选择填空专项冲刺训练参考答案(二)
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2021新高考版高考英语小题优练冲刺训练(二)阅读理解+七选五阅读+完型填空+语法填空Passage AWhat if you could give your child a special gift? A gift that was never the same, always changing? Now what if this gift was free, readily available and lasted forever?Where do you find such a gift? It's easy: Just open your eyes and look up at the sky with your child, and you'll discover "the theatre over your heads which presents all kinds of shows," or "the art gallery above." says Jack Borden, former Boston television reporter who founded "For Spacious Skies (FSS)", a non-profit educational organization with the purpose of "stimulating and sustaining public awareness of the appearance of the sky".Borden's big vision is to bring about "new eyes" in young children in terms of how they see the sky. But the most effective teachers and influencers of children —their parents —need to become "sky aware" themselves in order to pass the gift along.And there's the rub."Could you describe the sky right now, without looking out of your window? Are there clouds? If so, what do they look like? Nine chances out of 10, you don't have a clue about the sky's appearance," says Borden. "We know that people are not looking at the sky. If they perceive the sky at all, it's in the context of the weather or astronomy.""Sky awareness means expanding your horizons so that you begin to see that the sky is the province, not just of the weather reporter, but of the photographer, the artist, the poet, the dreamer. of the physical scientist." says Borden.And it's the province of parents and their children.What parent doesn't want to foster observation ability, imagination, creativity, curiosity and environmental responsibility in their children? "There's a lot to this. There's more to it than I ever dreamed," says Borden.1.What is the special gift for children actually about?A.A new view of the sky. B.A new relationship to nature.C.A good relationship with parents. D.More knowledge about the weather. 2.What does Borden think of parents becoming "sky aware"?A.It is almost impossible. B.It is still unpopular with them.C.It is unimportant for them. D.It is quite unthinkable.3.Why isn't the sky just the province of the weather reporter?A.The sky has a great effect on people's daily life.B.Many other people also show interest in the weather.C.Many other people also play a role in weather report.D.The sky also produces various effects for many others.4.What does the last paragraph focus on?A.Borden's dream. B.Advice to parents.C.Benefits of sky awareness. D.Requirements for cloud watching.Passage BSometimes, the stress, fear and grief feelings can overwhelm(压倒)us. It's fortunate that self-care is more widespread for people of any age to use. It is used to describe guidance on what people can do to get healthy. 1 .Settle your mind. Self-care can help ease the mental burden. What happens to be simple, efficient and free is meditation(冥想). 2 . The positive effect of meditation on anxiety, depression, focus and even physical pain has been so well-established that it is now used in schools, on sports teams and in corporate offices.Roll away stress. When you're under stress, overwhelmed, regular exercise can be one of the first healthy habits to go. Moving your body is a core principle of self-care and one of the best defenses against stress. Melanie Caines, a yoga teacher, suggests movement needn't mean doing a serious workout every day. "A little goes a long way. 3 . " she says.4 An important self-care way is to be mindful about what you're eating and consider adding some nutritional support. This means a balanced diet that is right for your needs. But one commonly overlooked piece, according to Toronto naturopathic(自然疗法的)doctor Nikita Sander, is Vitamin D. She notes that the nutrient is protective in many ways and h key for mental health. It helps protect against mood disorders like depression.Generally speaking, self-care, as the name suggests, is whatever you make it. 5 You can develop your own self-care routine, a set of practices and habits to follow.A. Get your vitamins.B. Keep balanced diets.C. Here are some starting points.D. Self-care can extend in many directions.E. Gentle exercises can do a lot to relax your entire body.F. That is, letting your mind wander freely allows it to settle.G. It can be difficult to maintain a regular meditation practice.Passage CI had always been warmly praised for my shooting ability when I was in high school. But when I went to Ohio State, I discovered that everyone on the team was 1 in his hometown.To win a starting job on the team, I had figured I would have to 2 the coach with my shooting ability. But it 3 that the team was already full of attacking players and what it needed was someone to 4 on defence(防御). Unwillingly, I decided to take that role, but didn't expect the 5 was to make all the difference to me later.One day, when we were 6 for a game against the Bucks, I was called out by the coach, Milwaukee, who gave me the 7 to guard our court. Though feeling a bit 8 , I accepted. Throughout the game, I continued playing the role.Then, near the end of the game, in a(an) 9 to widen the gap, Milwaukee gave me a precious 10 . He asked me to organize an attack. Driving up the middle of the court, I 11 the ball. It was a 12 three-point play and minutes later the championship was ours.Standing there in that circle of cheering audience, I came to 13 the importance of teamwork, Just as Milwaukee said, “14 teams often have one or two players who stand out; good teams have five who work together. It is amazing what can be achieved when no one cares who gets the 15 .”1.A.ordinary B.anxious C.inexperienced D.excellent 2.A.bless B.impress C.help D.equip 3.A.turned out B.turned to C.turned up D.turned down 4.A.count B.focus C.wait D.call 5.A.problem B.approach C.comment D.decision6.A.looking B.playing C.applying D.preparing 7.A.responsibility B.potential C.comfort D.change 8.A.cheerful B.satisfied C.disappointed D.frightened 9.A.mood B.attempt C.rush D.position 10.A.opportunity B.method C.suggestion D.lesson 11.A.caught B.kicked C.shot D.held12.A.rare B.typical C.key D.possible 13.A.wish B.achieve C.advise D.realize 14.A.Poor B.Losing C.Strong D.Capable 15.A.income B.praise C.support D.promotionPassage DSmell, more than any other sense, is deeply rooted in memory. It is believed by scientists 1.smells can recall feelings of distant memories. The scientists say 2.area of the brain assigns memories to smells and stores 3.(they) for decades. The area can instantly recall the memories with great clearness years later if a person encounters the smell again. Christina Strauch, from the Ruhr University in Germany, says smells 4.(store) in the olfactory brain. The word “olfactory” means anything rel ated 5.the sense of smell.Many smells can transport us back to our childhood. Smells from cookies baking in the kitchen or the smell of a home-made dish can bring back 6.(amaze) memories of growing up. Some smells can take you away to another point in time. Some smells can make you wish you 7.(be) back in the past, or make you want to escape, which depends on whether the smell has a positive or negative 8.(associate). Some doctors partly depend on this for their patients. Smells can even encourage you 9.(buy) things in stores. Many stores introduce certain smells to awake particular memories, 10.can make people buy things they loved years ago.参考答案:A1.根据第三段“Borden's big vision is to bring about "new eyes" in young children in terms of how they see the sky.(博登的远大愿景是为孩子们带来“新眼睛”,让他们知道如何看待天空)”可知,就如何看天空这方面来说,博登的愿景就是在孩子身上培养对天空有新的看法。
