重庆市第八中学2020—2021学年九年级上学期期末英语试卷

重庆市第八中学2020-2021学年八年级（下）期末考试物理试题一、单选题1．下列物理量中最接近事实的是（）A．中学生体考跳绳时的功率约5W B．中学生漂浮在水中时浮力约60NC．中学生双脚站立时对地压强约1×103Pa D．中学生爬一层楼克服重力做功约1800J2．下列说法正确的是（）A．压力与重力总是大小相等B．接触面积越大，压强一定越小C．压力越大，压强一定越大D．压强是反映压力作用效果的物理量3．关于功、功率、机械效率的说法正确的是（）A．机械效率可以大于1B．功率越大，做功越快C．机械效率越大，功率越大D．有用功越多，机械效率越大4．下列理解正确的是（）A．水中的静止物体，浮力一定等于重力B．物体体积越大，所受浮力越大C．同一密度计漂浮在不同液体中时浮力相等D．物体密度越大，所受浮力越大5．如图所示，与大气压强有关的是（）A．用真空压缩袋收纳衣物B．医生用针筒注射新冠疫苗C．深海潜水员要穿特制的抗压潜水服D．削平的铅块相互挤压后“粘”在一起悬挂重物6．图中没有利用连通器的特点来工作的是（）A．红酒分酒器B．锅炉水位计C．船闸D．盆景自动供水器7．下列说法正确的是（）A．蓬松的棉被容易被压扁，说明分子间有空隙B．食堂糕点房香气扑鼻，说明分子在不停地做无规则运动C．固体很难被压缩，说明固体分子间只存在引力不存在斥力D．银河系、地球、原子核、分子是按照从大到小的尺度来排序8．如图所示，下列属于费力杠杆的是（）A．用铁锤撬钉子B．用船桨划船C．用定滑轮提钩码D．电工钳9．海上舰艇护航编队在距离较近时，通常采用“前后”队形而非“左右并排”队形进行护航，下列现象中与其原理相同的是（）A．帕斯卡裂桶实验B．高原上用普通锅不易煮熟米饭C．骆驼的宽大脚掌使其不易陷入流沙D．列车进站时乘客应在黄线区域外候车10．如图所示的四个实例中，为了增大压强的是（）A．篆刻刀磨得很锋利B．铁轨下面要铺枕木C．挖掘机装有宽大的履带D．书包肩带越宽使用感越舒适11．如图所示为小田同学做挺举时的动作过程图，下列说法不正确的是（）A．在准备发力过程中他对杠铃做了功B．从上拉到上挺过程中他对杠铃做了功C．从上挺到站立过程中他对杠铃做了功D．在站立稳定过程中他没有对杠铃做功12．如图所示，有一质量不计的轻质木板，木板上放有一个可连续改变重力的物块，木板左端可绕固定点O转动，右端用竖直向上的拉力F拉住使其始终在水平位置保持平衡。

重庆市2020-2021学年上学期九年级英语期中试卷分类汇编完成句子重庆市巴南区2021届九年级上学期期中考试英语试题VII. 完成句子。

（每空1分, 共10 分）根据所给提示, 完成句子。

每空一词, 含缩略词。

69. This shop opened three days ago. （改为否定句）This shop ____________ _____________three days ago.70. They have worked in the factory for10 years. （对划线部分提问）__________ ____________ have they worked in the factory?71. Lily works hard at math and Lucy works hard, too. （改为同义句）___________ Lily _____________Lucy work hard at math.72. 我们家乡发生了巨大变化。

（完成译句）Great changes have ___________ _______________in our hometown.73. 当你离开教室的时候, 应该随手关灯。

（完成译句）You ought to ____________ _______________the lights when you leave the classroom答案：69. didn’t open 70. How long 71. Both and 72. taken place 73. turn off2020年重庆市南开中学九年级上学期英语期中试卷VIII. 完成句子。

（每空0. 5分, 共5 分）根据所给提示, 完成句子。

每空一词, 含缩略词。

79. They used to play basketball on weekends. （改为否定句）They __________ _____________ to play basketball on weekends.80. It's 2 hours' bus ride from Chonging to Chengdu. （对画线部分提问）____________ ___________is it from Chongqing to Chengdu?81. He didn't pass the test. （改为同义句）He ___________ ____________ pass the test.82. 直到他有一天长大了, 他才会意识到父母的艰辛。

2021—2022学年上学期期末九年级测试英语试题卷（时间：60分钟满分：100分）一、阅读理解（20小题，每小题2分，共40分）阅读下面的语言材料，然后按要求做题。

