA =,1PO ⊥ 平面ABCD .则22211OO O A OA +=,即()222332a h ⎛⎫+-= ⎪ ⎪⎝⎭，可得22122a h h =-. 则该四棱锥的体积为()221112233V a h h h h =⨯=- 令()()2122f h h hh =-，则()2246f h h h'=-当04h <<时，()0f h '>，()f h 单调递增. 当4h >时，()0f h '<，()f h 单调递减.所以当4h =时，该四棱锥的体积有最大值，最大值为：()216412424433⨯⨯-⨯⨯=. 故选：A【点睛】本题考查了四棱锥与球的组合体，求椎体的体积，关键是利用了导数求体积的最值．属于中档题．3．C解析：C 【解析】 【分析】根据确定一个平面的公理及推论即可选出. 【详解】A 选项，根据平面基本性质知，不共线的三点确定一个平面，故错误；B 选项，根据平面基本性质公理一的推论，直线和直线外一点确定一个平面，故错误；C 选项，根据公理一可知，不共线的三点确定一个平面，而两两相交且不共点的三条直线，在三个不共线的交点确定的唯一平面内，所以两两相交且不共点的三条直线确定一个平面，正确；选项D,空间四边形不能确定一个平面，故错误；综上知选C. 【点睛】本题主要考查了平面的基本性质公理一及其推论，属于中档题.4．A解析：A 【解析】 【分析】由题意得：圆心在直线x=-1上，又圆心在直线x+y=0上，故圆心M 的坐标为（-1，1），再由点点距得到半径。

成都七中实验学校2020学年度上期七年级半期考试英语试题考试时间：120分钟满分：150分越努力越幸运！A卷（共100分）第一部分听力测试（共30小题，计30分）一、听句子，根据所听到的内容选择正确答语。

每小题读两遍。

（共6小题，每小题1分；计6分）。

( )1.A. He is Jack. B.Yes, he is. C.He is fine.( )2.A. Hello! B.Goodbye! C.You're welcome.( )3.A. Yes, she is. B.They are keys. C.No, they aren't.( )4.A. OK. B. Come on. C.She is nice.( )5.A. Thanks. B.It's 528-637. C.It's a red phone.( )6.A. No, it isn't. B.It’s a nice room. C.They are my parents.二、听句子，选择与你听到的句子内容相符的图片。

每小题读两遍。

（共4小题，每小题1分；计4分）。

A B C D7. 8. 9. 10.三、听对话，根据对话内容及问题选择正确答案。

每小题念两遍。

（共10小题，每小题1分；计10分）。

( ) 11.A. A pen. B.A box. C.A book.( ) 12.A. Blue. B.Red. C.Black.( ) 13.A. Kate. B.Cindy. C.Helen.( ) 14.A. The girl's friend. B.The girl's cousin. C.The girl's brother.( ) 15.A. On the bed. B.On the table. C.Under the bed.( ) 16.A. Books. B.Cups. C.Keys.( ) 17.A. In her bag. B.On her desk. C.Everywhere.( ) 18.A. 489-621. B.358-147. C.358-471.( ) 19.A. Dick's father. B.Dick's mother. C.Dick's grandpa.( ) 20.A. The eraser. B.The notebook. C.The tape.四、听短文，根据短文内容选择正确答案。

2020-2021成都七中实验学校（初中部）高三数学上期中模拟试卷(含答案)一、选择题1．已知首项为正数的等差数列{}n a 的前n 项和为n S ，若1008a 和1009a 是方程2201720180x x --=的两根，则使0n S >成立的正整数n 的最大值是（ ）A ．1008B ．1009C ．2016D ．20172．数列{}n a 的前n 项和为21n S n n =++,()()1N*nn n b a n =-∈,则数列{}n b 的前50项和为（ ） A ．49B ．50C ．99D ．1003．已知关于x 的不等式()224300x ax a a -+<<的解集为()12,x x ，则1212a x x x x ++的最大值是（ ） A ．6 B ．23C ．43D ．433-4．下列函数中，y 的最小值为4的是（ ）A ．4y x x=+B ．222y x =+C ．4x x y e e -=+D ．4sin (0)sin y x x xπ=+<< 5．()()()3663a a a -+-≤≤的最大值为（ ）A ．9B ．92C ．3D ．3226．河南洛阳的龙门石窟是中国石刻艺术宝库之一，现为世界文化遗产，龙门石窟与莫高窟、云冈石窟、麦积山石窟并称中国四大石窟．现有一石窟的某处“浮雕像”共7层，每上层的数量是下层的2倍，总共有1016个“浮雕像”，这些“浮雕像”构成一幅优美的图案，若从最下层往上“浮雕像”的数量构成一个数列{}n a ，则()235log a a ⋅的值为（ ） A ．8B ．10C ．12D ．167．已知,x y 满足0404x y x y x -≥⎧⎪+-≥⎨⎪≤⎩，则3x y -的最小值为（ ）A ．4B ．8C ．12D ．168．在ABC ∆中，角,,A B C 的对边分别是,,a b c ， 2cos 22A b cc+=，则ABC ∆的形状为 A ．直角三角形 B ．等腰三角形或直角三角形 C ．等腰直角三角形D ．正三角形9．某校运动会开幕式上举行升旗仪式，旗杆正好处在坡度的看台的某一列的正前方，从这一列的第一排和最后一排测得旗杆顶部的仰角分别为和，第一排和最后一排的距离为56米（如图所示），旗杆底部与第一排在同一个水平面上．若国歌长度约为秒，要使国歌结束时国旗刚好升到旗杆顶部，升旗手升旗的速度应为()（米 /秒）A ．110B ．310 C ．12 D ．71010．在ABC V 中，角,,A B C 所对的边分别为,,a b c ，S 表示ABC V 的面积，若cos cos sin ,c B b C a A += )2223S b a c =+-，则B ∠=A ．90︒B ．60︒C ．45︒D ．30︒11．已知4213332,3,25a b c ===，则 A ．b a c << B ．a b c << C ．b c a <<D ．c a b <<12．若0,0x y >>，且211x y+=，227x y m m +>+恒成立，则实数m 的取值范围是（ ） A ．(8,1)-B ．(,8)(1,)-∞-⋃+∞C ．(,1)(8,)-∞-⋃+∞D ．(1,8)- 二、填空题13．