历年中考真题选择题专练及答案(二)总分100(每小题1分)1. Tom usually goes fishing __ Sunday morning.A. atB. onC. for2. —Peter, is this your pen?—Yes, it' s __. Many thanks. I looked for it everywhere.A. mineB. meC. I3. —Where did you go yesterday, Rick?—I went to see a because I had a cold.A. teacherB. doctorC. reporter4. Lady Gags is very popular, and she by many boys and girls at school.A. lovesB. is lovingC. is loved5. —Excuse me, whose Japanese book is this?—It be Tom ' s. In our class, only he is studying Japanese.A. mustB. can'tC. would6. It' s interesting that there are many people speak French in Canada.A. whichB. whereC. who7. Parents often ask their kids __ their internet friends because the kids may be in danger.A. to meetB. not to meetC. meeting8. Look! Peter TV happily, but his parents are busy in the kitchen.A. is watchingB. watchesC. watched9. —Hey, Tony, You look so tired today.—-I __ until 12 o' clock last night for the math test.A. woke upB. stayed upC. grew up10. My cousin knows a lot about geography, __ he is only four years old.A. becauseB. soC. although11. Some scientists think that it will take __ of years to make robots do most work for humans.A. hundredsB. hundredC. thousand12. Please keep quiet, everybody! I have important to tell you.A. nothingB. somethingC. everything13. This T-shit is not large enough. Please show me a one,A. largeB. largerC. largest14. —I can' t find Mike. Could you tell me ?—He is in the library.A. what h e isB. how he isC. where he is15. —Jack, let's go to see the movie Harry Potter.—Oh, I it many times. So I don' t want to see it.A. have seenB. seeC. will see16. —I want to know when Mr. Brown will arrive.—When he , I will tell you.A. will arriveB. arrivedC. arrives17. —I’m very tired. I can’t go any further, Jenny.—,Tommy. You can do it!A. Come onB. You are rightC. That’s OK18. he has little knowledge, the old worker has a lot of experience.A. Although.B. Because.C. If19. One of the advantage of playing guitar is that it can give you a great deal of pleasure.A. aB. theC. 不填20. We forgot to bring our tickets , but please let us enter, ?A. do youB. shall weC. will you21. —Have you known Dr. Jackson for a long time?—Yes, since she the Chinese Society.A. joinedB. joinsC. has joined22. When asked what they needed most, the kids said they wanted to important and loved.A. turnB. soundC. feel23. Sarah had her washing machine yesterday, but it doesn’t work now.A. repairB. repairedC. to repair24. Tony is very nice. He is the most enjoyable person I .A. meet everB. have ever metC. had ever met25. A typhoon hit this area with heavy rains and winds strong as what happened in 2008.A. asB. soC. too26. In order to finish the project, we’ll have to work hours a day.A. more twoB. two moreC. two another27. If you can’t decide which of the two books to borrow, why don’t you take ? I won’t read themthis week.A. allB. eitherC. both28. —Do you have any problems if you five minutes to read?—Well, I’m thinking about the new words. There are too many.A. giveB. are givenC. will be given29. The digital camera it very popular, but some still too much.A. costB. spendC. pay30. —Have you got any idea for the summer vacation?—I don’t mind . It will be OK if there is sun, sea and beach.A. where do we goB. where we goC. when we go31. —It’s a top secret.—Yes, I see. I will keep the secret you and me.A. withB. amongC. between32.—- Which do you like ______, summer or winter? —I’d prefer winter.A better B. best C. good D. well33. Excuse me, would you mind _______ your voice down, please?A. to keepB. keepingC. keepD. kept34. I’m not sure when the plane will __________ and when it will land.A. take offB. run offC. open upD. stay up35. Hurry up! If we miss ____ last bus, we’ll have to get home by _____taxi.A. a;不填B. the; aC. the;不填D. a; a36. When I called the bus service, I _______ that there was no more bus.A. was tellingB. was toldC. has toldD. had told37. School students _______ smoke because it is against the school rules.A needn’t B. couldn’t C. won’t D. mustn’t38. Please tell me the truth, _______ I can decide how to help you next step.A. soB. orC. butD. for39.You were ________ to close the windows. Why were you so careless?A. allowedB. believeC. supposedD. caused40.—-Hey, July.—- ____________?—- I need your help.A. Oh, reallyB. What’s upC. How are youD. All right41. Linda has bought a large house _______ a swimming pool.A with B. in C. on D. from42. I hope Tim can come to my birthday party. Then we ____ a much happier time.A. haveB. hadC. will haveD. have had43. —- What about going to the South Lake for a picnic next weekend?—- OK. But I’m not sure _______ it will rain.A. whyB. whereC. whenD. whether44. David suddenly felt nervous. ___________, it was his first time to go on stage.A. At leastB. After allC. At onceD. At all45. We make it a rule that each of us _________ the bedroom one day a week.A. has cleanedB. have cleanedC. cleansD. clean46. _________ this rock music, please. I’m afraid some people can’t stand the noise!A Stopping B. stop C. Stops D. Stopped47. Everyone in the hall knew me, but I did not know ________.A. himB. herC. themD. those48. _____I was in the US, I made a lot of American friends.A. whileB. AlthoughC. UnlessD. Until49. I began watching here an hour ago, but now nothing ________ yet.A. happensB. will happenC. happenedD. has happened50. I can never forget the stories ________ my grandma told me.A. whatB. whoC. themD. that51. –Mom,I have done a good job in today's exam.—Wonderful! That's a good_____. Come on, and you will do better in the following exams.A. startB. informationC. messageD. idea52. Mike, _____ iPad is on the bed, but where is_______?A. hers; hisB. your; mineC. yourself; himD. her; your53. He is so poor. The________ thing is a black and white TV set in his house.A cheapest B. cheaper C. most expensive D. more expensive54. —I wonder how you have improved your spoken English so fast, Li Lei.—________ chatting with my foreign friend, Mike. He's been here for some time, you know.A. ByB. WithC. InD. On55. He began to like ____________ music from very early age, and __________ music of the TV play A Step Into the Past(《寻秦记》)was created by him.A. the;theB. a;theC.不填;theD. 不填;不填56. —When can 1 see Tom?—He is watching an English film. It began at 8, and __________ on for another 30 minutes.A. has beenB. wasC. had beenD. will be57. The little girl comes to the Children's Palace _________ the guitar on Sundays.A. practicing to playB. to practice to playC. to practice playingD. practices playing58. It always ____the old man one hour to walk in Daqian Park after supper, which makes him healthy.A. costsB. paysC. spendsD.takes59. We should choose a healthy life style, _______ a low carbon(低碳) life.A. recentlyB. nearlyC. hardlyD. especially60. The monitor had _________ the test papers before the teacher came into the classroom.A. given outB. given upC. got overD. got along with61. Mrs. Li has never been to the top of Mt Emei to see the sunrise since Mr. Li left Emei city, ______?A. hasn't sheB. didn't heC. has sheD. did he62. Gorge asked me when he passed by just now_______.A. what time did the film beginB. where Tom had goneC. whether have 1 finished the reportD. how 1 will go to Chengdu63. Li Lei realized __________ necessary for him to get up early to do some exercise for he found he was getting fatter and fatter.A. itB. thatC. oneD. this64. —Excuse me. Could I get into the room to get my book back?