A根据材料内容选择最佳答案。

1. V olunteers need to work for _____to clean up Live Oak.A.2 hoursB.2.5 hoursC.3 hoursD.3.5 hours2. To volunteer for FISH, you need to _________.A. arrive there before 8:30 amB. drive your own carC. bring a pair of glovesD. volunteer at least twice a week3. Judy wants to help look after dogs. She should call ________.A.630-4862B.309-3022C.832-3054D.406-20664. V olunteers can have free lunch _________.A. on Live Oak Clean-up DayB. in FISHC. in Rescue MeD. at Spring Book Fair5. V olunteers at Spring Book Fair need to do the following EXCEPT ________.A. keeping the books clean and tidyB. saying hello to people at the doorC. giving advice to shoppers on booksD. getting a book written by the organizerBWhen I was a kid, my brothers, sisters and I used to have ice cream for dessert. Every day, we would choose which ice cream flavor to have. Then we would happily wolf down our ice cream as fast as we could.Once when I was probably about 10 or 11, our grandpa came to visit. Grandpa always had a different view on things. At that time, my sister and I were making bets(打赌) on who could finish our own ice cream first. With a smile, Grandpa said, “Why would you want to finish first? If you eat slowly, it will last longer. You should have a competition to see who can finish last.” Even now, I always try to taste my ice cream, but of course this is about more than just dessert.Too often, kids want to scramble(争夺) for more, whether it’s more ice cream, more toys, or more friends. This habit persists(持续) into our adult years. We never develop the skill of treasuring(珍重) what we have. If we learn to recognize this pattern and change it, we will have a happier life.What my grandpa taught me that day was really that if you take the chance to enjoy what’s in front of you, the pleasure will last longer. It’s a lesson that, I think, has made my adult life happier as well. These days, when I want something, I wait as long asI can before I allow myself to have it. Then, when I finally get it, I make sure to treasure it as long as possible. Because I know that no matter what it is, it will be gone all too soon.根据材料内容选择最佳答案。

重庆⼋中2020—2021学年度（上）半期考试⾼⼀年级英语试题第⼀部分听⼒（共两节，满分30分）做题时，先将答案标在试卷上。

录⾳内容结束后，你将有两分钟的时间将试卷上的答案转涂到答题卡上。

第⼀节听下⾯5段对话。

每段对话后有⼀个⼩题，从题中所给的A、B、C三个选项中选出最佳选项。

听完每段对话后，你都有10秒钟的时间来回答有关⼩题和阅读下⼀⼩题。

每段对话仅读⼀遍。

1.In which subject did Mary get an A?A.Social studies.B.Science.C.P.E.2.What is the purpose of the man’s call?A.To make an appointment.B.To cancel an appointment.C.To confirm an appointment.3.Where does the conversation take place?A.At home.B.In a hospital.C.At a furniture store.4.What does the man want to cut out of paper?A.A bird.B.A fish.C.A monkey.5.What are the speakers mainly talking about?A.The woman’s age.B.The woman’s weight.C.The woman’s eating habits.第⼆节听下⾯5段对话或独⽩。

每段对话或独⽩后有⼏个⼩题，从题中所给的A、B、C三个选项中选出最佳选项，并标在试卷的相应位置。

听每段对话或独⽩前，你将有时间阅读各个⼩题，每⼩题5秒钟；听完后，各⼩题将给出5秒钟的作答时间。

每段对话或独⽩读两遍。

听第6段材料，回答第6、7题。

6.What does the man need?A.Shampoo.B.A toothbrush.C.Soap.7.How does the man probably feel at the end of the conversation?A.Excited.B.Amused.C.Upset.听第7段材料，回答第8⾄10题。