在ABC ∆中，角,,A B C 的对边分别为,,a b c ，已知274sincos 222A B C +-=，且5,7a b c +==，则ab 为 ．14．等差数列{}n a 中，1351,14,a a a =+=其前n 项和100n S =，则n=＿＿15．已知数列{}n a 是递增的等比数列，14239,8a a a a +==，则数列{}n a 的前n 项和等于 .16．对一切实数x ，不等式2||10x a x ++≥恒成立，则实数a 的取值范围是_______ 17．某公司一年购买某种货物600吨，每次购买x 吨，运费为6万元/次，一年的总存储费用为4x 万元．要使一年的总运费与总存储费用之和最小，则x 的值是__________．18．已知无穷等比数列{}n a 的各项和为4，则首项1a 的取值范围是__________．19．已知三角形中，边上的高与边长相等，则的最大值是__________．20．如图所示，在平面四边形ABCD 中，2AB =，3BC =，AB AD ⊥，AC CD ⊥，3AD AC =，则AC =__________．三、解答题21．在ABC ∆中，内角、、A B C 的对边分别为a b c ，，，()2cos cos 0C a B b A c ++=.（Ⅰ）求角C 的大小； （Ⅱ）若22a b ==，，求()sin 2B C -的值.22．若数列{}n a 的前n 项和n S 满足*231?(N )n n S a n =-∈,等差数列{}n b 满足113233b a b S ==+，.(1)求数列{}n a 、{}n b 的通项公式; (2)设3nn nb c a =,求数列{}n c 的前n 项和为n T . 23．设函数1()|(0)f x x x a a a=++- （1）证明：()2f x ≥；（2）若(3)5f <，求a 的取值范围．24．设等差数列{}n a 的前n 项和为n S ，225+=-a S ，515=-S . （1）求数列{}n a 的通项公式； （2）求12231111+++⋯+n n a a a a a a . 25．已知在ABC V 中，角A ，B ，C 的对边分别为a ，b ，c ，且sin cos 0a B b A -=．（1）求角A 的大小：（2）若5a =2b =．求ABC V 的面积．26．已知数列{}n a 是等差数列，数列{}n b 是公比大于零的等比数列，且112a b ==,338a b ==.（1）求数列{}n a 和{}n b 的通项公式; （2）记n n b c a =，求数列{}n c 的前n 项和n S .【参考答案】***试卷处理标记，请不要删除一、选择题 1．C 解析：C 【解析】依题意知100810091008100920170,20180a a a a +=>=-<，Q 数列的首项为正数，()()1201610081009100810092016201620160,0,022a a a a a a S +⨯+⨯∴>∴==，()12017201710092017201702a a S a+⨯==⨯<，∴使0n S >成立的正整数n 的最大值是2016，故选C.2．A解析：A 【解析】试题分析：当1n =时，113a S ==；当2n ≥时，()()()22111112n n n a S S n n n n n -⎡⎤=-=++--+-+=⎣⎦,把1n =代入上式可得123a =≠.综上可得3,1{2,2n n a n n ==≥.所以3,1{2,12,n n b n n n n n -==-≠为奇数且为偶数.数列{}n b 的前50项和为()()503235749224650S =--+++++++++L L ()()24349252503224922++=--⋅+⋅=.故A 正确.考点：1求数列的通项公式;2数列求和问题.3．D解析：D 【解析】：不等式x 2-4ax +3a 2＜0（a ＜0）的解集为（x 1，x 2），根据韦达定理，可得：2123x x a =，x 1+x 2=4a ，那么：1212a x x x x ++=4a +13a． ∵a ＜0， ∴-（4a +13a ），即4a +13a ≤故1212a x x x x ++的最大值为． 故选D ．点睛：本题主要考查基本不等式，其难点主要在于利用三角形的一边及这条边上的高表示内接正方形的边长.在用基本不等式求最值时，应具备三个条件：一正二定三相等.①一正：关系式中，各项均为正数；②二定：关系式中，含变量的各项的和或积必须有一个为定值；③三相等：含变量的各项均相等，取得最值.4．C解析：C 【解析】 【分析】由基本不等式求最值的规则：“一正，二定，三相等”，对选项逐一验证即可. 【详解】选项A 错误，x Q 可能为负数，没有最小值；选项B错误，化简可得2y ⎫=，=，即21x =-，显然没有实数满足21x =-；选项D 错误，由基本不等式可得取等号的条件为sin 2x =， 但由三角函数的值域可知sin 1x ≤； 选项C 正确，由基本不等式可得当2x e =， 即ln 2x =时，4xxy e e -=+取最小值4，故选C.【点睛】本题主要考查利用基本不等式求最值，属于难题.利用基本不等式求最值时，一定要正确理解和掌握“一正，二定，三相等”的内涵：一正是，首先要判断参数是否为正；二定是，其次要看和或积是否为定值（和定积最大，积定和最小）；三相等是，最后一定要验证等号能否成立（主要注意两点，一是相等时参数否在定义域内，二是多次用≥或≤时等号能否同时成立）.5．B解析：B 【解析】【分析】根据369a a -++=是常数，可利用用均值不等式来求最大值. 【详解】 因为63a -≤≤， 所以30,60a a ->+> 由均值不等式可得：36922a a -++≤= 当且仅当36a a -=+，即32a =-时，等号成立， 故选B. 【点睛】本题主要考查了均值不等式，属于中档题.6．C解析：C 【解析】 【分析】数列{}n a ，是等比数列，公比为2，前7项和为1016，由此可求得首项1a ，得通项公式，从而得结论． 【详解】Q 最下层的“浮雕像”的数量为1a ，依题有：公比()717122,7,101612a q n S -====-，解得18a =，则()12*82217,n n n a n n N -+=⨯=≤≤∈，57352,2a a ∴==，从而()()571212352352222,log log 212a a a a ⋅=⨯=∴⋅==，故选C ．【点睛】本题考查等比数列的应用．数列应用题求解时，关键是根据题设抽象出数列的条件，然后利用数列的知识求解．7．A解析：A 【解析】 【分析】作出可行域，变形目标函数并平移直线3y x =，结合图象，可得最值． 【详解】作出x 、y 满足0404x y x y x -≥⎧⎪+-≥⎨⎪≤⎩所对应的可行域（如图ABC V ），变形目标函数可得3y x z =-，平移直线3y x =可知， 当直线经过点(2,2)A 时，截距z -取得最大值， 此时目标函数z 取得最小值3224⨯-=. 故选：A.【点睛】本题考查简单线性规划，准确作图是解决问题的关键，属中档题．