— __________, but no one except the head master is allowed to enter it from yesterday on.A. Of course, go aheadB. All rightC. I'm sorryD. Never mind65. —Oh, he_________ be Li Ming. I know him well.—No, it _________ be him. He's gone to Neijiang for a meeting.A. can; doesn't have toB. must; can'tC. need; mustn'tD. may; may not66. He was reading yesterday's China Daily_________ he was wanted on the phone.A. asB. afterC. whileD. when67._____ _____ is going to see the film Titanic again because this year marks the 100 years since the Titanic sank(沉没) in the ocean.A. Not only Lily but also her parentsB. Lily, with her parents,C. Both Ben and DianaD. Neither Ben nor Diana68. A professor(教授) from a university ________ is tired of the city life has moved up to a high mountain.A. whoB. whichC. whomD. where69. Sarah's father is wondering if he_ to the airport to meet her when she________ there.A. will go; arrivesB. goes; arrivesC. has gone; will arriveD. is going; arrived70. —________do you call your parents ?—Very of ten, and each time, five minutes.A. WhenB. How longC. How manyD. How often71. 请选出含/id/发音的单词:________A. wantedB. laughedC. lived72. "You can't have them all. You can choose the kite the toycar," said the mother.A. either; orB. not only; but alsoC. both; and73. — I hear your friend is visiting San Ya again. Is it the second time for him?— Yes, and he will come for time next spring.A. a thirdB. a secondC. the third74. — Li Na won the tennis championship in the French Open on June 4, 2011.— We take pride in her. She is the first Asian professional tennis player to win it.选出意思与划线部分相同的选项:A. are interested inB. are terrified ofC. are proud of75. -You aren't a student now, are you?—, don't you remember me in the classroom ten minutes ago?A. No; seeingB. Yes; seeingC. No; to see76. —When are you going to have your hair ?—This afternoon.A. cutB. to cutC. cutting77. It will be if you buy a return ticket on the train when you travel inEngland.A. much cheapB. more cheaplyC. much cheaper78. I think teenagers should drive. They are not serious enough.A. be allowed toB. not be allowed toC. not allow to79. —Can you tell me ?— By doing more exercises and speaking.A. how I can improve my EnglishB. how do I deal with my EnglishC. what's wrong with my English80. —Have you heard that some bad thing would happen in 2012?—Don't worry! The news be true.A. mustn'tB. may notC. needn't81. You should keep the window because the room is too hot.A. openB. openingC. opened82. Did you find very interesting to play volleyball?A. thisB. thatC. it83. — How soon can you finish this job?— Two days enough for me to finish the work. I need a week.A. isn'tB. aren'tC. is84. They have got such a table.A. round wooden brownB. round brown woodenC. brown round wooden85. — What's your favorite ?— Summer. Because I can swim in rivers.A. seasonB. subjectC. music86.—You are on the phone, Mary.— Yes, mum. .A. wanted; I'm comingB. called; I'm comingC. needed; I'll come87. — A subway will be built in our hometown before 2015.—! Will it pass my house?A. What an excited newsB. What exciting newsC. How exciting news88. — Jackie Chan has donated dollars to charity.— He is an example to us all.A. thousandB. thousands ofC. thousand of89. — Who also did this wonderful job, Uncle Wang?— It's .A. meB. IC. my90. Which of the following is caused by the earth's turning around the sun?A. The rising and setting (落下) of the sun and moon.B. The change of spring, summer, autumn and winter of the year.C. The change of the day and night.91. I think it's not polite to laugh others.A. inB. atC. over92. Your father used to eat meal, ?A. did youB. didn't youC. didn't he93. Practicing in groups is good _ _ us to learn English.A, at B. in C. for94. Don't up English. It's very important.A. giveB. hurry C, stay95. What would happen if he _ _ back h ome?A. goB. goesC. went96, It’s quite exciting me _ _ the Internet.A. for, surfB. for, to surfC. for, for surf97.—Is this your e-dictionary?—No, is in the backpack,A. mineB. yoursC. my98.—Math is too difficult, I nearly give it up.—Please don't, nothing is if you put your heart into it.A. importantB. impossibleC. interesting99. — _ _ weather! It's raining!—Bad luck! We can't go climbing today.A. What badB. How badC. What fine 100. I think should not he allowed to drive.A. sixteen years oldB. sixteen-year-oldC. sixteen-year-oldsKey : 历年中考真题选择题专练及答案(二)1. A2. A 3 .B 4. C 5. A6. C7. B8. A9. B 10.C11.A 12..B 13.B 14.C15.A16.C 17.A 18.A 19.B 20.C21.A 22.C 23.B 24.B 25.A26.B 27.C 28.B 29.A 30.B31.C 32.A 33.B 34.A 35.C36.B 37.D 38.A 39.C 40.B41.A 42.C 43.D 44.B 45.C46.B 47.C 48.A 49.D 50.D51.A 52.B 53.C 54.A 55.C56.D 57.C 58.D 59.D 60.A61.C 62.B 63.A 64.C 65.B66.D 67.B 68.A 69.A 70.D71.A 72.A 73.A 74.C 75.B76.A 77.C 78.B 79.A 80.B81.A 82.C 83.A 84.B 85.A86.A 87.B 88.B 89.A 90.B91. B 92.C 93.C 94.A 95.C96. B 97.A 98.B 99.A 100C。
一、选择题(每题2分,共20分)1. 下列词语中,字形、字音都正确的一项是:A. 惊愕(jīng è)沉默(chén mò)雕琢(diāo zhuó)B. 惊慌(jīng huāng)沉思(chén sī)雕刻(diāo kè)C. 惊恐(jīng kǒng)沉默(chén mò)雕镂(diāo lòu)D. 惊悚(jīng sǒng)沉重(chén zhòng)雕饰(diāo shì)答案:C2. 下列句子中,没有语病的一项是:A. 为了提高我们的学习成绩,老师给我们安排了大量的作业。
B. 由于天气原因,今天的运动会不得不推迟举行。
C. 我觉得这本书写得非常有趣,推荐给大家阅读。
D. 他不仅学习好,而且工作能力强,是我们学习的榜样。
答案:C3. 下列词语中,形近音同的一项是:A. 谨慎(jǐn shèn)禁忌(jìn jì)晕倒(yūn dǎo)B. 端庄(duān zhuāng)沉稳(chén wěn)懒惰(lǎn duò)C. 稳健(wěn jiàn)谨慎(jǐn shèn)舒畅(shū chàng)D. 精确(jīng què)精神(jīng shén)淋漓(lín lí)答案:A4. 下列句子中,使用了比喻修辞手法的一项是:A. 月亮像一只银盘高悬在夜空中。
B. 春天的柳树,像一位美丽的姑娘,梳理着她的长发。
C. 那只小鸟在枝头欢快地歌唱。
D. 小明的学习成绩像火箭一样直线上升。
答案:B5. 下列词语中,不属于节日名称的一项是:A. 春节B. 中秋节C. 劳动节D. 圣诞节答案:D二、填空题(每题2分,共20分)6. 《离骚》的作者是________,这首诗主要表达了作者________。
福建中考语文冲刺卷及答案(二)注意:请把所有答案填涂或书写到答题卡上!请不要错位、越界答题!在本试题上答题无效。
一、积累与运用(19分)1.补写出下列句子中的空缺部分。
(10分)(1)不应有恨,。
(苏轼《水调歌头》)(2),芳草萋萋鹦鹉洲。
(崔颢《黄鹤楼》)(3)东皋薄暮望,。
(王绩《野望》)(4)是故学然后知不足,。
(《虽有嘉肴》)(5),千嶂里,长烟落日孤城闭。
(范仲淹《渔家傲·秋思》)(6)年少万兜鍪,。
(辛弃疾《南乡子·登京口北固亭有怀》)(7)《望岳》中,诗人化用了“孔子登泰山而小天下”一句,来表达自己敢于攀登顶峰,俯视一切的句子是,。
(8)《<论语>十二章》中告诫我们只有把学习和思考结合起来,才能学到切实有用的知识的句子是,。
2.下列各句中有语病的一项是()(3分)A.2019年生物多样性政府间科学政策平台的专家们所做评估显示,目前全球物种灭绝速度已经失控,而且还在不断加快。
B.3月3日是世界野生动植物日,联合国秘书长在致辞中发出呼吁:我们有责任维护和可持续利用地球上的多样生命。
C.随着人口和需求持续迅猛增长,我们不断用竭泽而渔的方式压榨自然资源,其中也包括野生动植物和它们的栖息地。
D.在全球近800万物种之中,有大约100万左右的物种面临灭绝威胁,70%的热带雨林因不可持续的土地使用而退化。
3.阅读下面的文字,按要求作答。
(6分)此次疫情,诡①(A.guǐB.wuǐ)异险恶,无疑是民族国家之灾难。
但人类最终都以坚强的意志和高超的智慧使病毒败走。
灾难甲(A.绝非B.不仅)是一个国家的,也是全人类的。
事态的màn②(A.漫B.蔓)延,再度告诫人类,地球只是一个小小的村庄。
此次疫情,中华民族表现出的是临危不惧,是阔达胸怀,是强大的组织力与行动力,当之无愧于人类。
这场乙(A.声势浩大B.气势磅礡)的全民战役,是人类历史上难忘的一幕,最终的胜利者必将是我们。