重庆市第八中学2020-2021学年八年级上学期第一次月考英语试题学校:___________姓名：___________班级：___________考号：___________一、未知1．—What did you buy ________ yesterday morning?—I bought ________ umbrella.A．on; a B．不填;a C．on; an D．不填; an 2．Last Sunday we didn't go out ________ the rain.A．because of B．because C．in front of D．before 3．The mountain is too high ________ this seventy-year-old man.A．as B．for C．by D．about4．He ________ gets up at six o'clock, but today he got up at six thirty.A．hardly B．ever C．never D．often 5．Your house is bigger than ________.A．he B．him C．he's D．his6．________ my father didn't feel well, he worked hard.A．Although B．Because C．So D．But 7．—Do Bob and Henry like playing computer games?—Yes, ________ of them does.A．no B．all C．every D．each 8．—The story was really touching.—Yeah. It made me ________ when I read it.A．cry B．relax C．sleep D．laugh 9．Mike made a decision ________ the museum this Sunday.A．visit B．visits C．visiting D．to visit 10．In some ________, Tom looks like his grandpa.A．ideas B．ways C．notes D．words 11．Sam liked ________ of the two toys.A．the expensive one B．one most expensiveC．a least expensive D．the most expensive of them 12．Larry always ________ me in tennis, but I do better in basketball than him.A．wins B．plans C．beats D．worries 13．—You look younger and more beautiful in this shirt.—________.A．No, I'm not B．I think soC．You' re welcome D．Thank you for saying soPeter, a thirteen-year-old boy, was ill in hospital. Five days ago, while he was________ basketball, he hurt his head. The doctor thought that he might ________ get well. "He seems to give up hope. So medicines alone（单独的）won't ________. He says he wants to meet LeBron James, the famous basketball player," said the doctor.It was not ________ to meet LeBron James. The next day, Peter's father ________ to tell LeBron James the story of his son on the phone. Twenty-four hours later, LeBron James came to the ________ room. Young Peter could ________ believe his own eyes!The great basketball player sat down and said, "Now, listen, kid. You have to get well soon.I bring you a new American League basketball ________ you must start praticing it."For Peter, it was the beginning of his new life. ________ the doctor's surprise, the boy became ________ a few weeks later. He was able to recover（康复）all because of the help of LeBron James.14．A．looking B．playing C．taking D．sitting 15．A．never B．ever C．always D．certainly 16．A．fit B．work C．make D．do 17．A．easy B．lucky C．difficult D．successful 18．A．refused B．tried C．forget D．left 19．A．living B．hospital C．study D．rest 20．A．really B．mostly C．hardly D．nearly 21．A．though B．because C．or D．so22．A．In B．To C．At D．For 23．A．tired B．sad C．healthy D．weakCome to join us!24．When can you learn painting and swimming?A．On Monday and Friday. B．On Tuesday and Saturday.C．On Wednesday and Friday. D．On Friday and Saturday.25．What will you learn from Office 2010 on Wednesday?A．How to use cameras. B．How to paint.C．How to improve English. D．How to use the software.26．Which class is only for children aged 4-10?A．Painting. B．English. C．Photography. D．Office 2010.Fifteen years ago, I began to work as a reporter. The job was sometimes difficult, but for most of the time it was amazing because it taught me many unforgettable lessons.In India, I visited a city. There were many homeless children living in the street. But a kind-hearted Indian lady called Rosa opened a home for them. She looked after about two hundred kids, fed them, taught them and gave them hope.Another time, I was in Japan after a terrible earthquake. I met a lady. Her house fell down. Her son was missing and many people thought it was impossible to find him. But the lady did not give up hope. She kept moving heavy brisk（砖块）for four days by herself. She did not stop until she found her son. He was still alive!Then in China, I met a young boy with a serious illness. He had to have twenty operations in hospital. But when I met him, he was still smiling!Now I always remember the courage（勇气）of those people when I meet difficulties in my life.27．How many countries are mentioned（被提到）in the passage?A．One. B．Two. C．Three. D．Four. 28．Who was kind to open a home for homeless children?A．An Indian woman. B．A Japanese lady.C．A Chinese boy. D．The writer himself.29．Which of the following is TRUE?A．The writer's job is always easy and exciting.B．The Japanese lady found her son without others' help.C．The Chinese boy gave up hope because he was badly ill.D．The Indian woman looked after two thousand children.30．What's the main（主要的）idea of the passage?A．Children always need help from others.B．A reporter usually meets something wonderful.C．Courage and hope are very important.D．Some women or ladies like to help young people.Yellowstone National Park is one of the wildest places in the United States. But a few years ago, something very important was missing: wolves! To make things right, the US government（政府）decided to bring wolves back to Yellowstone, and they hope that the coming of wolves would help to stop the number of some animals from growing.The plan started in 1995, when scientists caught 14 wolves in Canada. Then they took the wolves to Yellowstone and put them into big outdoor cages（笼子）. As soon as the wolves got used to（习惯）their environment, the scientists let them walk freely in the wild.It seemed that the wolves were quickly making themselves right at home. In a few hours of leaving their cages, the wolves made their first kill. It was an elk—a kind of huge deer and their favorite prey in Canada. Elk lived in Yellowstone for many years without wolves, so their groups become bigger and stronger. But from the time the wolves were free, the wolves would help to stop the number of elk under control.Life was good for the wolves. Plenty of food meant they could have more babies. During the first year, there were 9 little baby wolves. At the same time, scientists caught 17 more big wolves in Canada and put them into the park again. In the spring of 1997, nine different kinds of wolf groups had 67 babies.Scientists thought they had to catch and bring more wolves to the park. However, with thewolf number growing so quickly, they decide that this is no more necessary.31．Why did the US government decide to bring wolves back to Yellowstone? A．