8．A解析：A 【解析】 【分析】先根据二倍角公式化简，再根据正弦定理化角，最后根据角的关系判断选择. 【详解】 因为2cos22A b c c+=，所以1cosA 22b cc++=,()ccosA b,sinCcosA sinB sin A C ,sinAcosC 0===+=,因此cosC 0C 2π==，,选A.【点睛】本题考查二倍角公式以及正弦定理，考查基本分析转化能力，属基础题.9．B解析：B 【解析】试题分析： 如下图：由已知，在ABC ∆中，105,45,56ABC ACB BC ∠=∠==o o ,从而可得：30BAC ∠=o 由正弦定理，得：56sin 45AB =o 103AB ∴=那么在Rt ADB ∆中，60ABD o ∠=,3sin 6010315AD AB ∴===o ， 即旗杆高度为15米，由3155010÷=，知：升旗手升旗的速度应为310（米 /秒）. 故选B ．考点：解三角形在实际问题中的应用．10．D解析：D 【解析】 【分析】由正弦定理，两角和的正弦函数公式化简已知等式可得sin A ＝1，即A ＝900，由余弦定理、三角形面积公式可求角C ，从而得到B 的值． 【详解】由正弦定理及cos cos sin ,c B b C a A +=得2sin cos sin cos sin ,C B B C A +=()2sin sin sin 1C B A A ⇒+=⇒=,因为000180A <<，所以090A =；由余弦定理、三角形面积公式及)2223S b a c =+-，得13sin 2cos 2ab C ab C =, 整理得tan 3C =，又00090C <<,所以060C =,故030B =. 故选D 【点睛】本题考查正、余弦定理、两角和的正弦公式、三角形面积公式在解三角形中的综合应用，考查计算能力和转化思想，属于中档题．11．A解析：A 【解析】【分析】 【详解】因为422233332=4,3,5a b c ===，且幂函数23y x =在(0,)+∞ 上单调递增，所以b <a <c . 故选A.点睛：本题主要考查幂函数的单调性及比较大小问题，解答比较大小问题，常见思路有两个：一是判断出各个数值所在区间（一般是看三个区间()()(),0,0,1,1,-∞+∞ ）；二是利用函数的单调性直接解答；数值比较多的比大小问题也可以两种方法综合应用；三是借助于中间变量比较大小.12．A解析：A 【解析】 【分析】 将代数式21x y+与2x y +相乘，展开式利用基本不等式求出2x y +的最小值8，将问题转化为解不等式()2min 72m m x y +<+，解出即可. 【详解】由基本不等式得()21422448y x x y x y x y x y ⎛⎫+=++=++≥= ⎪⎝⎭， 当且仅当()4,0y xx y x y=>，即当2x y =时，等号成立，所以，2x y +的最小值为8. 由题意可得()2min 728m m x y +<+=，即2780m m +-<，解得81m -<<. 因此，实数m 的取值范围是(8,1)-，故选A. 【点睛】本题考查基本不等式的应用，考查不等式恒成立问题以及一元二次不等式的解法，对于不等式恒成立问题，常转化为最值来处理，考查计算能力，属于中等题．二、填空题13．6【解析】试题分析：即解得所以在中考点：1诱导公式余弦二倍角公式；2余弦定理解析：6 【解析】 试题分析：274sincos 222A B C +-=Q ，274sin cos 222C C π-∴-=，274cos cos 222C C ∴-=，()72cos 1cos 22C C ∴+-=，24cos 4cos 10C C ∴-+=，即()22cos 11C -=，解得1cos 2C =． 所以在ABC ∆中60C =o ．2222cos c a b ab C =+-Q ，()2222cos60c a b ab ab ∴=+--o，()223ca b ab ∴=+-，()22257633a b c ab +--∴===．考点：1诱导公式，余弦二倍角公式；2余弦定理．14．10【解析】【分析】【详解】故则故n=10解析：10 【解析】 【分析】 【详解】1351,14,a a a =+=故126d 14,2a d +=∴=，则()1n 21002n n n S -=+⨯=故n=1015．【解析】【分析】【详解】由题意解得或者而数列是递增的等比数列所以即所以因而数列的前项和故答案为考点：1等比数列的性质；2等比数列的前项和公式 解析：21n -【解析】 【分析】 【详解】由题意，14231498a a a a a a +=⎧⎨⋅=⋅=⎩，解得141,8a a ==或者148,1a a ==，而数列{}n a 是递增的等比数列，所以141,8a a ==，即3418a q a ==，所以2q =， 因而数列{}n a 的前n 项和1(1)1221112n nn n a q S q --===---，故答案为21n -. 考点：1.等比数列的性质；2.等比数列的前n 项和公式.16．－2+）【解析】【分析】根据题意分x=0与x≠0两种情况讨论①x=0时易得原不等式恒成立②x≠0时原式可变形为a≥-（|x|+）由基本不等式的性质易得a 的范围综合两种情况可得答案【详解】根据题意分两解析：[－2，+∞） 【解析】根据题意，分x=0与x≠0两种情况讨论，①x=0时，易得原不等式恒成立，②x≠0时，原式可变形为a≥-（|x|+ 1x），由基本不等式的性质，易得a 的范围，综合两种情况可得答案.【详解】根据题意，分两种情况讨论；①x=0时，原式为1≥0，恒成立，则a∈R；②x≠0时，原式可化为a|x|≥-（x 2+1），即a≥-（|x|+ 1x）, 又由|x|+1x ≥2，则-（|x|+1x）≤-2； 要使不等式x 2+a|x|+1≥0恒成立，需有a≥-2即可；综上可得，a 的取值范围是[-2，+∞）；故答案为[-2，+∞）．【点睛】本题考查不等式恒成立问题的解法，运用分类讨论和参数分离、基本不等式求最值是解题的关键，属于中档题．17．【解析】【详解】总费用为当且仅当即时等号成立故答案为30点睛:在利用基本不等式求最值时要特别注意拆拼凑等技巧使其满足基本不等式中正(即条件要求中字母为正数)定(不等式的另一边必须为定值)等(等号取得解析：30【解析】【详解】总费用为600900464()4240x x x x +⨯=+≥⨯=，当且仅当900x x=，即30x =时等号成立．故答案为30. 点睛:在利用基本不等式求最值时，要特别注意“拆、拼、凑”等技巧，使其满足基本不等式中“正”(即条件要求中字母为正数)、“定”(不等式的另一边必须为定值)、“等”(等号取得的条件)的条件才能应用，否则会出现错误．18．【解析】【分析】由无穷等比数列的各项和为4得且从而可得的范围【详解】由题意可得且且 故答案为【点睛】本题主要考查了等比数列的前n 项和而无穷等比数列的各项和是指当且时前n 项和的极限属于基础题解析：(0,4)(4,8)⋃【解析】【分析】由无穷等比数列{}n a 的各项和为4得,141a q=-,，||1q <且0q ≠,从而可得1a 的范围.