贵州省贵阳市2020年数学中考基础冲刺训练(二)一.选择题(每题3分,满分30分)1.已知x﹣2y=﹣2,则3+2x﹣4y的值是()A.0 B.﹣1 C.3 D.52.如图,在△ABC中有四条线段DE,BE,EF,FG,其中有一条线段是△ABC的中线,则该线段是()A.线段DE B.线段BE C.线段EF D.线段FG3.下面是几个一样的小正方体摆出的立体图形的三视图,由三视图可知小正方体的个数为()A.6个B.5个C.4个D.3个4.以下问题,适合用普查的是()A.调查某种灯泡的使用寿命B.调查中央电视台春节联欢会的收视率C.调查我国八年级学生的视力情况D.调查你们班学生早餐是否有喝牛奶的习惯5.如图,在菱形ABCD中,AB=2,∠B=60°,E、F分别是边BC、CD中点,则△AEF 周长等于()A.B.C.D.36.数轴上的点A表示的数是a,当点A在数轴上向右平移了6个单位长度后得到点B,若点A和点B表示的数恰好互为相反数,则数a是()A.6 B.﹣6 C.3 D.﹣37.如果方程x2﹣8x+15=0的两个根分别是Rt△ABC的两条边,△ABC最小的角为A,那么tan A的值为()A.B.C.D.或8.用蓝色和红色可以混合在一起调配出紫色,小明制作了如图所示的两个转盘,其中一个转盘两部分的圆心角分别是120°和240°,另一个转盘两部分被平分成两等份,分别转动两个转盘,转盘停止后,指针指向的两个区域颜色恰能配成紫色的概率是()A.B.C.D.9.在平面直角坐标系xOy中,若一次函数y=kx﹣1(k≠0)的图象经过点P,且y的值随x 值的增大而减少,则点P的坐标可以为()A.(2,1)B.(﹣2,1)C.(﹣2,﹣1)D.(2,﹣1)10.如图,抛物线y=x2﹣7x+与x轴交于点A、B,把抛物线在x轴及其下方的部分记作C1,将C1向左平移得到C2,C2与x轴交于点B、D,若直线y=x+m与C1、C2共有3个不同的交点,则m的取值范围是()A.﹣<m<﹣B.﹣<m<﹣C.﹣<m<﹣D.﹣<m<﹣二.填空题(每题4分,满分20分)11.一次数学测试后,某班40名学生的成绩被分为5组,第1﹣4组的频数分别为12、10、6、8,则第5组的频率是.12.如图,点P是反比例函数y=(k≠0)的图象上任意一点,过点P作PM⊥x轴,垂足为M.若△POM的面积等于2,则k的值等于.13.如图,正六边形ABCDEF的顶点B、C分别在正方形AGHI的边AG、GH上,如果AB=4,那么CH的长为.14.若不等式组的解集是﹣1<x≤1,则a=,b=.15.如图,在矩形ABCD中,AB<BC,点E为CD边的中点,连接AE并延长与BC的延长线交于点F,过点E作EM⊥AF交BC于点M,连接AM与BD交于点N,现有下列结论:①AM=MF;②ME2=MC•AM;③=(sin∠DAE)2;④点N是四边形ABME 的外接圆的圆心,其中正确结论的序号是.三.解答题16.(10分)体育老师为了解本校九年级女生1分钟“仰卧起坐”体育测试项目的达标情况,从该校九年级136名女生中,随机抽取了20名女生,进行了1分钟仰卧起坐测试,获得数据如下:收集数据:抽取20名女生的1分钟仰卧起坐测试成绩(个)如下:38 46 42 52 55 43 59 46 253835 45 51 48 57 49 47 53 5849(1)整理、描述数据:请你按如下分组整理、描述样本数据,把下列表格补充完整:范围25≤x≤2930≤x≤3435≤x≤3940≤x≤4445≤x≤4950≤x≤5455≤x≤59人数(说明:每分钟仰卧起坐个数达到49个及以上时在中考体育测试中可以得到满分)(2)分析数据:样本数据的平均数、中位数、满分率如下表所示:平均数中位数满分率46.8 47.5 45%得出结论:①估计该校九年级女生在中考体育测试中1分钟“仰卧起坐”项目可以得到满分的人数为;②该中心所在区县的九年级女生的1分钟“仰卧起坐”总体测试成绩如下:平均数中位数满分率45.3 49 51.2%请你结合该校样本测试成绩和该区县总体测试成绩,为该校九年级女生的1分钟“仰卧起坐”达标情况做一下评估,并提出相应建议.17.(8分)某商场销售进价为每件x元的上衣,先按进价的2倍作为定价,而实际销售时按定价打八折出售.(1)试用代数式表示:①每件上衣最初的定价为元;②每件上衣打八折后的销售价为元;③n件上衣打八折后的利润为元;(2)若该商场这次共购进每件120元的上衣100件,按以上办法售出80件后,其余按定价的六折销售全部卖完,问该商场在这批上衣买卖中,除支付销售费用1000元外,盈亏情况如何?18.如图,在Rt△ABC中,∠ACB=90°,AC=4,BC=3,点D是边AC的中点,CF⊥BD,垂足为点F,延长CF与边AB交于点E.求:(1)∠ACE的正切值;(2)线段AE的长.19.(10分)某水果店2400元购进一批葡萄,很快售完;又用5000元购进第二批葡萄,所购件数是第一批的2倍,但进价比第一批每件多了5元.(1)求第一批葡萄每件进价多少元?(2)若以每件150元的价格销售第二批葡萄,售出80%后,为了尽快售完,决定打折促销,要使第二批葡萄的销售利润不少于640元,剩余的葡萄每件售价至少打几折(利润=售价﹣进价)?20.(10分)如图,在等腰Rt△ABC中,∠BAC=90°,延长BA至点D,连结DC,过点B 作BE⊥DC于点E,F为BC上一点,FC=FE.连结AF,AE.(1)求证:FA=FE.(2)若∠D=60°,BC=10,求△AEF的周长.21.(10分)某种机器使用若干年后即被淘汰,该机器有一易损零件,为调查该易损零件的使用情况,随机抽取了100台已被淘汰的这种机器,经统计:每台机器在使用期内更换的该易损零件数均只有8,9,10,11这四种情况,并整理了这100台机器在使用期内更换的该易损零件数,绘制成如图所示不完整的条形统计图.(1)请补全该条形统计图;(2)某公司计划购买一台这种机器以及若干个该易损零件,用上述100台机器更换的该易损零件数的频率代替一台机器更换的该易损零件数发生的概率.①求这台机器在使用期内共更换了9个该易损零件的概率;②若在购买机器的同时购买该易损零件,则每个200元;若在使用过程中,因备用该易损零件不足,再购买,则每个500元.请你帮该公司用花在该易损零件上的费用的加权平均数进行决策:购买机器的同时应购买几个该易损零件,可使公司的花费最少?22.(10分)为满足市场需求,某超市在新年来临前夕,购进一款商品,每盒进价是40元.超市规定每盒售价不得少于45元.根据以往销售经验发现;当售价定为每盒45元时,每天可以卖出700盒,如果每盒售价每提高1元,则每天要少卖出20盒.(1)试求出每天的销售量y(盒)与每盒售价x(元)之间的函数关系式;(2)当每盒售价定为多少元时,每天销售的利润P(元)最大?最大利润是多少?23.如图,AB为⊙O的直径,且AB=4,点C在半圆上,OC⊥AB,垂足为点O,P为半圆上任意一点(不与点C重合),过P点作PE⊥OC于点E,设△OPE的内心为M,连接OM、PM.(1)求∠OMP的度数;(2)当点P在半圆上从点B运动到点A时,求内心M所经过的路径长.24.我们知道:在小学已经学过“正方形的四条边都相等,正方形的四个内角都是直角”,试利用上述知识,并结合已学过的知识解答下列问题:如图1,在正方形ABCD中,G是射线DB上的一个动点(点G不与点D重合),以CG 为边向下作正方形CGEF.(1)当点G在线段BD上时,求证:∠DCG=∠BCF;(2)连接BF,试探索:BF,BG与AB的数量关系,并说明理由;(3)若AB=a(a是常数),如图2,过点F作FT∥BC,交射线DB于点T,问在点G 的运动过程中,GT的长度是否会随着G点的移动而变化?若不变,请求出GT的长度;若变化,请说明理由.25.如图,直线y=x+2与x轴交于点B,与双曲线C1:(x>0)交于点A,且A点的横坐标为2.(1)求双曲线C1的函数解析式;(2)若P为C1上的一动点,连接PO.①将PO绕O点顺时针旋转90°,得到点P′,问P′是否在某定曲线C1上运动,若是,试求C1的解析式,若不是,说明理由;②若△AOP的面积为,直接写出P点坐标为.参考答案一.选择题1.解:由x﹣2y=﹣2,得到原式=3+2(x﹣2y)=3﹣4=﹣1.故选:B.2.解:根据三角形中线的定义知线段BE是△ABC的中线,故选:B.3.解:综合三视图,这个立体图形的底层应该有3个,第二层应该有1个小正方体,因此构成这个立体图形的小正方体的个数是3+1=4个.故选:C.4.解:A、调查某种灯泡的使用寿命,不能使用普查,错误;B、调查中央电视台春节联欢会的收视率被调查的对象都较大,不能使用普查,错误;C、调查我国八年级学生的视力情况被调查的对象都较大,不能使用普查,错误;D、调查你们班学生早餐是否有喝牛奶的习惯被调查的对象较小,故D宜使用普查;故选:D.5.解:如图,连接AC,∵菱形ABCD,∠B=60°,∴△ABC是等边三角形,∵点E是BC的中点,∴AE=,∠EAC=30°,同理可得:AF=,∠FAC=30°,∴AE=AF,∠EAC=∠FAC,∴△AEF是等边三角形,∴△AEF的周长=3×=3.故选:B.6.解:由题意可得:B点对应的数是:a+6,∵点A和点B表示的数恰好互为相反数,∴a+a+6=0,解得:a=﹣3.故选:D.7.解:x2﹣8x+15=0,(x﹣3)(x﹣5)=0,则x﹣3=0,x﹣5=0,解得x=3或5,①当3和5为直角边时:tan A=.②当5为斜边时,另一直角边为4,tan A=.故选:D.8.解:列表如下:红红蓝红紫蓝紫紫共有6种情况,其中配成紫色的有3种,所以恰能配成紫色的概率==,故选:A.9.解:把(2,1)代入一次函数y=kx﹣1得:2k﹣1=1,k=1,因此不可以;把(﹣2,1)代入一次函数y=kx﹣1得:﹣2k﹣1=1,k=﹣1,因此可以;故选:B.10.解:∵抛物线y=x2﹣7x+与x轴交于点A、B∴B(5,0),A(9,0)∴抛物线向左平移4个单位长度∴平移后解析式y=(x﹣3)2﹣2当直线y=x+m过B点,有2个交点∴0=+mm=﹣当直线y=x+m与抛物线C2相切时,有2个交点∴x+m=(x﹣3)2﹣2x2﹣7x+5﹣2m=0∵相切∴△=49﹣20+8m=0∴m=﹣如图∵若直线y=x+m与C1、C2共有3个不同的交点,∴﹣<m<﹣故选:C.二.填空题11.解:根据题意得:40﹣(12+10+6+8)=40﹣36=4,则第5组的频率为4÷40=0.1,故答案为:0.1.12.解:∵△POM的面积等于2,∴|k|=2,而k<0,∴k=﹣4,故答案为:﹣4.13.解:正六边形的内角的度数==120°,则∠CBG=180°﹣120°=60°,∴∠BCG=30°,∴BG=BC=2,CG=BC=2,∴AG=AB+BG=6,∵四边形AGHI是正方形,∴GH=AG=6,∴CH=HG﹣CG=6﹣2,故答案为:6﹣2.14.解:∵解不等式①得:x>1+a,解不等式②得:x≤﹣∴不等式组的解集为:1+a<x≤﹣∵不等式组的解集是﹣1<x≤1,∴1+a=﹣1,﹣=1,解得:a=﹣2,b=﹣3故答案为:﹣2,﹣3.15.解:∵四边形ABC都是正方形,∴AD∥BF,∴∠DAE=∠F,∵∠AED=∠FEC,DE=EC,∴△ADE≌△FCE(AAS),∴AE=EF,∵ME⊥AF,∴MA=NF,故①正确,∵∠EMC=∠EMF,∠ECM=∠MEF,∴△MEC∽△MFE,∴ME:MF=MC:ME,∴ME2=MC•MF=MC•AM,故②正确,∵∠AEM=90°,∠ADE=∠ECM=90°,∴∠AED+∠MEC=90°,∠MEC+∠EMC=90°,∴∠AED=∠EMC,∴△ADE∽△ECM,∴=()2=()2=(tan∠DAE)2,故③错误,∵∠ABM=∠AEM=90°,∴A,B,M,E四点共圆,∴四边形的外接圆的圆心是线段AM的中点,显然点N不是AM的中点,故④错误.故答案为①②.三.解答题16.解:(1)补充表格如下:范围25≤x≤2930≤x≤3435≤x≤3940≤x≤4445≤x≤4950≤x≤5455≤x≤59人数 1 0 3 2 7 3 4 (2)①估计该校九年级女生在中考体育测试中1分钟“仰卧起坐”项目可以得到满分的人数为136×≈61,故答案为:61;②从平均数角度看,该校女生1分钟仰卧起坐的平均成绩高于区县水平,整体水平较好;从中位数角度看,该校成绩中等水平偏上的学生比例低于区县水平,该校测试成绩的满分率低于区县水平;建议:该校在保持学校整体水平的同时,多关注接近满分的学生,提高满分成绩的人数.17.解:(1)①每件上衣最初的定价为2x(元);②每件上衣打八折后的销售价为2x•0.8=1.6x(元);③n件上衣打八折后的利润为n•(1.6x﹣x)=0.6xn(元);(2)0.6×120×80+2×120×0.6×20﹣120×20﹣1000=5240(元),所以该商场在这批上衣买卖中盈利5240元.故答案为2x,1.6x,06xn.18.解:(1)∵∠ACB=90°,∴∠ACE+∠BCE=90°,又∵CF⊥BD,∴∠CFB=90°,∴∠BCE+∠CBD=90°,∴∠ACE=∠CBD,∵AC=4且D是AC的中点,∴CD=2,又∵BC=3,在Rt△BCD中,∠BCD=90°.∴tan∠BCD==,∴tan∠ACE=tan∠CBD=;(2)过点E作EH⊥AC,垂足为点H,在Rt△EHA中,∠EHA=90°,∴tan A=,∵BC=3,AC=4,在Rt△ABC中,∠ACB=90°,∴tan A==,∴=,设EH=3k,AH=4k,∵AE2=EH2+AH2,∴AE=5k,在Rt△CEH中,∠CHE=90°,∴tan∠ECA==,∴CH=k,∴AC=AH+CH=k=4,解得:k=,∴AE=.19.解:(1)设第一批葡萄每件进价x元,根据题意,得:×2=,解得x=120.经检验,x=120是原方程的解且符合题意.答:第一批葡萄每件进价为120元.(2)设剩余的葡萄每件售价打y折.根据题意,得:×150×80%+×150×(1﹣80%)×0.1y﹣5000≥640,解得:y≥7.答:剩余的葡萄每件售价最少打7折.20.(1)证明:∵BE⊥DC,∴∠EBC+∠ECB=∠CEF+∠BEF=90°,∵FC=FE,∴∠ECB=∠CEF,∴∠EBC=∠BEF,∴BF=FE=FC,在Rt△BAC中,AF是斜边BC上的中线,∴FA=FC,∴FA=FE;(2)解:∵∠D=60°,∠BAC=90°,∴∠ACD=30°,∵△ABC为等腰直角三角形,∴∠ABC=∠ACB=45°,∴∠ECF=∠ACD+∠ACB=30°+45°=75°,由(1)得:FA=FE,AF是斜边BC上的中线,∴AF⊥BC,AF=BC=5,∵FC=FE,∴∠EFC=180°﹣2∠ECF=180°﹣2×75°=30°,∴∠AFE=90°﹣30°=60°,∴△AEF是等边三角形,∴△AEF的周长=3AF=3×5=15.21.解:(1)100﹣20﹣50﹣20=10,补全的条形统计图如图所示:(2)①这台机器在使用期内共更换了9个该易损零件的概率为:P==;②购买机器的同时购买8个该易损零件200×0.2+500×0.8=440元,购买机器的同时购买9个该易损零件200×0.5+500×0.5=350元,购买机器的同时购买10个该易损零件200×0.1+500×0.9=470元,购买机器的同时购买11个该易损零件200×0.2+500×0.8=440元,因此,购买机器的同时应购买9个该易损零件,可使公司的花费最少.22.解:(1)由题意得销售量y=700﹣20(x﹣45)=﹣20x+1600(x≥45);(2)P=(x﹣40)(﹣20x+1600)=﹣20x2+2400x﹣64000=﹣20(x﹣60)2+8000,∵x≥45,a=﹣20<0,=8000元∴当x=60时,P最大值即当每盒售价定为60元时,每天销售的利润P(元)最大,最大利润是8000元.23.解:(1)∵△OPE的内心为M,∴∠MOP=∠MOC,∠MPO=∠MPE,∴∠PMO=180°﹣∠MPO﹣∠MOP=180°﹣(∠EOP+∠OPE),∵PE⊥OC,即∠PEO=90°,∴∠PMO=180°﹣(∠EOP+∠OPE)=180°﹣(180°﹣90°)=135°,(2)如图,∵OP=OC,OM=OM,而∠MOP=∠MOC,∴△OPM≌△OCM,∴∠CMO=∠PMO=135°,所以点M在以OC为弦,并且所对的圆周角为135°的两段劣弧上(和);点M在扇形BOC内时,过C、M、O三点作⊙O′,连O′C,O′O,在优弧CO取点D,连DC,DO,∵∠CMO=135°,∴∠CDO=180°﹣135°=45°,∴∠CO′O=90°,而OA=2cm,∴O′O=OC=×2=,∴弧OMC的长==π(cm),同理:点M在扇形AOC内时,同①的方法得,弧ONC的长为πcm,所以内心M所经过的路径长为2×π=πcm.24.解:(1)∵四边形ABCD和四边形EFCG是正方形,∴CD=CB,CG=CF,∠BCD=∠FCG=90°,∵∠DCG=90°﹣∠BCG,∠BCF=90°﹣∠BCG,∴∠DCG=∠BCF;(2)BF+BG=AB,理由:在Rt△CDG和△CBF中,,∴△CDG≌CBF(SAS),∴DG=BF,在Rt△ABD中,AD=AB,∴BD=AB,∵BD=DG+BG=BF+BG,∴BF+BG=AB;(3)∵BD是正方形ABCD的对角线,∴∠CBD=∠CDB=45°,由(2)知,△CDG≌CBF(SAS),∴DG=BF,∠CDG=∠CBF=45°,∴∠DBF=∠CBD+∠CBF=90°,∴∠FBT=90°,∵FT∥CB,∴∠BTF=∠CBD=45°,∴∠BFT=45°=∠BTF,∴BF=BT,∴DG=BT,∴GT=BG+BT=BG+DG=BD=AB=a.25.解:(1)当x=2时,y=x+2=2+2=4,∴点A坐标为(2,4),则k=2×4=8,∴双曲线C1的函数解析式为y=;(2)①点P′在双曲线C2:y=﹣上运动,设P (m ,) (m >0),如图,过点P 作PC ⊥x 轴于点C ,过点P ′作P ′D ⊥y 轴于点D ,则∠PCO =∠P ′DO =∠POP ′=90°,∴∠POC =∠P ′OD ,又∵OP =OP ′,∴△OPC ≌△OP ′D (AAS ),∴OD =OC =m ,P ′D =PC =,∴P ′(m ,﹣),则点P ′在双曲线C 2:y =﹣上运动.②设P (n ,),如图2,过点A 作AE ⊥y 轴于点E ,作PF ⊥x 轴于点F ,延长EA 、FP 交于点M ,则四边形OEMF 是矩形,M (n ,4),∵A (2,4),∴AM =n ﹣2,PM =4﹣,∵S △AOP =S 矩形OEMP ﹣S △AOE ﹣S △POF ﹣S △AMP , ∴=4n ﹣4﹣4﹣(n ﹣2)(4﹣),整理,得:3n2﹣16n﹣12=0,解得n=6或n=﹣(舍),当n=6时,=,∴点P(6,).故答案为:(6,).。