Because wolves could make more visitors visit the park.B．Because wolves would help to stop the number of some animals from growing. C．Because wolves offered more food to other animals.D．Because wolves could keep many animals in the park safe.32．How many baby wolves were born in Yellowstone National Park in the first year? A．17 B．9 C．67 D．14 33．According to（根据）the last paragraph, what will the scientists do next?A．Catch more wolves in other countries.B．Stop bringing wolves to the park.C．Kill some wolves for other animals.D．Feed more elk in the park.34．Why did the writer write the passage?A．To encourage us to keep wolves safe.B．To explain why people are afraid of wolves.C．To tell about a successful decision about animals.D．To show the excitement of wolves coming back.Have you ever thought about going to the most famous universities in the world like Cambridge and Oxford University in England or Harvard and Yale University in America? It is very good and also difficult for college students to study in these universities, because most of them are always independent enough to pay for their education by themselves. Without the help of their parents, how can college students pay for the high price of tuition（学费）? The story about two students from Cambridge may give us a creative example.These 22-year-old young British men, Ross Harper and Moss Moyse from Cambridge, set up a website on which they sold their faces for advertisements（广告）. Their idea, called Buy My Face, is to rent（出租）their faces to companies every day. The companies paint theiradvertisement on their faces. "It's our unconventional way to raise enough money to pay for our college. No one else came up with such a creative idea as we did." they said. So far, they have made ￡47,000.The goal of the website isn't only to get people to look at the advertisements that are painted on their faces. Harper and Moyse also paint advertisements on their faces to advertise themselves. They started on January 1st 2017. The first advertisement went for ￡1 a day. But now the price has moved up to ￡400 a day. However, they know that their success won't be long-lived. And they plan to stop once they've made the money they need. "We don't know how long it will last, but you can have some fun going through our website". They have a lot of nice pictures on the website.35．According to the passage, if students study in those famous universities ________. A．most of them will live an easy and happy lifeB．most of them will have to get a full-time jobC．most of them will ask their parents for much moneyD．most of them will live a difficult but independent life36．Ross Harper and Moss Moyse ________.A．are young American men from CambridgeB．sell many students faces for advertisementsC．know that their success won't last foreverD．only paint their faces to advertise themselves37．The meaning of the word "unconventional" in the passage is close to ________. A．easy and common B．different and interestingC．difficult and strange D．traditional and tiring38．The best title of the passage may be" ________ ".A．Buy My Face B．Two College Students in Cambridge C．Expensive Ads D．How to Live Happily in the UniversityJust like any relationship, best friendships depend on trust, promise, respect and interests. When any of these elements（要素）is missing, the friendship will be hard to go on. If the trust is totally broken, you may not be able to forgive him/her.Sometimes a friendship ends because either you or your friend gets tired of putting the heart into it. This can happen when one of you finds a new friend or even a new hobby thattakes up much time. Or, perhaps you find the relationship is always going in an unhealthy way and you want some distance（距离）. Other times, you simply change and want to leave each other. Sure, it seems sad at the time, but it's completely normal.Not all friendships are meant to last forever. So, what should you do if something like this happens' to you? Read on for some friendly advice.Whatever the reason you're breaking up with your best friend is, always remember that he/she was once super important to you. Take the time to sit down and tell him/her what's going on and why. Don't send him/her an unpleasant e-mail. Don't start ignoring him/her though you're busy with your new hobby. In fact, maybe he/she has known there's a problem and would be willing to have a heart-to-heart chat. If you're not sure about wanting an end forever, you could suggest you two take a break from each other. If, after a while, you realize why you became the best friends in the beginning, you can try getting back to your former behaviors.Whatever you do, be honest about your feelings while having respect for his/hers. And if you both agree the Best Forever Friend thing is over, make sure not to be enemies. 39．According to the passage, what may end a friendship?A．Competing with each other for the same thingB．Living too far away from each other.C．Realizing it's hard to understand each other.D．Spending too much time on your new hobby40．The underlined word in the 4th paragraph probably means ________.A．忽视B．原谅C．理解D．误解41．What can be the best title for this passage?A．What is friendship?B．How to make friends?C．What to do when friendship is in trouble?D．How to find a real friend?42．If we put the passage into several parts, which of the following is the best?（①＝Par.（自然段）1 ②＝Para.2 ③＝Para.3 ④＝Para.4 ⑤＝Para.5）A．①②; ③④⑤B．①②; ③④; ⑤C．①; ②③④; ⑤D．①②③; ④⑤43．I love reading books in our library because the seats there are ________（comfort）44．You can more ________（cheap）buy iphones in that store.45．She is one of the most successful ________（win）in America's Got Talent.46．I think this restaurant is the ________（bad）in our city. I don't want to go there again. 47．There are a lot of after-class ________（activity）in our school.48．James put the tickets on the table.（改为否定句）James ________ ________ the tickets on the table.49．My apple is not so big as yours.（同义句）Your apple is ________ ________ mine.50．I like drinking tea. My mother likes drinking tea.（合并句子）My mother ________ I ________ like drinking tea.51．Ted is the smartest of all the boys in his class.Ted is smarter than ________ ________ classmates in his class.52．Ming好像是在生他哥哥的气。