由题意可得,14,||11a q q =<- ， 且0q ≠14(1)a q =-108a ∴<<且14a ≠故答案为(0,4)(4,8)⋃【点睛】本题主要考查了等比数列的前n 项和,而无穷等比数列的各项和是指当,||1q <且0q ≠时前 n 项和的极限，属于基础题.19．22【解析】试题分析：由题意得12bcsinA=12a2⇒bcsinA=a2因此ACAB+ABAC+BC2AB ⋅AC=bc+cb+a2bc=b2+c2+a2bc=a2+2bccosA+a2bc=2c解析：【解析】试题分析：由题意得，因此,从而所求最大值是考点：正余弦定理、面积公式【方法点睛】解三角形问题，多为边和角的求值问题，这就需要根据正、余弦定理结合已知条件灵活转化边和角之间的关系，从而达到解决问题的目的.其基本步骤是： 第一步：定条件即确定三角形中的已知和所求，在图形中标出来，然后确定转化的方向.第二步：定工具即根据条件和所求合理选择转化的工具，实施边角之间的互化.第三步：求结果.20．3【解析】分析：详解：设在直角中得所以在中由余弦定理由于所以即整理得解得点睛：在解有关三角形的题目时要有意识地考虑用哪个定理更合适或是两个定理都要用要抓住能够利用某个定理的信息一般地如果式子中含有角 解析：3【解析】分析：详解：设,3AC x AD x ==，在直角ACD ∆中，得CD =，所以sin CD CAD AD ∠==， 在ABC ∆中，由余弦定理2222cos2AB AC BC BAC AB AC +-∠==⋅ 由于2BAC CAD π∠+∠=，所以cos sin BAC CAD ∠=∠，23=23830x x --=，解得3x =. 点睛：在解有关三角形的题目时，要有意识地考虑用哪个定理更合适，或是两个定理都要用，要抓住能够利用某个定理的信息．一般地，如果式子中含有角的余弦或边的二次式时，要考虑用余弦定理；如果式子中含有角的正弦或边的一次式时，则考虑用正弦定理；以上特征都不明显时，则要考虑两个定理都有可能用到．三、解答题21．（Ⅰ）34C π=（Ⅱ）10- 【解析】【分析】（I ）利用正弦定理化简已知条件，求得cos C 的值，由此求得C 的大小.（II ）根据余弦定理求得c ，利用正弦定理求得sin B ，利用同角三角函数关系式求得cos B ，由二倍角公式求得sin 2,cos 2B B 的值，再由两角差的正弦公式求得()sin 2B C -的值.【详解】()sin cos sin cos sin 0C A B B A C ++=sin sin 0C C C +=，∴cos 2C =-，∵0C π<<，∴34C π=（Ⅱ）因为2a b ==，34C π=，由余弦定理得2222cos 242210c a b ab C ⎛=+-=+-⨯= ⎝⎭，∴c =由sin sin sin 5c b B C B =⇒=，因为B 为锐角，所以cos 5B =4sin 225B ==，223cos 2cos sin 5B B B =-=()43sin 2sin 2cos cos 2sin 525210B C B C B C ⎛-=-=⨯--⨯=- ⎝⎭【点睛】本小题主要考查利用正弦定理和余弦定理解三角形，考查同角三角函数的基本关系式，考查二倍角公式以及两角差的正弦公式，属于中档题.22．(1)13n n a -=，;(2)()223n nn T +=-. 【解析】【分析】（Ⅰ）由数列递推式求出a 1，在数列递推式中取n=n-1得另一递推式，作差后得到数列{a n }为等比数列，则数列{a n }的通项公式可求，再由b 1=3a 1，b 3=S 2+3求出数列{b n }的首项和公差，则{b n }的通项公式可求；（Ⅱ）把数列{a n }、{b n }的通项公式代入3n n n b c a =，直接由错位相减法求数列{c n }的前n 项和为T n ．【详解】（Ⅰ）当1n =时，111231,1S a a =-∴=当2n ≥时，()()112223131n n n n n a S S a a --=-=---，即13n n a a -= ∴数列{}n a 是以11a =为首项，3为公比的等比数列，13n n a -∴=.设{}n b 的公差为1132,33,3723,2d b a b S d d ===+==+=()31321n b n n ∴=+-⨯=+ , （Ⅱ）1232135721,33333n n n n n n c T ++==++++L ① 则234113572133333n n n T ++=++++L ②， 由①—②得，2312111211233333n n n n T ++⎛⎫=++++-⎪⎝⎭L 142433n n ++=+ ∴223n nn T +=-. 【点睛】 本题考查数列递推式，考查了等比关系的确定，训练了错位相减法求数列的前n 项和，是中档题．23．（1）详见解析；（2）15521(,22． 【解析】试题分析：本题第（1）问，可由绝对值不等式的几何意义得出min ()2f x =，从而得出结论；对第（2）问，由0a >去掉一个绝对值号，然后去掉另一个绝对值号，解出a 的取值范围.试题解析：（1）证明：由绝对值不等式的几何意义可知：min ()f x =12a a+≥，当且仅当1a =时，取等号，所以()2f x ≥. （2）因为(3)5f <，所以1335a a ++-<⇔1335a a ++-<⇔132a a -<-⇔ 11232a a a -<-<-a <<. 【易错点】在应用均值不等式时,注意等号成立的条件:一正二定三相等.考点：本小题主要考查不等式的证明、绝对值不等式的几何意义、绝对值不等式的解法、求参数范围等不等式知识，熟练基础知识是解答好本类题目的关键.24．（1）n a n =-；（2）1n n +. 【解析】【分析】(1)利用方程的思想，求出首项、公差即可得出通项公式；（2）根据数列{}n a 的通项公式表示出11n n a a +，利用裂项相消法即可求解. 【详解】（1）设等差数列{}n a 的公差为d ，由221325+=+=-a S a d ，5151015=+=-S a d ，即123+=-a d ，解得11a =-，1d =-，所以()11=---=-n a n n .（2）由n a n =-，所以11111(1)1+==-++n n a a n n n n ， 所以122311111111112231+⎛⎫⎛⎫⎛⎫++⋯+=-+-+⋯+- ⎪ ⎪ ⎪+⎝⎭⎝⎭⎝⎭n n a a a a a a n n 1111n n n =-=++. 【点睛】 利用裂项相消法求和的注意事项(1)抵消后并不一定只剩下第一项和最后一项，也有可能前面剩两项，后面也剩两项；(2)将通项裂项后，有时需要调整前面的系数，使裂开的两项之差和系数之积与原通项相等．25．（1）4A π=（2）4【解析】分析：（1）利用正弦定理化简已知等式，整理后根据sin 0B ≠求出sin cos 0A A -=，即可确定出A 的度数；（2）利用余弦定理列出关系式，把a ，b ，cosA 的值代入求出c 的值，再由b ，sinA 的值，利用三角形面积公式求出即可．