Passage 1A very rich man Peter lost his sight.The (1)told him that he could bring his sight back by doing a cornea (角膜)transplant operation.Peter(2) a lot of money for the cornea,but day after day,nobody came for that.One day,he took a walk in the park.He raised his head to (3)the long﹣awaited sunshine.However,he saw nothing but darkness.Just as Peter started feeling (4),someone suddenly ran into him."Don't you have eyes?Don't you see who you hit! I'm the millionaire Peter!" Peter said(5).The answer was from a little boy,"I'm sorry,sir.I didn't notice."Peter asked,"Is the (6)big today?" The boy answered happily,"Yes,it is pretty big and bright!" Peter smiled.He thought he could feel the sun again.He asked,"Is the park (7)?""Yes,very! The grass is green and the flowers are pretty.The(8)are so lovely and some birds are singing in them."While he was listening,Peter began to envy that boy.Suddenly,he(9),"God! How I envy this boy! It's unfair! Why not give me good sight?"You are wrong!" a woman said to Peter."My son is (10)just like you.He could only tell you so much because that's all I told him!" Tears suddenly filled Peter's eyes.Since then,the city charity has got a lot of money every year.It is from a man named Peter.(1)A.teacher B.doctor C.policeman D.driver(2)A.wasted B.paid C.offered D.gave(3)A.enjoy B.find C.face D.watch(4)A.nervous B.bored C.tired D.sad(5)A.softly B.coldly C.proudly D.angrily(6)A.wind B.sun C.cloud D.moon(7)A.beautiful B.different C.famous D.clean(8)A.kites B.rivers C.stones D.trees(9)A.understood B.cried C.asked D.smiled(10)A.deaf B.rich C.blind D.normalPassage 2It does not always come easy to discover oneself.From a young age,I had a strong sense of who I was to become,(1)an accident made me redefine (重审)myself.To me,skating was above all.There was(2)in this world that filled my heart with such joy.I spent twenty﹣four hours a week practicing my(3).Having no social life or interests but skating,my devotion(挚爱)brought me first place medals in nearly every(4).Unfortunately,in one show,I fell down and hurt myself(5).After several X﹣raysand MRI(磁共振)scans,the(6)told me that I couldn't return to my sport any more.The pain in my back was hard to bear,and even the(7)daily tasks became difficult.As my passion(激情)was(8),I had little sense of who I was to become.After eight months of suffering,something had to(9).Instead of wasting my days sitting around painfully,I began to put my(10)into local community service projects.By volunteering (11) a swimming teacher and summer reading assistant for kids,I got an idea of who I(12)_to become.After a few months,I devoted time to my interest in the arts.Little by Little,I (13)out of the shadow(阴影)and rebuilt my confidence.Sometimes,some(14)rocks block (阻碍)our way.We can choose to stay behind or try to climb over.My accident was a rock that(15)to stop me from reaching success.Today I'm a very confident and optimistic person.(1)A.and B.but C.or D.so(2)A.everything B.something C.nothing D.anything(3)A.skills B.behaviors C.thoughts D.habits(4)A.meeting B.party C.concert D.competition(5)A.quickly B.softly C.badly D.slowly(6)A.waiter B.doctor C.teacher D.policeman(7)A.useful B.basic C.proper D.busy(8)A.found out B.brought back C.waken up D.taken away(9)A.change B.remain C.leave D.arrive(10)A.energy B.duty C.wealth D.spirit(11)A.with B.for C.as D.to(12)A.wanted B.started C.promised D.lived(13)A.ran B.jumped C.stood D.stepped(14)A.small B.large C.ugly D.round(15)A.managed B.helped C.failed D.continuedPassage 3My father used to work in the fire prevention industry.He saw many terrible situations at the scene of the fire.And he attended Disaster Conferences.That was quite(1)for a father.As a result,as children,we used to have fire drills at home.My father would call us to a room.Whatever we were doing,we would go to the room (2)_and stand in front of my father."OK," he would say and point in one direction or another,"the fire is OUT THERE.How would you get out of here?"If we knew,we would answer him with what he had taught us before."Open the window and climb out!""But,what will you do if the window is(3)?""Break the window?""What with?What would you use in the sitting room to break the window?And once you've broken the window,how would you make it (4)to climb out?What would you put over the broken glass?In the sitting room,we would use the cushions off the sofa and armchairs to cover any broken glass.Upstairs,he taught us how to climb out of a bedroom window:throw out as many soft things to land on,such as pillows,blankets,quilts and even teddy bears,and then climb out and lower ourselves down to make the(5)to the ground as short as possible.Besides,we should put wet towels at the bottom of the door to prevent smoke from coming in.Whenever we moved house,he would (6)the advice accordingly(相应地).It made us aware of the risk of fire.If we can pay more attention to fire risk in our daily life,there will be fewer tragedies.(1)A)unusual B)important C)strange D)perfect(2)A)in this way B)with great care C)at once D)all the way (3)A)stuck B )broken C)open D )clean(4)A)comfortable B)pleasant C)safe D)easy(5)A)road B)distance C)weight D)rope(6)A)discover B)take C)provide D)changePassage 4The Chinese used the abacus as early as the 2nd century BC,but now are welcoming"machine brains"to educate the young in this modern age.For the young,e﹣learning seems so(1.Zhu Xufei,12,uses her parents' mobile phone to study English every day on her way to school and back home.Through an app,she can listen to and repeat back words and sentences in English.The app even tells the difference between her speech and proper pronunciation,and then(2provides the score.The mother of 12﹣year﹣old Zhu said,"The apps have enabled her to learn and practice spoken English anytime,anywhere,"she says."The apps also have been designed to use games to encourage learning."It's very popular nowadays,especially with parents.WeChat accounts of parents post progress reports every day on(3their children are doing.For example,"Day 30:My son Thomas has learned 99English words on Talking Pets."It's not only children using mobile devices(设备)to learn new things.Many Metro or bus passengers can be seen with earplugs turned into app courses,like business management or the driving test."I don't have to(4books around and turn pages on crowded buses,"an office lady says."With just a touch of the screen on my smartphone,I can do practice tests whenever I have time.It also records my(5and makes it easier for me to review them."E﹣learning has been welcomed among education services.Zheng Lili,owner of an English training school,says the learning apps help(6better monitor the performances of students.We believe that education should be‘whole﹣person'development and such devices are just support tools.1 A.strange B.difficult C.natural D.horrible2 A.immediately B.gently C.nearly D.secretly3 A.whether B.where C.why D.how4 A.borrow B.carry C.return D.deliver5 A.mistakes B.jobs C.photos D.interest6 A.bosses B.neighbours C.friends D.teachersPassage 5John and Mary had two lovely children.Once they were asked to go on a business trip.So they found a babysitter to take care(1)the children.A week later,as they drove into their hometown,they noticed smoke and went to see(2).A house was on fire! Mary said,"Well,the house isn't(3).Let's go."But John kept driving(4),"The house belongs to Fred." "It has nothing to do with us,let's go." said Mary.But John drove up.A woman(5)in the street,"My children! Help! Help!" John asked her (6)him where her children were."In(7)bathroom," cried the woman.(8)Mary didn't agree,John hurried for the bathroom(9)was full of smoke and heat.He soon found two children.As he left he could hear some other sound like crying.He (10)sent the two children to a safe place.But he(11)two more children were still inside.Mary shouted,"Don't go back! That house(12)down in any second!"John went back by(13)his way down into the room.It seemed a century had passed before he found both the children(14)the return way.As he walked up the endless steps,the thought went through his mind that there was(15)strangely familiar about the little bodies,and at last when they came out,he found that he had just saved his own children!The babysitter had left them at this house while she did some shopping.1.A.of B.for C.on D.about 2.A.what is it B.what was it C.what was it D.what it was 3.A.we B.us C.our D.ours 4.A.close B.cried C.closest D.has cried 5.A.cries B.showing C.was crying D.shows 6.A.to show B.for C.showed D.about 7.A. a B.an C.the D.不填8.A.But B.Although C.Since D.Because9.A.who B.why C.when D.which 10.A.quick B.quickly C.quickness D.quicken 11.A.tells B.told C.was told D.has told 12.A.falls B.fell C.will fall D.was falling 13.A.feel B.feels C.to feel D.feeling 14.A.but B.and C.so D.or 15.A.something B.anything C.everything D.nothingPassage1【解答】BCADD BADBCPassage2【解答】BCADC BBDAA CADBC Passage3【解答】A C A CBDPassage4【解答】CADBADPassage5【解答】ADDAC ACBDB CCDDA。