重庆市2020-2021学年上学期九年级英语期中试卷分类汇编完形填空重庆市巴南区2021届九年级上学期期中考试英语试题II. 完形填空。

（每小题1. 5 分, 共15分）根据短文内容, 从A、B、C、D 四个选项中选出一个能填入相应空格内的最佳答案, 并把答题卡上对应题目的答案标号涂黑。

Do you know something about the usage of computers? People like scientists, teachers, writers and even students use computers to do nearly _31 work. But more than 30 years ago,_32_ couldn’t do much. They were very big and expensive. Very _33_people were interested in them and how to use them. Today computers are smaller and _34__. Since they are useful, many people like to use them.Computers _35__very important because they can work _36_ than people and make fewer mistakes. Computers can _37_people do a lot of work. Writers use computers to write; teachers use them to teach; students use them to study. Computers can also remember what you put _38_ them. Computers are very _39_. They are our good friends. Do you _40 Computer?Only we use computers correctly, can we get knowledge as much as possible.31. A. all kinds of B. many C. very much D. much32. A. teachers B. computers C. students D. houses33. A. few B. a few C. little D. a little34. A. cheaper B. cheap C. more expensive D. expensive35. A. is becoming B. becomes C. have become D. became36. A. quickly B. quick C. faster D. fast37. A. answer B. tell C. ask D. help38. A. on B. to C. up D. into39. A. useful B. careful C. beautiful D. skillful40. A. lend B. pay C. own D. borrow答案：31-35 ABAAC 36-40 CDDAC2020年重庆市南开中学九年级上学期英语期中试卷II. 完形填空。

2020-2021学年上学期九年级期末质量检测英语试卷（试卷满分：150 分考试时间：120 分钟）考生注意：本试卷分为两大部分,第一部分(1-70小题)为选择题,请考生将答案用2B铅笔填涂在答题卡上；第二部分为非选择题,请考生将答案用0.5毫米的黑色签字笔书写在答题卡上。

第一部分（选择题）I. 听力理解（共三节，20 小题，每小题1.5 分，满分30 分）第一节听句子听下面五个句子，从每小题所给的三幅图中选出与句子内容相符的选项（每个句子读两遍）第二节：听对话听下面七段对话，从每小题所给的A、B、C 三个选项中选出正确答案（每段对话读两遍）听第一段对话，回答第6小题。

6. What are the toy tigers made of?A. Wood.B.Clay.C. Paper.听第2段对话,回答第7小题。

7. How was the man advised to get to the train station?A. By subway.B. By bus.C. By taxi.听第3段对话,回答第8小题。

8. Which is the earliest invention?A. Hamburgers.B. Cola.C. Potato chips.听第4段对话,回答第9小题。

9. What arc the speakers doing?A. Doing some shopping.B. Preparing for a party.C. Having a picnic.听第5段对话,回答第10、11小题。

10. What can the model do?A. Run in the sea.B. Fly in the air.C. Climb up the wall.11. What does the girl think of it?A. She can't stand it.B. She doesn't mind it.C. She likes it.听第6段对话,回答第12、13小题12. When are they leaving for the airport?A.t8:15.B.At10:15.C.At12:15.13. What has the woman already done for the trip?A. Got the guidebook.B. Packed the clothes.C. Bought some gifts.听第7段对话,回答第14、15小题。

I．听力测试略II.单项选择重庆八中初2019 级九年级（上）第一次月考英语试题第I 卷1.I watched exciting movie called Toy Story. And movie made me fall in love with English.A. a; theB. an; theC. a; /D. an;/2.I don’t know he’ll come. I will let you know he comes.A. if; whetherB. whether; whetherC. if; ifD. whether; that3.Why not your teacher for help when you can’t finish it by yourself?A. ask; writeB. to ask; writingC. ask; writingD. asking; write4.I can’t hear what you said clearly, so please speak in a voice.A. louderB. more loudlyC. more aloudD. more loud5.She was a wonderful teacher. Everyone agreed it would be hard to find like her.A.the otherB. the othersC. anotherD. other6.— Look at the photo I took in Dali, Yunnan Province. the Dai people were having!— Wow! They were celebrating the Water Festival.A. What funB. How funC. What a funD. How a fun7.Peter out the quilt on the floor and down to have a rest.A. lay; laidB. laid; layC. laid; liedD. lied; lay8.—The doctor told me not to eat too much, but I find it difficult.—The doctor is right. you eat, you will be.A. The less; the healthierB. The less; the more healthierC The more; the healthier D. The more; the more healthier9.I found difficult English movies because I couldn’t understand what they said.A. It’s; to watchB. it; watchingC. it was; watchingD. it; to watch10.English is so important these days. I need some on how to learn English well.11.His parents expect be a successful writer when he grows up.A.he toB. he canC. him canD. his to12.Lei Feng for many years, but he still lives in the hearts of Chinese people.A.diedB. was dyingC. has been diedD. has been dead13.When you meet new words, why not in a dictionary?A.look up themB. look them upC. look them outD. look at them14.—Excuse me, could you tell me ?—Sorry, I don’t know. You can go to the information desk.A. that there was a trainB. when the train leavesC. which train can I takeD. where does the train go15.—Tom didn’t come to school today. Is he ill?—. He told me he didn’t feel well yesterday afternoon.A. I’m afraid notB. I hope notC. I’m afraid soD. I don’t think soIII.完形填空根据短文内容，从A、B、C、D 四个选项中选出一个能填入相应空格内的最佳答案, 并把答题卡上对应题目的答案标号涂黑。