详解：在ABC V 中，由正弦定理得sin sin sin cos 0A B B A -=．即()sin sin cos 0B A A -=，又角B 为三角形内角，sin 0B ≠，所以sin cos 0A A -=，即2sin 04A π⎛⎫-= ⎪⎝⎭， 又因为()0,A π∈，所以4A π=．（2）在ABC V 中，由余弦定理得：2222cos a b c bc A =+-⋅， 则2220442c c ⎛⎫=+-⋅ ⎪ ⎪⎝⎭． 即222160c --=．解得22c =-（舍）或42c =．所以12242422S =⨯⨯⨯=．· 点睛：解三角形问题，多为边和角的求值问题，这就需要根据正、余弦定理结合已知条件灵活转化边和角之间的关系，从而达到解决问题的目的.其基本步骤是：第一步：定条件，即确定三角形中的已知和所求，在图形中标出来，然后确定转化的方向. 第二步：定工具，即根据条件和所求合理选择转化的工具，实施边角之间的互化. 第三步：求结果.26．（1）31,2n n n a n b =-=；（2）1326n n +⨯--.【解析】试题分析：（1）设出等差数列{a n }的公差为d ，等比数列{b n }的公比为q ，且q>0．由已知列式求得等差数列的公差和等比数列的公比，代入等差数列和等比数列的通项公式得答案；（2）由c n =a bn 结合数列{a n }和{b n }的通项公式得到数列{c n }的通项公式，结合等比数列的前n 项和求得数列{c n }的前n 项和S n ．试题解析：（1）设等差数列的公差为，等比数列的公比为，且． 由，得，解得． 所以． 由，得，又，解得． 所以． （2）因为， 所以．。

2020年成都七中初中学校高三英语期中考试试题及参考答案第一部分阅读（共两节，满分40分）第一节（共15小题；每小题2分，满分30分）阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项APlan Your Visit to the British MuseumWe've made a few changes to ensure you can safely enjoy your visit:How to book tickets·Tickets for the permanent collection can only be hooked online in advance.·To book tickets for exhibitions, visit our exhibition pages. If you want to guarantee your visit to the permanent collection as well as the exhibition on your visit, you will need to book a separate ticket.·We are limiting numbers of people in the museum to ensure there is room for you to safely enjoy your visit. Everyone, including members and volunteers, will therefore need to book a free, timed ticket in advance.Important information about your ticket booking·You can book up to six tickets for people who live in the same family.·We will email yourticket to you, and you will need to show it either printed out or on your device (设备) when you arrive.·Please arrive at the time stated on your ticket-we cannot guarantee admission before or after it.Following the routeWe have created a new one-way route through the museum which will allow you to safely explore world cultures from the Mediterranean to the Middle East and from the Americas to Africa.·View a map of the route (Open in a new window).·Our audio guides (音频指南) are not available. However, youcan pay to download the audio introductions from iTunes (Open in a new window) or Google Play (Open in a new window) to each of the galleries and listen on your own device. Please remember to bring along your own headphones.1.Why does the museum offer timed tickets?A.To earn more money.B.To hire more volunteers.C.To save room for collections.D.To control the number of visitors.2.How can a visitor learn about the new route in advance?A.View an online map.B.Buy a new headphone.C.Buy audio guides from the museum.D.Download video introductions from iTunes.3.Where can you probably find the text?A.In a newspaper.B.In a magazine.C.On a website.D.In a report.BThe world's largest iceberg is floating toward South Georgia in the southernAtlantic Ocean. Scientists fear the iceberg could crash into the island and block major feeding areas for a large population of penguins and seals. If the iceberg hits the island, it could prevent