部编版四年级语文下册期末模拟冲刺卷(2)(有答案解析)班级姓名成绩一、用“\”划掉下面每组词语中加点字的错误读音并改正在横线上。
1拥挤. jǐ绽.开dìng 鸟巢. cháo __________2膝.盖qī思潮. c háo 余晖. huī__________3集.中jí曝.晒bào 徜.徉cháng __________4胆怯. qù赤.道chì炫.耀xuàn __________二、下面书写中完全正确的一组是()。
A.屋檐照例早餐生机勃勃欣喜苦狂B. 推测仍旧笨重一丝不荀无忧无虑C. 阵雨扫荡逼近瑟瑟发抖天高地阔D. 穿越温顺狂吠惊慌失措点晴之笔三、词语综合训练。
1.“奢侈.、啄.食、窥伺.、哺.育”这四个词语中,加点字的注音完全正确的一项是( )。
A.chǐ zhuó cì pǔB.cǐ zuó sì bǔC.chǐ zhuó sì bǔ2.加偏旁组新字。
肖 ( )丽陡( ) 树( ) ( )等3.同音字组词。
jì成( ) ( )然邮( ) 世( )4.下面各组句子中加点字词的意思相同的一项是( )A.小猫是那么生气..。
..勃勃,天真可爱!他那样做我很生气B.猫的性格实在有些古怪.。
他不是故意的,请不要责怪.他。
C.它非.把老鼠等出来不可!如果你非.要去,我也不拦你。
四、读拼音,写字词。
shùn jiān fēi xiánɡzhèn hàn pínɡzhànɡ()()()()niǎo shòu wéi kànɡsuǒmén jìrán()()()()五、下列加点词语运用不正确的一项是( )。
A.他们手挽着手,走进了那华丽..的帐篷。
初三冲刺卷子试题及答案一、选择题(每题2分,共20分)1. 下列词语中加点字的读音完全相同的一组是()A. 筵席瞻仰恹恹欲睡偃旗息鼓B. 蹊跷祈祷锲而不舍黯淡无光C. 矍铄攫取掬水月在手掬诚相待D. 剽悍骠勇剽窃缥缈答案:B2. 下列词语中没有错别字的一组是()A. 涣散蹒跚缭亮怏怏不乐B. 恣意恣睢缱绻桎梏C. 蹉跎蹉跌蹉跎岁月蹉跌不前D. 缭绕缭乱缭草缭花答案:B3. 下列句子中加点成语使用正确的一项是()A. 他虽然犯了错误,但已经改过自新,我们不要对他求全责备。
B. 他这个人做事总是独断专行,从不听取别人的意见。
C. 他虽然年纪轻轻,但已经著作等身,真是年轻有为。
D. 他这个人总是妄自菲薄,不思进取。
答案:C4. 下列句子中没有语病的一项是()A. 通过这次活动,使我们对环保有了更深的认识。
B. 他虽然学习成绩优异,但是工作能力也很强。
C. 我们一定要防止类似事件不再发生。
D. 他不但学习成绩优异,而且工作能力也很强。
答案:D5. 下列句子中关联词语使用正确的一项是()A. 他虽然年轻,但是经验丰富。
B. 他不但年轻,而且经验丰富。
C. 他虽然年轻,却经验丰富。
D. 他不但年轻,所以经验丰富。
答案:B6. 下列句子中加点词语解释正确的一项是()A. 他这个人总是妄自菲薄(轻视)。
B. 他这个人总是妄自尊大(自大)。
C. 他这个人总是妄自菲薄(自大)。
D. 他这个人总是妄自尊大(轻视)。
答案:A7. 下列句子中加点词语使用正确的一项是()。
A. 他这个人总是妄自菲薄,不思进取。
B. 他这个人总是妄自尊大,目中无人。
C. 他这个人总是妄自菲薄,目中无人。
D. 他这个人总是妄自尊大,不思进取。
答案:B8. 下列句子中加点成语使用正确的一项是()。
A. 他这个人总是妄自菲薄,不思进取。
B. 他这个人总是妄自尊大,目中无人。
C. 他这个人总是妄自菲薄,目中无人。
D. 他这个人总是妄自尊大,不思进取。
期中满分冲刺必刷卷(二)参考答案与试题解析一.用心思考,正确填空(共10小题)1.(2019春•绍兴期末)2()=6()4150.430()÷===.【分析】把0.4化成分数并化简是25;根据分数的基本性质分子、分母都乘2就是410;都乘6就是1230;根据分数与除法关系2255=÷,再根据商不变的性质被除数、除数都乘3就是315÷.【解答】解:21246150.4 53010=÷===.故答案为:5,6,18,10.【点评】解答此题的关键是0.4,根据小数、分数、除法间的关系及分数的基本性质、商不变的性质即可解答.2.(2019春•方城县期中)在横线里填上合适的单位.一个粉笔盒的体积接近1一个汽车油箱的容积约是50一个挂衣柜的体积约是4一瓶眼药水的体积约是45【分析】根据生活经验,对体积单位、容积单位和数据的大小认识,可知:计量一个粉笔盒的体积用立方分米做单位,计量一个汽车油箱的容积用升做单位;计量一个挂衣柜的体积用立方米做单位;计量一瓶眼药水的体积用毫升做单位.【解答】解:一个粉笔盒的体积接近1 立方分米一个汽车油箱的容积约是50 升一个挂衣柜的体积约是4 立方米一瓶眼药水的体积约是45 毫升故答案为:立方分米,升,立方米,毫升.【点评】此题考查根据情景选择合适的计量单位,要注意联系生活实际、计量单位和数据的大小,灵活的选择.3.(2019秋•大名县期中)24的因数是1、2、3、4、6、8、12、24,其中质数是.分解质因数24=.【分析】找一个数的因数,可以一对一对的找,把24写成两个数的乘积,那么每一个乘积中的因数都是24的因数,然后从小到大依次写出即可,据此找出24的因数有哪些;然后根据质数的特征:只有1和它本身两个因数,判断出质数有哪些即可;分解质因数就是把一个合数写成几个质数的连乘积形式,一般先从简单的质数试着分解.【解答】解:因为241242123846=⨯=⨯=⨯=⨯,所以24的因数有:1、2、3、4、6、8、12、24,其中2、3是质数; 242223=⨯⨯⨯.故答案为:1、2、3、4、6、8、12、24,2、3,2223⨯⨯⨯.【点评】此题主要考查了找一个数的因数的方法,分解质因数以及质数、合数的判断,要熟练掌握. 4.(2019春•黄冈期末)在两位数中,是3的倍数的最大偶数是 96 ,同时是3和5的倍数的最大奇数是 .【分析】根据3的倍数的特征,各个数位上的数字之和是3的倍数,这个数就是3的倍数;5的倍数特征是:个位上是0或5的数是5的倍数;由此解答即可.【解答】解:在两位数中,是3的倍数的最大偶数是 96,同时是3和5的倍数的最大奇数是75. 故答案为:96,75.【点评】此题主要根据3、5的倍数的特征和公倍数的意义解答.5.(2019秋•会宁县期末)2113的分数单位是 113,它有 个这样的分数单位,再加上 个这样的分数单位就等于最小的质数.【分析】把2113化成假分数是1513,表示把单位“1”平均分成13份,它有这样的15份.根据分数单位的意义,把单位“1”平均分成若干份,表示其中1份的数叫分数单位.因此,这个分数的分数单位是113,它有15个这样的分数单位.最小的质数是2,26213=,即26个这样的分数单位是最小的质数,需要再添上261511-=个这个样的分数单位.【解答】解:21511313=2113的分数单位是113,它有 15个这样的分数单位 最小的质数是2,26213=,即26个这样的分数单位是最小的质数,需要再添上261511-=个这个样的分数单位. 故答案为:113,15,11. 【点评】分数(nm m、n 均为不等于0的自然数),1m 就是这个分数的分数单位,n 就是这样分数单位的个数.6.(2019春•方城县期中)要使514□是2的倍数,□里最大填 8 ;若这个数含有因数3,□里最小填 ;若这个数既是2的倍数,又含有因数5,□里只能填 . 【分析】能被2整除的数的特征,个位上是0、2、4、6、8的数;能被3整除的数的特征,各个数位的数字加起来是3的倍数,51410++=,□里可以填2、5、8;根据2、5倍数的特征可知:这个两位数的个位上必需是0,因为个位上是0的数同时是2和5的倍数,据此解答.【解答】解:根据分析可知要使514□是2的倍数,□里最大填:8;若这个数含有因数3,□里最小填:2;若这个数既是2的倍数,又含有因数5,□里只能填:0.故答案为:8,2,0.【点评】解答此题的关键是灵活掌握能被2、3、5整除的数的特征.7.(2019•兰州模拟)如图是一个正方体的展开图,若在正方体的各面填上数,使其相对面两数之和为10,现在有三个面分别为4,2,1,则另三个面上的数字为:A=8,B=.【分析】如图,是正方体展开图的“222”结构,把它折成正方体后,A面与2面相对,B面与4面相对,C面与1面相对,相对面两数之和为10,据此即可求出A、B.【解答】解:如图,折成正方体后,A面与2面相对,B面与4面相对,因此,1028B=-=;A=-=,1046故答案为:8,6.【点评】本题是考查正方体展开图,关键是弄清哪两个面相对.8.(2019春•江城区期末)一个正方体的棱长总和是36dm,它的表面积是54平方分米,体积是.【分析】正方体的棱长总和=棱长12⨯,已知正方体的棱长总和是36分米,那么正方体的棱长是36123÷=分米,根据正方体的表面积公式:2=,体积公式:3S a6=,把数据分别代入公式解答.V a【解答】解:36123÷=(分米)⨯⨯=(平方分米)33654⨯⨯=(立方分米)33327答:它的表面积是54平方分米,体积是27立方分米.故答案为:54平方分米、27立方分米.【点评】此题主要考查正方体的表面积公式、体积公式的灵活运用,关键是熟记公式.9.(2019秋•江都区校级期末)有一个长12厘米,宽8厘米,高4厘米的长方体,把高增加3厘米,则体积增加 288 立方厘米,表面积增加 平方厘米.【分析】根据长方体的体积公式:V abh =,表面积公式:()2S ab ah bh =++⨯,高增加3米,体积增加部分是以原来的长、宽为长、宽高是3厘米的长方体的体积,即(1283)⨯⨯立方厘米,表面积增加部分是长12厘米、宽8厘米,高3厘米的长方体的4个侧面的面积,即(1232832)⨯⨯+⨯⨯平方厘米. 【解答】解:1283288⨯⨯=(立方厘米) 1232832⨯⨯+⨯⨯ 7248=+120=(平方厘米)答:体积增加288立方厘米,表面积增加120平方厘米. 故答案为:288、120.【点评】此题主要考查长方体的体积公式、表面积公式的灵活运用,关键是熟记公式.10.(2019春•方城县期中)聪聪用31cm 的小正方体摆成一个长方体,从正面、左面和上面看到的分别如下图所示的图形.这个长方体的表面积是 52 2cm ,体积是 3cm .【分析】观察图形可知,这个长方体是长4cm 、宽3cm 、高2cm 的长方体;根据长方体的表面积公式:2()S ab ah bh =++,体积公式:V abh =即可得解.【解答】解:观察图形可知,这个长方体是长4cm 、宽3cm 、高2cm 的长方体, (434232)2⨯+⨯+⨯⨯ (1286)2=++⨯ 262=⨯252()cm = 432⨯⨯122=⨯324()cm =答:这个长方体的表面积是252cm ,体积是324cm . 故答案为:52;24.【点评】此题考查了从不同的方向观察物体和几何体,锻炼了学生的空间想象力和抽象思维能力.二.仔细推敲,公正判断(共5小题)11.(2019秋•天等县期中)因为4312⨯=,所以4,3是因数,12是倍数.⨯( )【分析】由因数和倍数的意义可知,当(a b c a÷=、b、c为非0自然数),我们说a是b的倍数,b是a的因数.由此可见,因数和倍数是相互依存的,不是单独说哪个数是因数,哪个数是倍数.所以本题不能说12是倍数,3是因数.由此可求解.【解答】解:因数和倍数是相互依存的,不是单独说哪个数是因数,哪个数是倍数.所以本题不能说12是倍数,3是因数;应该为12是3的倍数,3是12的因数.故答案为:⨯.【点评】本题主要是考查因数和倍数的意义,因数和倍数是相互依存的,不要忽略这一点.12.(2019秋•德惠市期中)最小的质数和最小的合数都是奇数.⨯( )【分析】根据奇数、偶数、质数、合数的意义,在自然数中,不是2的倍数的数叫做奇数;在自然数中,是2的倍数的数叫做偶数;一个自然数,然后只有1和它本身两个因数,这样的数叫做质数;一个自然数,如果除了1和它本身还有别的因数,这样的数叫做合数.1既不是质数也不是合数.据此解答即可.【解答】解:最小的质数是2,2是偶数,最小的合数是4,4也是偶数,故原题说法错误;故答案为:⨯.【点评】此题考查的目的是理解掌握奇数与偶数、质数与合数的意义,明确:奇数与质数的区别、偶数与合数的区别.13.(2019春•简阳市期中)长方体的面中可能有正方形,正方体的面中不可能有长方形.√.( )【分析】长方体的面中可能有正方形,正方体的每个面都是正方形,所以正方体的面中不可能有长方形,据此解答即可.【解答】解:长方体的面中可能有正方形,正方体的每个面都是正方形,所以正方体的面中不可能有长方形,所以本题说法正确.故答案为:√.【点评】本题考查的是长方体和正方体特征的运用.14.(2019秋•龙州县期末)710的分子乘2,分母加上10后,分数值不变.√.( )【分析】首先发现分子之间的变化,分子乘2,扩大了2倍;分母加上10后,变为20,20102=⨯,分母扩大了2倍;再根据分数的基本性质即可作出判断.【解答】解:原分数分子乘2,扩大了2倍;原分数分母是10,现在分数的分母是101020+=,扩大2倍,分子分母扩大的倍数相同,分数值不变. 故答案为:√.【点评】此题主要利用分数的基本性质解答问题,先观察分子或分母之间的变化,发现规律,再进一步通过计算解答问题.15.(2019秋•隆昌市期末)把一根绳子对折以后再对折,量得长度是原来的14. √ ( ) 【分析】把这根绳子的长度看作单位“1”,把它对折后被平均分成2份,每份是原来的12;再对折后被平均分成4份,每份是原来的14,由此判断. 【解答】解:把一根绳子对折以后再对折,这根绳子被平均分成4份,量得长度是原来的14原题说法正确. 故答案为:√.【点评】此题是考查分数的意义.把单位“1”平均分成若干份,用分数表示,分母是分成的份数,分子是要表示的份数.关键明白这根绳子对折再对折后被平均分成多少份. 三.认真审题,精挑细选(共5小题)16.(2019秋•中山区期末)用5个小正方体搭一个立体图形,从正面看到的形状是,从上面看到的形状是,这个立体图形是( )A .B .C .D .【分析】根据从上面和正面看到的图形,逐项分析即可解答问题. 【解答】解:根据题干分析可得:A .从正面看到的图形是下层3个正方形,上层1个正方形靠最左边,不符合题意;B .从正面看到的图形是2层:下层2个正方形,上层1个靠左边;不符合题意;C .从正面看到的是2层:下层2个正方形,上层1个靠左边,不符合题意;D .从正面看到的图形是2层:下层2个正方形,上层1个靠右边,符合题意;从上面看到的图形是田字,符合题意; 故选:D .【点评】本题是考查从不同方向观察物体和几何体.意在训练学生的观察能力. 17.(2019秋•高平市期末)如果7x 是假分数,8x是真分数,那么x 的值是( ) A .7B .8C .6【分析】要使7x 是假分数,则x 为等于或大于7的任意一个整数;要使8x是真分数,x 只能是1、2、3、4、5、6、7共7个整数,由此根据题意解答问题. 【解答】解:要使7x是假分数,x 大于或等于7; 要使8x是真分数,x 小于或等于7; 所以x 只能等于7. 故选:A .【点评】此题主要利用真分数与假分数的意义进行解答即可. 18.(2019•湘潭模拟)正方体的棱长扩大3倍,体积扩大( ) A .3倍B .9倍C .18D .27倍【分析】设原正方体的棱长为a ,则扩大3倍后的棱长为3a ,分别求出扩大前后的体积,用扩大后的体积除以原来的体积,就是体积扩大的倍数.【解答】解:设原正方体的棱长为a ,则扩大3倍后的棱长为3a , 原正方体的体积:3a a a a ⨯⨯=;扩大后的正方体的体积:333327a a a a ⨯⨯=, 体积扩大:332727a a ÷=倍; 答:体积扩大27倍. 