2020-2021学年重庆八中八年级（下）期末数学试卷一、选择题（本大题共10小题，共31.0分）1. 下列图案中既是轴对称又是中心对称图形的是( )A.B.C.D.2. 定义：如果一个一元二次方程的两个实数根的比值与另一个一元二次方程的两个实数根的比值相等，我们称这两个方程为“相似方程”，例如，(x −3)(x −6)=0的实数根是3或6，x 2−3x +2=0的实数根是1或2，3：6=1：2，则一元二次方程(x −3)(x −6)=0与x 2−3x +2=0为相似方程．下列各组方程不是相似方程的是( )A. x 2−16=0与x 2=25B. (x −6)2=0与x 2+4x +4=0C. x 2−7x =0与x 2+x −6=0D. (x +2)(x +8)=0与x 2−5x +4=03. 已知线段a =4，b =16，线段c 是a 、b 的比例中项，那么c 等于( )A. 10B. 8C. −8D. ±84. 下列因式分解正确的是( )A. 12abc −9a 2b 2=3abc(4−3ab)B. 3m 2n −3mn +6n =3n(m 2−m +2)C. −x 2+xy −xz =x(x +y −z)D. a 2b +5ab −b =b(a 2+5a)5. 已知关于x 、y 的方程组{2ax −3by =2c 3ax +2by =16c的解是{x =4y =2，则关于x 、y 的方程组{2ax −3by +2a =2c3ax +2by +3a =16c的解是( ) A. {x =4y =2B. {x =3y =2C. {x =5y =2D. {x =5y =16. 如图，在△ABC 中，AC >BC ，∠ACB 为钝角．按下列步骤作图：①在边BC 、AB 上，分别截取BD 、BE ，使BD =BE ； ②以点C 为圆心，BD 长为半径作圆弧，交边AC 于点F ；③以点F 为圆心，DE 长为半径作圆弧，交②中所作的圆弧于点G ；④作射线CG 交边AB 于点H ． 下列说法不正确的是( )A. ∠ACH =∠BB. ∠AHC =∠ACBC. ∠CHB =∠A +∠BD. ∠CHB =∠HCB7. 已知a ，b ，c 均为正数，且ab+c =bc+a =ca+b =k ，则下列4个点中，在反比例函数y =kx图象上的点的坐标是( )A. (1,12)B. (1,2)C. (1,−12)D. (1,−1)8. 在Rt △ABC 中，∠C 为直角，AC =4，BC =3，则sinA =( )A.B.C.D.9. 如图，在▱OABC 中C(2,0)，AC ⊥OC ，反比例函数y =kx (k >0)在第一象限内的图象过点A ，且与BC 交于点D ，点D 的横坐标为3，连接AD ，△ABD 的面积为1718，则k 的值为( )A. 4B. 5C. 1718D. 17310. 某天早上小明上学，先步行一段路，因时间紧，他又改乘出租车，结果到校时还是迟到了2分钟，其行程情况如图，若他出门时直接乘出租车(两次车速相同)，则正确的判断是( )A. 仍会迟到2分钟到校B. 刚好按时到校C. 可以提前2分钟到校D. 可以提前5分钟到校二、填空题（本大题共9小题，共35.0分）11. 下面有四个命题：①对角线互相平分的四边形是平行四边形；②一组对边平行，另一组对边相等的四边形是平行四边形；③一组对边相等且一组对角相等的四边形是平行四边形；④一组对边相等且一条对角线平分另一条对角线的四边形是平行四边形；⑤一组对角相等且这一组对角的顶点所连结的对角线平分另一条对角线的四边形是平行四边形：其中，正确的命题的是______(填序号)12.分式√x−2有意义时，x的取值范围是______．13.图中是两个全等的正五边形，则∠α=______．14.若一次函数的图象经过点A(1,2)，点B(2,1)，则函数表达式为______．15.如图，将△ABC沿射线BC方向平移到△DEF的位置，若∠DEF=35°.∠ACB=65°.则∠A的大小是______度．16.有六张正面分别标有数字−2，−1，0，2，3，4的不透明卡片，它们除数字不同外其余均相同．现将它们背面朝上，洗匀后从中任取一张，将该卡片上的数字记为m，则使关于x的分式方程1−mx1−x −1=m2−1x−1有正整数解的概率为______．