the penguins and seals from reaching food supplies.The huge iceberg is named A68a. It broke away fromAntarctica's Larsen C Ice Shelf in 2017. Satellite images show the iceberg has remained in one piece. It is estimated to be about 150 kilometers long and 48 kilometers wide. It is traveling at one kilometer per hour and is on a path to hitSouth Georgiain around 30 days.This is the time of year when seals and penguins spend a lot of time caring for their young. The distance that parents have to travel to find food is crucial. That means they have to go a lot further or go around the iceberg to find sources of food.Ecologists say an iceberg crash would also disturb materials settled on the seabed, possibly polluting the surrounding seas. As the iceberg melts, it would also release large amounts of fresh water into the ocean. This could affect krill（磷虾）populations that are a major source of food for the island's wildlife. The iceberg could remain for up to 10 years and change the area's whole ecosystem. These are globally significant populations of these species. If these species fail in this particular area, then the numbers globally are going to go down quite dramatically.Professor Geraint Tarling, an ecologist at the British Antarctic Survey, said, "The breaking off of icebergs fromAntarcticais a natural process. But the process is changing with climate change. What we're seeing with models and some observations now is that this is happening at an increasing rate. And so, this might become more of a usual thing in the future."4. Why are the scientists worried about the coming iceberg crash?A. It will bring extremely cold weather.B. It will destroy the feeding areas of the animals.C. It will put wildlife on the island at risk of starving.D. It will prevent animals from moving to other places.5. What is paragraph 2 mainly about?A. The characteristic of the iceberg.B. The importance of the iceberg.C. The traveling speed of the iceberg.D. The forming process of the iceberg.6. What damage can an iceberg crash bring according to paragraph 4?A. Using up much fresh water.B. Polluting the surrounding farms.C. Changing the world's ecosystem.D. Affecting the number of certain species.7. How does Tarling think of the breaking off of icebergs fromAntarctica?A. It may slow down in the near future.B. It may become common in the future.C. It has a great influence on the climate.D. It helps scientists conduct a sea study.C"Sorry, but I don't agree with you..."This is usually followed by unbearable silence and angry tears. I've always found it difficult to disagree with someone, because I don't want to lose a friend. I've found it even harder to accept it when someone disagrees with me, because my ego（自尊心）ishurt.Before the other person gets a chance to explain why she disagrees with me, my usual response would be," If you aren't able to see my point of view, then what you think isn't worth my time or consideration, either." But now I've come to realize that when a friend disagrees with me, sometimes