故选:D .【点评】此题主要考查正方体体积公式的灵活应用.19.(2019秋•双桥区期末)下面各数中,同时是2,3,5的倍数的数有( ) A .65B .130C .240D .100【分析】同时是2、3和5的倍数的数要满足个位上是0,而且各个数位上的数的和是3的倍数;据此逐项分析后选择.【解答】解:A 、65不是2的倍数,A 不符合题意;B 、130不是3的倍数,B 不符合题意;C 、240同时是2,3,5的倍数,C 符合题意;D 、100不是3的倍数,不符合题意.故选:C .【点评】本题主要考查同时是2、3和5的倍数的特征,熟悉特征并灵活运用即可.20.(2019秋•贵阳期末)一个长方体,若将长增加3厘米,则体积增加60立方厘米;若将宽增加3厘米,则体积增加120立方厘米;若将高增加3厘米,则体积增加150立方厘米.原长方体的表面积是( )平方厘米. A .110B .220C .330【分析】根据长方体的体积公式:V abh =,那么(150350)ab V h =÷÷=,(120340)ah V b =÷÷=,(60320)bh V a =÷÷=,据此可以求出ab 、ah 、bh ,然后根据长方体的表面积公式:()2S ab ah bh =++⨯,把数据代入公式解答.【解答】解:(60312031503)2÷+÷+÷⨯ (204050)2=++⨯ 1102=⨯220=(平方厘米)答:原来长方体的表面积是220平方厘米. 故选:B .【点评】此题主要考查长方体的体积公式、表面积公式的灵活运用,关键是熟记公式. 四.按要求完成下面各题(共4小题)21.(2019秋•临漳县期末)通分比较下列各分数的大小. 59和35 56、1924和13116【分析】根据分数的基本性质,把几个异分母分数化成与原来分数相等的同分母的分数的过程,叫做通分.据此将各组中的分数通分后化为同分母的分数比较大小即可. 【解答】解:59和35因为525945= 327545= 25274545<所以5395<56、1924和13116因为540648= 19382448=1339111648= 3840391484848<< 所以19513124616<< 【点评】比较异分母分数大小的时候,一般要先将异分母分数化成同分母分数后,再进行比较. 22.(2019春•邗江区校级月考)把下面的分数约分,约分结果是假分数的化成整数或带分数. 46483238953913【分析】根据约分的方法,把分数的分子和分母分别除以它们的最大公因数,化成分子和分母只有公因数1的分数.再根据假分数化成带分数的方法进行解答即可. 【解答】解:44226623÷==÷ 48481631132321622÷===÷ 38381929595195÷==÷ 3939133131313÷==÷ 【点评】此题考查的目的是理解掌握约分的方法和步骤,以及假分数化成带分数的方法. 23.(2019春•江苏校级月考)从下面选出三张数字卡片,组成一个三位数.(每题写两个) 0 5 6 1组成的数是2的倍数: 160、156 组成的数既是偶数,又是5的倍数: 组成的数既是奇数,又是3的倍数: .【分析】一个整数能够被另一整数整除,这个整数就是另一整数的倍数.一个数的个位数如是偶数,则这个数一定能被2整数.如160,156;组成的数既是偶数,又是5的倍数,即这个数既能被2整除,也能被5整除,则这个数的个位一定为0,如150、560;组成的数既是奇数,又是3的倍数,则这个数的个位是奇数,又能被3整除的数的各位数字的和一定能被3整数,如561、165. 【解答】解:组成的数是2的倍数:160、156; 组成的数既是偶数,又是5的倍数:150、560; 组成的数既是奇数,又是3的倍数:561,165. 故答案为:160、156;150、560;561,165.【点评】明确能被2、3、5整除数的特征是完成本题的关键.24.(2010秋•海安县校级期中)把5个同样大小的正方体分别栟成下面的物体.①从 左 面看这三个物体,看到的形状都是.②从 面看这三个物体,看到的形状各不相同. ③从 面看这三个物体,看到的都是【分析】观察图形可知,这三个物体,从左面看到的形状都是;从正面看这三个物体,看到的形状分别是,形状各不相同;从上面看这三个物体,看到的都是,据此解答即可.【解答】解:由分析可知:①从左面看这三个物体,看到的形状都是;②从正面看这三个物体,看到的形状各不相同; ③从上面看这三个物体,看到的都是.故答案为:①左;②正;③上.【点评】本题是考查从不同方向观察物体和几何图形,培养学生的观察能力. 五.看清题目,认真计算(共2小题)25.(2019秋•徐州月考)看图求它们的棱长总和、表面积与体积.(单位:厘米)【分析】(1)根据长方体的特征,长方体的12条棱分三组(长、宽、高),每组4条,长度相等,用长方体长、宽、高之和乘4就是它的棱长总和;根据长方体的表面积计算公式“2()S ab ah bh =++”,长方体的体积计算公式“V abh =”即可求出这个长方体的表面积、体积.(2)根据正方体的特征,正方体的12条棱长度相等,即可求出这个正方体的棱长总和;根据正方体的表面积计算公式“26S a =”及体积计算公式“3V a =”即可求出这个正方体的表面积、体积. 【解答】解:(1)(1086)4++⨯244=⨯96=(厘米)2(10810686)⨯⨯+⨯+⨯=⨯++2(806048)=⨯2188=(平方厘米)376⨯⨯1086=⨯806480=(立方厘米)答:这个长方体的棱长总和是96厘米,表面积是375平方厘米,体积是480立方厘米.(2)51260⨯=(厘米)556⨯⨯=⨯256=(平方厘米)150555⨯⨯=⨯255=(立方厘米)125答:这个正方体的棱长总和是60厘米,表面积是150平方厘米,体积是125立方厘米.【点评】解答此题的关键一是记住长方体、正方体的特征;二记住相关计算公式并会运用.26.下面是一个无盖长方体纸盒的表面展开图,请计算出纸盒的面积和体积.【分析】根据长方体的表面积公式:()2s ab ah bh=++⨯,已知纸盒无盖,所以只求它的一个底面和4个侧面的总面积,体积公式:v abh=,把数据分别代入公式解答.【解答】解:高:(106)2-÷=÷42=(厘米),2长:12210-=(厘米),(10610262)106⨯+⨯+⨯-⨯(602012)260=++⨯-92260=⨯-18460=-124=(平方厘米),1062120⨯⨯=(立方厘米),答:这个长方体纸盒的面积是124平方厘米,体积是120立方厘米.【点评】此题主要考查长方体的表面积公式、体积公式的灵活运用,关键是熟记公式,重点是求出高和长.六.走进生活,解决问题(共6小题)27.(2019秋•靖州县期末)丽丽读一本书,已读了32页,还剩48页没有读.(1)已读了全书的几分之几?(2)还剩全书的几分之几没有读?【分析】(1)用加法求出一共多少页,再用已读的页数除以总页数就是已读了全书的几分之几.(2)把总页数看作单位“1”,用单位“1”减去已读了全书的几分之几就是还剩全书的几分之几没有读.【解答】解:(1)32(3248)÷+3280=÷25=答:已读了全书的25.(2)23 155 -=答:还剩全书的35没有读.【点评】本题考查了分数除法的意义和分数减法的意义.28.(2019春•长寿区期末)一筐苹果,每人7个剩6个,每人8个也剩6个,这筐苹果至少有多少个?【分析】如果苹果的数量少6个,那么平均分给每人7个、8个人就不会有余数,所以苹果的数量是8和7的最小公倍数多6,由此进一步得出答案即可.【解答】解:8和7互质,所以8和7的最小公倍数是7856⨯=56662+=(个)答:这筐苹果至少有62个.【点评】此题考查最小公倍数的实际运用,注意问题的转化方法.关键是得出苹果的数量是7和8的最小公倍数多6.29.(2019春•英山县期末)有一张长方形纸,长72厘米、宽48厘米,要把它裁成同样大小的正方形且不许有剩余,最少可以裁几张?【分析】根据题意,裁成的正方形边长最大是多少,是求72和48的最大公因数,求至少可以裁成多少个这样的正方形,用这张纸的面积除以正方形面积.由此解答即可.【解答】解:7222233=⨯⨯⨯⨯,=⨯⨯⨯⨯,482222372和48的最大公因数是222324⨯⨯⨯=,⨯÷⨯7248(2424)=÷3456576=(张)6答:至少可以裁6张.【点评】此题主要考查求两个数的最大公因数,能够根据求最大公因数的方法解决有关的实际问题.30.(2019春•庆云县期末)用240厘米的铁丝做一个最大的正方体框架,再用纸板将6个面包起来,至少用纸板多少平方厘米?纸盒的体积是多少立方厘米?【分析】根据正方体的特征,12条棱的长度都相等,6个面的面积都相等.用一根36厘米长的铁丝,做一个正方体框架.即棱长总和是36厘米,首先求出它的棱长,再利用表面积和体积公式解答.【解答】解:2401220÷=(厘米);⨯⨯=(平方厘米);2020624002020208000⨯⨯=(立方厘米);答:至少用纸板2400平方厘米,纸盒的体积是8000立方厘米.【点评】此题主要考查正方体的特征和体积、表面积的计算方法,要注意12条棱的长度总和是240厘米.31.(2019春•博白县校级期中)把3个棱长相等正方体拼成一个长方体后,表面积减少了100平方厘米,这个长方体的体积是多少立方厘米?【分析】3个正方体拼成一个长方体后,相当于减少了4个正方体的面,根据表面积就减少了100平方厘米,可求出正方体每个面的面积,进而求出正方体的棱长,然后再求出每个正方体的体积,拼成后的长方体的体积是正方体体积的3倍,即可求出这个长方体的体积.【解答】解:100425÷=(平方厘米),因为25平方厘米5=厘米5⨯厘米,所以正方体的棱长是5厘米,5553⨯⨯⨯=⨯1253=(立方厘米).375答:这个长方体的体积是375立方厘米.故答案为:54.【点评】本题是考查图形的切拼问题、长方体和正方体的体积.解答此题的关键是理解3个正方体拼成一个长方体后,减少了几个正方体的面.32.一只装有水的长方体水槽,底面积为80平方厘米,水深8厘米.现将一个底面积为16平方厘米的长方体铁块竖放在水中,仍有部分铁块露在外面,求现在的水深多少厘米?【分析】将长方体铁块竖放在水槽中,水的体积不变,水槽的底面积减去铁块的底面积就是水的底面积,依此求出现在水深.【解答】解:808(8016)⨯÷-=÷6406410=(厘米)答:现在的水深10厘米.【点评】解答此题的关键是理解求现在水的高度要用水的体积除以水的底面积.。
2021年江苏中考数学冲刺专题训练——专题2整式、因式分解一.选择题(共2小题)1.(2021•龙岗区模拟)如图,矩形ABCD的周长是10cm,以AB,AD为边向外作正方形ABEF和正方形ADGH,若正方形ABEF和ADGH的面积之和为17cm2,那么矩形ABCD 的面积是()A.3cm2B.4cm2C.5cm2D.6cm2 2.(2019•安徽)已知三个实数a,b,c满足a﹣2b+c=0,a+2b+c<0,则()A.b>0,b2﹣ac≤0B.b<0,b2﹣ac≤0C.b>0,b2﹣ac≥0D.b<0,b2﹣ac≥0二.填空题(共8小题)3.(2021春•鼓楼区期中)如图是A型卡片(边长为a的正方形)、B型卡片(长为a、宽为b的长方形)、C型卡片(边长为b的正方形).现有4张A卡片,11张B卡片,7张C 卡片,选用它们无缝隙、无重叠地拼正方形或长方形,下列说法正确的是.(只填序号)①可拼成边长为a+2b的正方形;②可拼成边长为2a+3b的正方形;③可拼成长、宽分别为2a+4b、2a+b的长方形;④用所有卡片可拼成一个大长方形.4.(2021春•南京月考)三种不同类型的地砖的长、宽如图所示,若现有A型地砖4块,B 型地砖4块,C型地砖2块,要拼成一个正方形,则应去掉1块地砖;这样的地砖拼法可以得到一个关于m,n的恒等式为.5.(2020秋•江汉区期末)将两张边长分别为6和5的正方形纸片按图1和图2的两种方式放置在长方形ABCD内,长方形ABCD内未被这两张正方形纸片覆盖的部分用阴影表示,设图1中的阴影面积为S1,图2中的阴影面积为S2,当AD﹣AB=3时,S2﹣S1的值是.6.(2020春•沭阳县期末)因式分解:2m2﹣4mn+2n2=.7.(2020•张家界)因式分解:x2﹣9=.8.(2020•浙江自主招生)若m2=n+2,n2=m+2(m≠n),则m3﹣2mn+n3的值为.9.(2019春•江宁区期中)已知a=12018+2017,b=12018+2018,c=12018+2019,则代数式a2+b2+c2﹣ab﹣bc﹣ca=.10.(2019•徐州二模)因式分解4x2﹣4=.三.解答题(共20小题)11.(2021春•南京期中)探究活动:(1)如图①,可以求出阴影部分的面积是(写成两数平方差的形式);(2)如图②,若将图①中阴影部分裁剪下来,重新拼成一个长方形,面积是(写成多项式乘法的形式);(3)比较图①,图②阴影部分的面积,可以得到公式.知识应用:运用你得到的公式解决以下问题:(4)计算:(Ⅰ)(a+b﹣2c)(a+b+2c);(Ⅱ)(2a+b﹣3c)(﹣2a+b+3c).12.(2021春•鼓楼区校级月考)阅读:若x满足(80﹣x)(x﹣60)=30,求(80﹣x)2+(x﹣60)2的值.解:设(80﹣x)=a,(x﹣60)=b,则(80﹣x)(x﹣60)=ab=,a+b=(80﹣x)+(x﹣60)=,所以(80﹣x)2+(x﹣60)2=a2+b2=(a+b)2﹣2ab=.请仿照上例解决下面的问题:(1)补全题目中横线处;(2)已知(30﹣x)(x﹣20)=﹣10,求(30﹣x)2+(x﹣20)2的值;(3)若x满足(2021﹣x)2+(2020﹣x)2=2019,求(2021﹣x)(x﹣2020)的值;(4)如图,正方形ABCD的边长为x,AE=10,CG=25,长方形EFGD的面积是400,四边形NGDH和MEDQ都是正方形,PQDH是长方形,求图中阴影部分的面积(结果必须是一个具体数值).13.(2021春•秦淮区校级期中)先化简,再求值:(3a﹣2b)(2a+3b)−12(3a+2b)2﹣a(32a﹣2b),其中|a+12|+|b+1|=0.14.(2021春•宜兴市期中)计算或化简:(1)﹣22+(23)﹣1+(π﹣3)0(2)a⋅a2⋅a3+(﹣2a3)2﹣a9÷(﹣a)3(3)(x+3)(x﹣3)﹣(x﹣2)2(4)(m+2n﹣3)(m﹣2n+3)15.(2021•滨湖区一模)(1)计算:|3−2|﹣(12)﹣2+2sin60°;(2)化简:(a+b)2﹣a(a+2b).16.(2021春•徐州期中)计算:(1)(﹣1)2021+(﹣2)0+(12)﹣3;(2)a•a3•a4﹣4a10÷a2+(﹣3a4)2;(3)(x+5)(x﹣3)﹣x(x+2);(4)20212﹣2020×2022.17.(2021春•鼓楼区校级月考)计算:(1)(﹣3a3)2÷a2;(2)(﹣2a)3﹣(﹣a)•(3a)2;(3)﹣22+30﹣(−12)﹣1;(4)(318)12×(825)11×(﹣2)3.18.(2021春•鼓楼区校级月考)计算:(1)(﹣3y)5÷(﹣3y)2;(2)2a2•4a4﹣(﹣3a2)3;(3)(π﹣3)0﹣(−12)﹣2+25×(﹣1)﹣2021;(4)x(x+y)﹣(2x+3y)2;(5)(3a﹣2b)(2b+3a)﹣(2a)2.19.(2021春•邗江区月考)规定两数a,b之间的一种运算,记作(a,b);如果a c=b,那么(a,b)=c.例如:因为23=8,所以(2,8)=3.(1)根据上述规定,填空:①(5,125)=,(﹣2,﹣32)=;②若( ,116)=−4,则x=.(2)若(4,5)=a,(4,6)=b,(4,30)=c,试说明下列等式成立的理由:a+b=c.20.(2021春•南京月考)计算:(1)|−2|+( −3)0−(13)−2+(−1)2021;(2)(﹣2×1012)×(﹣2×102)3÷(0.5×103)3;(3)(−12 2)×(23 2 −6 );(4)(a﹣2b+3c)×(a+2b﹣3c);(5)(﹣2m﹣3)2(3﹣2m)2;(6)4×1.632+6.52×6.74+6.742.(用乘法公式计算)21.(2021•滨湖区模拟)计算:(1)2﹣1﹣(﹣0.5)0−4;(2)(x﹣3)2+x(x﹣2)22.(2020秋•江都区期末)先化简,再求值:12x﹣2(x−13y2)+(−32 +13 2),其中x=﹣2,y=23.23.(2020秋•渑池县期末)乘法公式的探究及应用.(1)如图1,可以求出阴影部分的面积是(写成两数平方差的形式);(2)如图2,若将阴影部分裁剪下来,重新拼成一个长方形,它的宽是,长是,面积是.(写成多项式乘法的形式)(3)比较左、右两图的阴影部分面积,可以得到乘法公式.(用式子表达)(4)运用你所得到的公式,计算下列各题:①10.3×9.7②(2m+n﹣p)(2m﹣n+p)24.(2021春•秦淮区校级期中)因式分解:(1)25(a+b)2﹣9(a﹣b)2;(2)16ab2﹣6a3﹣4ab2;(3)(x2﹣4x)2+8(x2﹣4x)+16.25.(2021春•玄武区期中)把下列各式分解因式:(1)ax3﹣16ax;(2)(2x﹣3y)2﹣2x(2x﹣3y)+x2;(3)(m2+1)2﹣4m2.26.(2021春•吴江区期中)整式乘法与多项式因式分解是既有联系又有区别的两种变形.例如,a(b+c+d)=ab+ac+ad是单项式乘多项式的法则;把这个法则反过来,得到sb+ac+ad =a(b+c+d),这是运用提取公因式法把多项式因式分解.