17.分解因式x2+ax+b，甲看错了a值，分解的结果是(x−3)(x+2)，乙看错了b值，分解的结果是(x−2)(x−3)，那么x2+ax+b分解因式正确的结果应该是______．18.用式子表示x的3倍与y的5倍的和是______ ．19.如图所示，正方形ABCD的面积为12，△ABE是等边三角形，点E在正方形ABCD内，在对角线AC上有一点P，使PD+PE的和最小，则这个最小值为______三、解答题（本大题共9小题，共84.0分）20.计算：(1)2−1−(−0.5)0−sin30°；(2)(x−2)2−x(x−3)；(3)解方程：3−xx−4+14−x=1；(4)解不等式组：{12x+1<321−5(x+1)≤6．21.化简求值：(1+1a )⋅aa2−1−11−a，其中a=−322.如图，点E是正方形ABCD对角线AC上一点，EF⊥AB，EG⊥BC，垂足分别为E，F，若正方形ABCD的周长是40cm．(1)求证：四边形BFEG是矩形；(2)求四边形EFBG的周长；(3)当AF的长为多少时，四边形BFEG是正方形？23.在临江河的治理过程中，要铺设一条长为1000米的管道，由甲、乙两个工程队来完成这一工程.甲队比乙队每天能多铺设20米，且甲队铺设350米所用的时间与乙队铺设250米所用的时间相等．(1)甲、乙两个队每天各能铺设多少米？(2)如果要求工程的工期不能超过10天，那么为两个队分配工程的方法有几种？请设计出来．24.为推动我校科技活动的蓬勃开展，培养中学生的创新精神和实践能力，提高中学生科技素质，我校计划组织一批爱好科技的学生参加第36届山西省青少年科技创新大赛．为了让同学们能更好地备赛，学校打算从在往届比赛中已获得国家一等奖的小亮、小白、小颖、小刚四名同学中随机选择两位同学跟本次参的同学分享创作经验和感受．请用列表或画树状图的方法求出小亮和小颖恰好被同时选中的概率．25.为了做好校园疫情防控工作，校医每天早上对全校办公室和教室进行药物喷洒消毒，她完成3间办公室和2间教室的药物喷洒要19min；完成2间办公室和1间教室的药物喷洒要11min．(1)校医完成一间办公室和一间教室的药物喷洒各要多少时间？(2)消毒药物在一间教室内空气中的浓度y(单位：mg/m3)与时间x(单位：min)的函数关系如图所示：校医进行药物喷洒时y与x的函数关系式为y=2x，药物喷洒完成后y与x成反比例函数关系，两个函数图象的交点为A(m,n).当教室空气中的药物浓度不高于1mg/m3时，对人体健康无危害，校医依次对一班至十一班教室(共11间)进行药物喷洒消毒，当她把最后一间教室药物喷洒完成后，一班学生能否进入教室？请通过计算说明．26.如图，将1至9九个数字写在一张纸条上，将它剪成三段，每段上数字连在一起算一个数，把这三个数相加，使和能被77整除，那么中间一段的数是多少？27.在平面内，C为线段AB外的一点，若以A，B，C为顶点的三角形为直角三角形，则称C为线段AB的直角点．特别地，当该三角形为等腰直角三角形时，称C为线段AB的等腰直角点．(1)如图1，在平面直角坐标系xOy中，点M的坐标为(4,0)，在点P1(0,−1)，P2(5,1)，P3(2,2)中，线段OM的直角点是______；(2)在平面直角坐标系xOy中，点A，B的坐标分别为(1,4)，(1,−6)，直线l的解析式为y=−x+7．①如图2，C是直线l上的一个动点，若C是线段AB的直角点，求点C的坐标；②如图3，P是直线l上的一个动点，将所有线段AP的等腰直角点称为直线l关于点A的伴随点．若⊙O的半径为r，且⊙O上恰有两个点为直线l关于点A的伴随点，直接写出r的取值范围．28.实验与探究(1)在图1、图2、图3中，给出平行四边形ABCD的顶点A、B、D的坐标，写出图1、图2、图3中的顶点C的坐标，它们分别是______ ，______ ，______ ．(2)在图4中，给出平行四边形ABCD的顶点A，B，D的坐标(如图所示)，求出顶点C的坐标(C点坐标用含a，b，c，d，e，f的代数式表示)；归纳与发现(3)通过对图1、图2、图3、图4的观察和顶点C的坐标的探究，你会发现：无论平行四边形ABCD处于直角坐标系中哪个位置，当其顶点C坐标为(m,n)(如图4)时，则四个顶点的横坐标a，c，m，e之间的等量关系为______ ；纵坐标b，d，n，f之间的等量关系为______ (不必证明)．