she is simply saying, "I don't agree with the way things are done." She still respects me as a person, and is only pointing out a better way to look at a matter. However, there may be times when my friend disagrees with me because I'm against the truth. That's when need to listen to what she says.I've learned that one way to help my friend is for me to be open and honest with the other to voice my thoughts and listen to the other carefully. While we can't control how a person will respond to our views, we must learn to disagree with our friends in love. We will never feel that we are better than the other person.And that will help us to be less emotional, and more objective in the way we express our opinions.In the same way, we can also stay open to feedback（反馈）from others,knowing that our friends may be correcting us in love.Good friendships build each other up, sometimes through disagreements and honest opinions. Though Idon't like being disagreed with, I'm starting to see the value of such disagreements.8. The author has found it difficult to disagree with someone because .A. he is a friendly personB. he usually hides his ideasC. he has no mind of his ownD. he wants to keep the friendship9. When a friend disagreed with him,the author used to .A. be unhappyB. argue with the friendC. break up with the friendD. explain things calmly10. The author will listen to a friend when .A. he is against the truthB. he doesn't tell the truthC. he is respected by a friendD. he does things in the wrong way11. What does the author mainly talk about in the text?A. How to keep friendship.B. How to avoid hurting a friend.C. How to express disagreements.D. How to deal with disagreements.DIf you believe in thermometers (温度计), you should believe in global warming. And if you believe in eating French fries with your hamburger, you should worry more about carbonemission.It won't happen overnight, but as the planet’s climate changes, the growth cycles of main crops will all be heavily affected. Here are three of the crops that might not beat the heat.The potato actually needs a great deal of beauty rest to develop properly. “They need a cool nighttime temperature in order to start growing the tuber, the part that we eat,” Nelson says.Temperature and altitude are two primary concerns in coffee growth, and farmers are stuck between a rock and a hard place. “We know that coffee grows in a certain temperature range,” Nelson says. “They've been moving up the mountains, but at some point you run out of mountains to move up.” Higher-grade strains of Arabica coffee in Central American regions are at particular risk due to the need for lower growing temperature, especially since diseases and pests are also becoming more of a factor as temperatures rise.Even if you're looking at the direct effects of temperature alone, rice is in trouble. “As nighttime temperatures go up, the rice is going to have a problem flowering and won't make as many seeds,” Nelson says. In addition to this direct heat consequence, rising