又如(a±b)2=a2±2ab+b2、(a+b)(a﹣b)=a2﹣b2是多项式的乘法公式;把这些公式反过来,得到a2±2ab+b2=(a±b)2、a2﹣b2=(a+b)(a﹣b),这是运用公式法把多项式因式分解.把多项式乘多项式法则(a+b)(c+d)=ac+ad+bc+bd反过来,将得到什么呢?事实上,ac+ad+bc+bd=a(c+d)+b(c+d)=(a+b)(c+d),这样多项式ac+ad+bc+bd 就分解为两个因式(a+b)与(c+d)的乘积.类似地,ac+bc+3a+3b=c(a+b)+3(a+b)=(a+b)(c+3).问题一:因式分解:(1)a2﹣ab+ac﹣bc;(2)9a2﹣6a+2b﹣b2.问题二:探究对x、y定义一种新运算F,规定:F(x,y)=(mx+ny)(3x﹣y)(其中m,n均为非零常数).当x2≠y2时,F(x,y)=F(y,x)对任意有理数x、y都成立,试探究m,n 的数量关系.27.(2020春•赣榆区期中)对于一个平面图形,通过两种不同的方法计算它的面积,可以得到一个数学等式,例如:图1可以得到(a+b)2=a2+2ab+b2,请解答下列问题:(1)写出图2所表示的数学等式:=;(2)已知上述等式中的三个字母a,b,c可取任意实数,若a=7k﹣5,b=﹣4k+2,c =﹣3k+4,且a2+b2+c2=37,请利用(1)所得的结论求ab+bc+ac的值;(3)小明同学用图3中2张边长为a的正方形,3张边长为b的正方形和m张邻边长分别为a、b的长方形纸片拼出一个长方形,通过拼图求出m的值.(求出1个即可)28.(2020春•玄武区期中)把几个图形拼成一个新的图形,再通过两种不同的方式计算同一个图形的面积,可以得到一个等式,也可以求出一些不规则图形的面积.例如,由图1,可得等式:(a+2b)(a+b)=a2+3ab+2b2.(1)由图2,可得等式;(2)利用(1)所得等式,解决问题:已知a+b+c=11,ab+bc+ac=38,求a2+b2+c2的值.(3)如图3,将两个边长为a、b的正方形拼在一起,B,C,G三点在同一直线上,连接BD和BF,若这两个正方形的边长a、b如图标注,且满足a+b=10,ab=20.请求出阴影部分的面积.(4)图4中给出了边长分别为a、b的小正方形纸片和两边长分别为a、b的长方形纸片,现有足量的这三种纸片.①请在下面的方框中用所给的纸片拼出一个面积为2a2+5ab+2b2的长方形,并仿照图1、图2画出拼法并标注a、b.②研究①拼图发现,可以分解因式2a2+5ab+2b2=.29.(2019秋•海门市期末)我们知道,任意一个正整数n都可以进行这样的分解:n=p×q (p,q是正整数,且p≤q),在n的所有这种分解中,如果p,q两因数之差的绝对值最小,我们就称p×q是n的完美分解.并规定:F(n)= .例如18可以分解成1×18,2×9或3×6,因为18﹣1>9﹣2>6﹣3,所以3×6是18的完美分解,所以F(18)=36=12.(1)F(13)=,F(24)=;(2)如果一个两位正整数t,其个位数字是a,十位数字为b﹣1,交换其个位上的数与十位上的数得到的新数减去原来的两位正整数所得的差为36,那么我们称这个数为“和谐数”,求所有“和谐数”;(3)在(2)所得“和谐数”中,求F(t)的最大值.30.(2019秋•柘城县期末)下面是某同学对多项式(x2﹣4x+2)(x2﹣4x+6)+4进行因式分解的过程.解:设x2﹣4x=y,原式=(y+2)(y+6)+4(第一步)=y2+8y+16(第二步)=(y+4)2(第三步)=(x2﹣4x+4)2(第四步)(1)该同学第二步到第三步运用了因式分解的.A.提取公因式B.平方差公式C.两数和的完全平方公式D.两数差的完全平方公式(2)该同学因式分解的结果是否彻底?.(填“彻底”或“不彻底”)若不彻底,请直接写出因式分解的最后结果.(3)请你模仿以上方法尝试对多项式(x2﹣2x)(x2﹣2x+2)+1进行因式分解.2021年江苏中考数学冲刺专题训练——专题2整式、因式分解参考答案与试题解析一.选择题(共2小题)1.【解答】解:设AB=x,AD=y,∵正方形ABEF和ADGH的面积之和为17cm2∴x2+y2=17,∵矩形ABCD的周长是10cm∴2(x+y)=10,∵(x+y)2=x2+2xy+y2,∴25=17+2xy,∴xy=4,∴矩形ABCD的面积为:xy=4cm2,故选:B.2.【解答】解:∵a﹣2b+c=0,a+2b+c<0,∴a+c=2b,b= + 2,∴a+2b+c=(a+c)+2b=4b<0,∴b<0,∴b2﹣ac=( + 2)2− = 2+2 + 24−ac= 2−2 + 24=( − 2)2≥0,即b<0,b2﹣ac≥0,故选:D.二.填空题(共8小题)3.【解答】①(a+2b)2=a2+4ab+4b2,要用A型卡片1张,B型卡片4张,C型卡片4张,所以可拼成边长为a+2b的正方形.②(2a+3b)2=4a2+12ab+9b2,要用A型卡片4张,B型卡片12张,C型卡片9张,因为B型卡片只有11张,C型卡片只有7张,所以不能拼成边长为2a+3b的正方形.③(2a+4b)(2a+b)=4a2+2ab+8ab+4b2=4a2+10ab+4b2,可得A型卡片4张,B型卡片10张,C型卡片4张,所以可拼成长、宽分别为2a+4b、2a+b的长方形.④所有卡片面积和为4a2+11ab+7b2=(4a+7b)(a+b).所以所有卡片可拼长长为(4a+7b),宽为(a+b)的长方形.故答案为:①③④.4.【解答】解:4块A的面积为:4×m×m=4m2;4块B的面积为:4×m×n=4mn;2块C的面积为2×n×n=2n2;那么这三种类型的砖的总面积应该是:4m2+4mn+2n2=4m2+4mn+n2+n2=(2m+n)2+n2,因此,多出了一块C型地砖,去掉一块C型地砖,这两个数的平方为(2m+n)2.这样的地砖拼法可以得到一个关于m,n的恒等式为:4m2+4mn+n2=(2m+n)2故答案为:4m2+4mn+n2=(2m+n)2.5.【解答】解:设AB=CD=x,AD=BC=y,则S1=6(AB﹣6)+(CD﹣5)(BC﹣6)=6(x﹣6)+(x﹣5)(y﹣6),S2=6(BC﹣6)+(BC﹣5)(CD﹣6)=6(y﹣6)+(y﹣5)(x﹣6),∴S2﹣S1=6(y﹣6)+(y﹣5)(x﹣6)﹣6(x﹣6)﹣(x﹣5)(y﹣6)=6y﹣36+xy﹣6y﹣5x+30﹣6x+36﹣xy+6x+5y﹣30=5y﹣5x=5(y﹣x),∵AD﹣AB=3,∴y﹣x=3,∴原式=5×3=15,故答案为:15.6.【解答】解:原式=2(m2﹣2mn+n2)=2(m﹣n)2,故答案为:2(m﹣n)27.【解答】解:原式=(x+3)(x﹣3),故答案为:(x+3)(x﹣3).8.【解答】解:∵m2=n+2,n2=m+2(m≠n),∴m2﹣n2=n﹣m,∵m≠n,∴m+n=﹣1,∴原式=m(n+2)﹣2mn+n(m+2)=mn+2m﹣2mn+mn+2n=2(m+n)=﹣2.故答案为﹣2.9.【解答】解:∵a=12018+2017,b=12018+2018,c=12018+2019,∴a﹣b=﹣1,a﹣c=﹣2,b﹣c=﹣1,∴a2+b2+c2﹣ab﹣bc﹣ca=12×(2 2+2 2+2 2−2 −2 −2 )=12[( − )2+( − )2+( − )2]=12×[(−1)2+(−1)2+(−2)2]=12×(1+1+4)=12×6=3,故答案为:3.10.【解答】解:原式=4(x2﹣1)=4(x+1)(x﹣1),故答案为:4(x+1)(x﹣1)三.解答题(共20小题)11.【解答】解:(1)阴影部分的面积为两个正方形的面积差,即a2﹣b2;故答案为:a2﹣b2;(2)拼成的长方形的长为(a+b),宽为(a﹣b),所以面积为(a+b)(a﹣b);故答案为:(a+b)(a﹣b);(3)由(1)(2)可得,a2﹣b2=(a+b)(a﹣b);故答案为:a2﹣b2=(a+b)(a﹣b);(4)(Ⅰ)(a+b﹣2c)(a+b+2c)=[(a+b)﹣2c][(a+b)+2c]=(a+b)2﹣(2c)2=a2+2ab+b2﹣4c2;(Ⅱ)(2a+b﹣3c)(﹣2a+b+3c)=[b+(2a﹣3c)][b﹣(2a﹣3c)]=b2﹣(2a﹣3c)2=b2﹣4a2+12ac﹣9c2.12.【解答】解:(1)设(80﹣x)=a,(x﹣60)=b,则(80﹣x)(x﹣60)=ab=30,a+b=(80﹣x)+(x﹣60)=20,所以(80﹣x)2+(x﹣60)2=a2+b2=(a+b)2﹣2ab=400﹣60=340;故答案为:30,20,340;(2)设30﹣x=a,x﹣20=b,则ab=﹣10,a+b=10,∴(30﹣x)2+(x﹣20)2=a2+b2=(a+b)2﹣2ab=102﹣2×(﹣10)=120;(3)设2021﹣x=m,2020﹣x=n,则m2+n2=2019,m﹣n=1,∵(m﹣n)2=m2﹣2mn+n2,∴1=2019﹣2mn,∴mn=1009,即(2021﹣x)(x﹣2020)=﹣1009;(4)由题意得:DE=x﹣10,DG=x﹣25,则(x﹣10)(x﹣25)=400,设a=x﹣10,b=x﹣25,则a﹣b=15,ab=400,=(a+b)2=(a﹣b)2+4ab=152+4×400=1825.∴S阴13.【解答】解:原式=6a2+9ab﹣4ab﹣6b2−12(9a2+12ab+4b2)−32a2+2ab =6a2+9ab﹣4ab﹣6b2−92a2﹣6ab﹣2b2−32a2+2ab=ab﹣8b2,∵|a+12|+|b+1|=0,∴a+12=0,b+1=0,解得:a=−12,b=﹣1,当a=−12,b=﹣1时,原式=−12×(﹣1)﹣8×(﹣1)2=﹣712.14.【解答】解:(1)﹣22+(23)﹣1+(π﹣3)0=﹣4+32+1=−32;(2)a⋅a2⋅a3+(﹣2a3)2﹣a9÷(﹣a)3=a6+4a6﹣a9÷(﹣a3)=a6+4a6+a6=6a6;(3)(x+3)(x﹣3)﹣(x﹣2)2=x2﹣9﹣x2+4x﹣4=4x﹣13;(4)(m+2n﹣3)(m﹣2n+3)=[m+(2n﹣3)][m﹣(2n﹣3)]=m2﹣(2n﹣3)=m2﹣4n2+12n﹣9.15.【解答】解:(1)原式=3−3−4+2=3−3−4+3=﹣1;(2)原式=a2+2ab+b2﹣a2﹣2ab=b2.16.【解答】解:(1)(﹣1)2021+(﹣2)0+(12)﹣3=(﹣1)+1+8=8;(2)a•a3•a4﹣4a10÷a2+(﹣3a4)2=a8﹣4a8+9a8=6a8;(3)(x+5)(x﹣3)﹣x(x+2)=x2+2x﹣15﹣x2﹣2x=﹣15;(4)20212﹣2020×2022=20212﹣(2021﹣1)×(2021+1)=20212﹣20212+1=1.17.【解答】解:(1)原式=9a6÷a2=9a4;(2)原式=﹣8a3+a•9a2=﹣8a3+9a3=a3;(3)原式=﹣4+1+2=﹣1;(4)原式=258×(258×825)11×(﹣8)=258×111×(﹣8)=258×1×(﹣8)=﹣25.18.【解答】解:(1)原式=(﹣3y)3=﹣27y3;(2)原式=8a6+27a6=35a6;(3)原式=1﹣4+32×(﹣1)=1﹣4﹣32=﹣35;(4)原式=x2+xy﹣(4x2+12xy+9y2)=x2+xy﹣4x2﹣12xy﹣9y2=﹣3x2﹣11xy﹣9y2;(5)原式=9a2﹣4b2﹣4a2=5a2﹣4b2.19.【解答】解:(1)①因为53=125,所以(5,125)=3;因为(﹣2)5=﹣32,所以(﹣2,﹣32)=5;②由新定义的运算可得,x﹣4=116,因为(±2)﹣4=1(±2)4=116,所以x=±2,故答案为:①3,5;②±2;(2)因为(4,5)=a,(4,6)=b,(4,30)=c,所以4a=5,4b=6,4c=30,因为5×6=30,所以4a•4b=4c,所以a+b=c.20.【解答】解:(1)|−2|+( −3)0−(13)−2+(−1)2021=2+1﹣9+(﹣1)=﹣7;(2)(﹣2×1012)×(﹣2×102)3÷(0.5×103)3=(﹣2×1012)×(﹣23×106)÷(123×109)=27×109=128×109=1.28×1011;(3)(−12 2)×(23 2 −6 )=−13x3y3+3x2y3;(4)(a﹣2b+3c)×(a+2b﹣3c)=[a﹣(2b﹣3c)][a+(2b﹣3c)]=a2﹣(2b﹣3c)2=a2﹣4b2+12bc﹣9c2;(5)(﹣2m﹣3)2(3﹣2m)2=(2m+3)2•(3﹣2m)2=[(3+2m)(3﹣2m)]2=(9﹣4m2)2=81﹣72m2+16m4;(6)4×1.632+6.52×6.74+6.742=(2×1.63)2+2×3.26×6.74+6.742=3.262+2×3.26×6.74+6.742=(3.26+6.74)2=102=100.21.【解答】解:(1)2﹣1﹣(﹣0.5)0−4=12−1﹣2=−52;(2)(x﹣3)2+x(x﹣2)=x2﹣6x+9+x2﹣2x=2x2﹣8x+9.22.【解答】解:原式=12x﹣2x+23y2−32x+13y2=12x﹣2x+23y2−32x+13y2=﹣3x+y2,把x=﹣2,y=23代入得:原式=649.23.【解答】解:(1)利用正方形的面积公式可知:阴影部分的面积=a2﹣b2;故答案为:a2﹣b2;(2)由图可知矩形的宽是a﹣b,长是a+b,所以面积是(a+b)(a﹣b);故答案为:a﹣b,a+b,(a+b)(a﹣b);(3)(a+b)(a﹣b)=a2﹣b2(等式两边交换位置也可);故答案为:(a+b)(a﹣b)=a2﹣b2;(4)①解:原式=(10+0.3)×(10﹣0.3)=102﹣0.32=100﹣0.09=99.91;②解:原式=[2m+(n﹣p)]•[2m﹣(n﹣p)]=(2m)2﹣(n﹣p)2=4m2﹣n2+2np﹣p2.24.【解答】解:(1)25(a+b)2﹣9(a﹣b)2=(5a+5b)2﹣(3a﹣3b)2.=(5a+5b+3a﹣3b)[5a+5b﹣(3a﹣3b)]=(8a+2b)(2a+8b).=4(4a+b)(a+4b).(2)16ab2﹣6a3﹣4ab2=12ab2﹣6a3=6a(2b2﹣a2)=6a(2b+a)(2b﹣a).(3)原式=(x2﹣4x+4)2=[(x﹣2)2]2=(x﹣2)425.【解答】解:(1)原式=ax(x2﹣16)=ax(x+4)(x﹣4);(2)原式=(2x﹣3y﹣x)2=(x﹣3y)2;(3)原式=(m2+1+2m)(m2+1﹣2m)=(m+1)2(m﹣1)2.26.【解答】解:问题一、(1)a2﹣ab+ac﹣bc=a(a﹣b)+c(a﹣b)=(a﹣b)(a+c);(2)9a2﹣6a+2b﹣b2,=(3a+b)(3a﹣b)﹣2(3a﹣b)=(3a﹣b)(3a+b﹣2),问题二、∵F(x,y)=(mx+ny)(3x﹣y),F(y,x)=(my+nx)(3y﹣x),又∵F(x,y)=F(y,x),∴(mx+ny)(3x﹣y)=(my+nx)(3y﹣x),3mx2+(3n﹣m)xy﹣ny2=﹣nx2+(3n﹣m)xy+3my2,∵x2≠y2,∴3m=﹣n.27.【解答】解:(1)正方形的面积可表示为=(a+b+c)2;正方形的面积=各个矩形的面积之和=a2+b2+c2+2ab+2bc+2ac,∴(a+b+c)2=a2+b2+c2+2ab+2bc+2ac,故答案为(a+b+c)2;a2+b2+c2+2ab+2bc+2ac;(2)∵a=7k﹣5,b=﹣4k+2,c=﹣3k+4,a2+b2+c2=37,∴(7k﹣5﹣4k+2﹣3k+4)2=37+2(ab+bc+ac),∴ab+bc+ac=﹣18;(3)如图所示:2a2+7ab+3b2=(a+3b)(2a+b).∴m=7.28.【解答】解:(1)由题意得,(a+b+c)2=a2+b2+c2+2ab+2bc+2ac,故答案为,(a+b+c)2=a2+b2+c2+2ab+2bc+2ac;(2)∵a+b+c=11,ab+bc+ac=38,∴a2+b2+c2=(a+b+c)2﹣2(ab+ac+bc)=121﹣76=45;(3)∵a+b=10,ab=20,∴S=a2+b2−12(a+b)•b−12a2=12a2+12b2−12ab=12(a+b)2−32ab=12×102−32×20=阴影50﹣30=20;(4)①根据题意,作出图形如下:②由上面图形可知,2a2+5ab+2b2=(a+2b)(2a+b).故答案为(a+2b)(2a+b).29.【解答】解:(1)∵13=1×13,∴F(13)=113∵24=1×24=2×12=3×8=4×624﹣1>12﹣2>8﹣3>6﹣4∴F(24)=46=23故答案为:113;23.(2)原两位数可表示为10(b﹣1)+a,新两位数可表示为10a+b﹣1∴10a+b﹣1﹣10(b﹣1)﹣a=36∴10a+b﹣1﹣10b+10﹣a=36∴9a﹣9b=27∴a﹣b=3∴a=b+3(1<b<6且b为正整数)∴b=2,a=5;b=3,a=6,b=4,a=7,b=5,a=8b=6,a=9∴和谐数为15,26,37,48,59(3)∵F(15)=35,F(26)=213,F(37)=137,F(48)=68=34,F(59)=159.∵34>35>213>137>159,∴所有“和谐数”中,F(t)的最大值是34.30.【解答】解:(1)该同学第二步到第三步运用了因式分解的两数和的完全平方公式;故选:C;(2)该同学因式分解的结果不彻底,原式=(x2﹣4x+4)2=(x﹣2)4;故答案为:不彻底,(x﹣2)4;(3)(x2﹣2x)(x2﹣2x+2)+1=(x2﹣2x)2+2(x2﹣2x)+1=(x2﹣2x+1)2=(x﹣1)4.。