答案和解析1.【答案】C【解析】【分析】此题主要考查了中心对称图形与轴对称图形的概念．轴对称图形的关键是寻找对称轴，图形两部分折叠后可重合，中心对称图形是要寻找对称中心，旋转180度后两部分重合．根据轴对称图形与中心对称图形的概念求解．【解答】解：A.不是轴对称图形，是中心对称图形，故此选项错误；B.不是轴对称图形，也不是中心对称图形，故此选项错误；C.是轴对称图形，是中心对称图形，故此选项正确；D.是轴对称图形，不是中心对称图形，故此选项错误；故选C．2.【答案】C【解析】解：A、方程x2−16=0的实数根是4，x2=25的实数根是5，∵4：4=5：5，∴一元二次方程x2−16=0与x2=25为相似方程；B、方程(x−6)2=0的实数根是6，x2+4x+4=0的实数根是−2，∵6：6=−2：−2，∴一元二次方程(x−6)2=0与x2+4x+4=0为相似方程；C、方程x2−7x=0的实数根是0或7，x2+x−6=0的实数根是−3或2，∵0：7≠−3：2，∴一元二次方程x2−7x=0与x2+x−6=0不是相似方程；D、方程(x+2)(x+8)=0的实数根是−2或−8，x2−5x+4=0的实数根是1或4，∵−2：−8=1：4，∴一元二次方程(x+2)(x+8)=0与x2−5x+4=0为相似方程；故选：C．分别求出选项中两个方程的解，再结合“相似方程”的定义即可确定结论．本题考查了解一元二次方程，读懂题意，正确理解“相似方程”的定义是解题的关键．3.【答案】B【解析】试题分析：根据线段比例中项的概念，a ：b =b ：c ，可得c 2=ab =64，故c 的值可求．∵线段c 是a 、b 的比例中项， ∴c 2=ab =64， 解得c =±8， 又∵线段是正数， ∴c =8． 故选 B ． 考点：图形的相似4.【答案】B【解析】解：A 、12abc −9a 2b 2=3ab(4c −3abc)，故此选项错误； B 、3m 2n −3mn +6n =3n(m 2−m +2)，正确； C 、−x 2+xy −xz =x(−x +y −z)，故此选项错误； D 、a 2b +5ab −b =b(a 2+5a −1)，故此选项错误； 故选：B ．直接利用提取公因式法分解因式，进而判断得出答案．此题主要考查了提取公因式法分解因式，正确找出公因式是解题关键．5.【答案】B【解析】解：∵关于x 、y 的方程组{2ax −3by =2c 3ax +2by =16c的解是{x =4y =2，∴关于x 、y 的方程组{2ax −3by +2a =2c 3ax +2by +3a =16c ，即{2a(x +1)−3by =2c3a(x +1)+2by =16c 的解为{x +1=4y =2，即{x =3y =2， 故选：B ．仿照已知方程组的解，确定出所求方程组的解即可．此题考查了解二元一次方程组，利用了消元的思想，消元的方法有：代入消元法与加减消元法．6.【答案】D【解析】解：根据作图过程可知：∠ACH=∠B，所以A选项正确；∵∠AHC=∠HCB+∠HBC=∠HCB+∠ACH=∠ACB，所以B选项正确；∵∠CHB=∠A+∠ACH=∠A+∠B，所以C选项正确；∵BC≠BH，∴∠CHB≠∠HCB．所以D选项错误．故选：D．根据作图过程可得A选项正确，再根据三角形外角定义可得B和C选项正确，进而可以判断．本题考查了作图−复杂作图、等腰三角形的判定，解决本题的关键是掌握等腰三角形的判定．7.【答案】A【解析】解：已知a，b，c均为正数，且ab+c =bc+a=ca+b=k，根据等比性质，得到k=a+b+cb+c+c+a+a+b =12，因而反比例函数y=kx 的解析式是y=12x，然后检验一下各个选项是否满足解析式，满足解析式的点就在函数图象上．故选：A．根据已知等式，利用比例的等比性质可得出k的值，即可得出反比例函数的关系式，再对各选项逐一分析即可．本题主要考查了函数图象上的点与图象的关系，图象上的点满足解析式，满足解析式的点在函数图象上．解决本题的关键是能利用等比性质求出k的值．8.【答案】C【解析】试题分析：根据题意画出图形，由勾股定理求出AB的长，再根据三角函数的定义解答即可。