sea levels will flood many rice paddies and destroy water salinity levels, while droughts will lower production, raise prices, and further shame westerners who are clumsy with chopsticks to be able to clear their plates once a new grain is adopted.12. What is the closest meaning to the underlined word “emission” in Paragraph 1?A. Mixture.B. Pollution.C. Giving off.D. Going down.13. What does the potatoes' development need according to Nelson?A. Cool temperature at night.B. Sudden rise of the temperature.C. Enough water and salt.D. Much sunshine and fresh air.14. The rice is difficult to flower,probably because ________.A. sea levels go up suddenlyB. many seeds can't be producedC. the temperature rises at nightD. both temperature and altitude rise15. What is the best title for the text?A. How Does Global Warming Affect WesternersB. How Does the Cool Temperature Affect RiceC. What Is the Real Reason For Crops’ GrowthD. Three Crops That Won't Survive Climate Changes第二节（共5小题；每小题2分，满分10分）阅读下面短文，从短文后的选项中选出可以填入空白处的最佳选项。

成都七中实验学校（初中部）2020年11月月考单元测试一、选择题1．两物体都做匀变速直线运动，在给定的时间间隔t 内（ ） A ．加速度大的，其位移一定大 B ．初速度大的，其位移一定大 C ．末速度大的，其位移一定大D ．平均速度大的，其位移一定大2．如图所示，在水平力F 的作用下，木块A 、B 保持静止．若木块A 与B 的接触面是水平的，且F≠0．则关于木块B 的受力个数可能是（ ）A ．3个或4个B ．3个或5个C ．4个或5个D ．4个或6个 3．原来作匀加速直线运动的物体，若其加速度逐渐减小到零，则物体的运动速度将（ ） A ．逐渐减小B ．逐渐增大C ．保持不变D ．先增大后减小4．水下潜水器某次海试活动中，完成任务后从海底竖直上浮，从上浮速度为v 时开始计时，此后匀减速上浮，经过时间t 上浮到海面，速度恰好为零，则蛟龙号在()00t t t <时刻距离海平面的深度为（ ）A ．2vtB ．0012t vt t ⎛⎫- ⎪⎝⎭C ．202t tvD ．()202v t t t- 5．某同学绕操场一周跑了400m ，用时65s ，这两个物理量分别是A ．路程、时刻B ．位移、时刻C ．路程、时间间隔D ．位移、时间间隔6．一辆汽车由车站开出，沿平直公路做初速度为零的匀变速直线运动，至第10 s 末开始刹车，再经5 s 便完全停下．设刹车过程汽车也做匀变速直线运动，那么加速和减速过程车的加速度大小之比是 A ．1∶2 B ．2∶1 C ．1∶4D ．4∶17．如图所示，斜面小车M 静止在光滑水平面上，一边紧贴墙壁．若再在斜面上加一物体m ，且M 、m 相对静止，此时小车受力个数为（ ）A ．3B ．4C ．5D ．68．下列说法中正确的是A ．平时我们问“现在什么时间？”里的“时间”是指时刻而不是指时间间隔B ．“坐地日行八万里”是以地球为参考系C ．研究短跑运动员的起跑姿势时，由于运动员是静止的，所以可以将运动员看做质点D ．对直线运动的某个过程，路程一定等于位移的大小9．如下图所示，两木块的质量分别为m 1和m 2，两轻质弹簧的劲度系数分别为k 1和k 2，上面木块压在上面弹簧上(但不拴接)，整个系统处于平衡状态．现缓慢向上提上面的木块，直到它刚离开上面的弹簧．在这个过程中，下面木块移动的距离为( )A ．11m g kB ．22m g kC ．12m g kD ．21m g k10．如图为一个做直线运动物体的v -t 图象，则A ．0~3s 物体做匀速直线运动B ．3~6s 物体做匀速直线运动C ．2 s 和4s 时刻的速度方向相反D ．第3s 时刻物体速度方向发生改变11．在一平直路段检测某品牌汽车的运动性能时，通过传感器发现汽车做直线运动的位移x 与时间t 的关系为x ＝5t ＋t 2(各物理量均采用国际单位制单位)，则该汽车 A ．第1 s 内的位移是5 m B ．前2 s 内的平均速度是6 m/s C ．任意相邻的1 s 内位移差都是1 m D ．任意1 s 内的速度增量都是2 m/s 12．以下物理量中是矢量的有 ( )a.位移b.路程c.瞬时速度d.平均速度e.时间f.加速度g.速率 A ．只有acdf B ．只有adf C ．只有afg D ．只有af13．下列说法表示同一时刻的是（ ） A ．第 3 s 末和第 4 s 初 B ．前 5s 内和第 5 s 内 C ．第 4 s 末和第 3 s 初D ．第 2 s 内和第 2s 末14．在地球物理学领域有一种测g 值的方法叫“差值法”，具体做法是：将真空长直管沿竖直方向放置，自其中O 点上抛一小球又落到O 点的时间为，在小球运动过程中经过比O 点高H的P点，小球离开P点到又回到P点所用的时间为.测得、和，可求得g等于A． B． C． D．15．如油画所示是伽利略研究自由落体运动时的情景，他设计并做了小球在斜面上运动的实验，关于这个实验的下列说法中不符合．．．史实的是（）A．伽利略以实验来检验速度与时间成正比的猜想是否真实B．伽利略让小球沿阻力很小的斜面滚下是为了“冲淡”重力的影响C．伽利略通过实验发现小球沿斜面滚下的运动是匀加速直线运动D．伽利略用实验而不是外推的方法得到斜面倾角增大到90 小球仍然会保持匀加速运动16．（题文）重型自卸车利用液压装置使车厢缓慢倾斜到一定角度，车厢上的石块就会自动滑下，以下说法正确的是A．在石块下滑前后自卸车与石块整体的重心位置不变B．自卸车车厢倾角越大，石块与车厢的动摩擦因数越小C．自卸车车厢倾角越大，车厢与石块间的正压力减小D．石块开始下滑时，受到的摩擦力大于重力沿斜面方向的分力17．汽车以10 m／s的速度在马路上匀速行驶，驾驶员发现正前方15 m处的斑马线上有行人，于是刹车礼让，汽车恰好停在斑马线前。