北师大版中学2019-2020学年八年级下学期英语期中考试试卷B卷
北师大版中学2019-2020学年八年级下学期英语期中考试试卷B卷一、从下面每小题的A,B,C三个选项中选出可以替换划线部分的最佳 (共8题;共16分)1. (2分)The girl is greatly interested in the song. The lyrics of it her thoughts and feelings.A . expressB . discussC . expectD . imagine2. (2分)Don't worry about me while you're away. I will ______ myself.A . take care ofB . take afterC . look forD . look forward to3. (2分)—Can you give me some on learning English?—Sure.You can learn it by reading English novels and watching English movies.A . suggestionsB . changesC . prizesD . dreams4. (2分)This hotel us a large house.A . provides, forB . offers, toC . provides, withD . offers, with5. (2分)-Why are you so tired these days?-Well, I have _________ homework to do.A . too muchB . too manyC . much tooD . many too6. (2分)—What does your favorite teacher look like?—She ____ tall and thin, and she __ long curly hair.A . is; isB . is; hasC . has; hasD . has; is7. (2分)—Could I a dictionary from you, David?—Sorry, I it to my cousin yesterday.A . lend, borrowedB . borrow, lendC . borrow, lentD . borrowed, lend8. (2分)Susan her bike and hurt her leg yesterday.A . took awayB . looked upC . fell offD . found out二、从下面每小题的A、B、C三个选项中选出最佳选项,使句子通顺、 (共7题;共14分)9. (2分)— Hello, my name is Johnson. I believe you have a room __________ for me.— Johnson? Oh, yes, Mr. Johnson. It's Room 1201, on the second floor.A . lookedB . waitedC . cleanedD . booked10. (2分)Hilary came back full of after her vacation, which seemed to be relaxing and refreshing.A . energyB . strengthD . experiences11. (2分)I love this song by Lady Gaga. Would you ________ the TV a bit, please? I can't hear it clearly.A . turn onB . turn offC . turn upD . turn down12. (2分)We were _____________ when we heard the _________ news yesterday.A . exciting; surpriseB . excited; surprisingC . exciting; surprisingD . exciting; surprised13. (2分)The shoes are 5,000 yuan and they are too _______.A . differentB . largeC . expensiveD . lovely14. (2分)— Why don't you ________ us to Huai'an?— That's a good idea.A . joinB . join inC . joiningD . joining in15. (2分)— I ______ do sports when I am free.— Well, I hope you can make a change(改变). Doing more exercise is good for you.A . alwaysB . usuallyC . often三、完形填空 (共1题;共10分)16. (10分)完形填空Li Dong is a farmer. He has a very big1On the farm, he grows oranges, grapes and bananas. Many people come to2his farm. He is a successful young man and becomes very famous.In 2003, he went back to his hometown3he finished middle school. “What work can I do?” he said to himself. Then he had an idea. “I'm interested_4farming. I can grow fruit!” He began to watch many5on TV about growing fruit. He also read a lot of books about it. Then he went to_6on Mr Wang's farm for two years. He learned a lot there.In 2005, he started his own fruit farm7 Li Dong's 8was small. But now, his farm is much9His fruits are very good. He sends them to many big10_food. He has a very happy family.(1)A . farmB . parkC . schoolD . shop(2)A . lookB . takeC . visitD . notice(3)A . sinceB . afterC . thoughD . so(4)A . inB . onC . atD . for(5)A . gamesB . concertsC . programmesD . plays(6)A . seeB . playC . eatD . work(7)A . At lastB . At that timeC . At this momentD . At once(8)A . bigB . biggerC . the biggestD . biggest(9)A . villagesB . schoolsC . citiesD . farms(10)A . healthyB . badC . terribleD . unhealthy四、阅读理解 (共5题;共36分)17. (6分)阅读理解King's College Summer School is anannual(每年的) training program for high school students at all levels who want to improvetheir English. Courses are given by the teachers of King's College and other colleges in New York. Trips to museums and culture centres are also organized.This year's summer school will be from July 25 to August 15. More informationis as follows:A . a newspaperB . a travel guideC . a textbookD . a telephone book(2)If you want to live with your relatives in New York, you will have to pay the school _______.A . $200B . $400C . $500D . $900(3)Which of the following statements is TRUE?A . The program will last two months.B . You can write to Thompson only in English.C . Chinese student can send applications only on July 10.D . You can get in touch with the school by e-mail or by telephone.18. (6分)阅读理解Black Spider(蜘蛛)was having trouble catching bugs(臭虫)in his web, while Grey Spider caught two bugs in his.“You are so lucky,” Black Spider said to Grey Spider. “You have two bugs while I have none. It's not fair(公平的).”“Everyone has lucky days and unlucky days. Let's eat the bugs together,” said Grey Spider.Black Spider decided to join Grey Spider for lunch.“You must do some special things to get lucky, is it magic?” Grey Spider whispered.“No, build your web!” said Black Spider. “Repair your web! Enlarge your web! Make your web wider!”“Is that all?”“Yes, build a new web!” said Grey Spider.After lunch, Black Spider went back and made a new web. He built his web wider. Once he was done he slept all through the night because he was very tired.In the morning, Black Spider was excited to see four bugs in his web. He told Grey Spider about it. Grey Spider smiled at Black Spider. “By enlarging your web, you have enlarged your possibility to catch all these bugs,” Grey Spider said. “There is chance all around us. Luck is everywhere. You need to work to make it so more good luc k comes your way.”(1)After the Black Spider built his web wider, he slept all night because_______ .A . he could do nothing but waitB . the bugs only came out at nightC . he could use the web next morningD . he got really tired building the web(2)Which of the following is close to the underlined(划线)sentence?A . Every coin has two sides.B . Every dog has its day.C . Everything has its cause.D . Every road leads to Rome.(3)What is the main idea of this passage?A . Always get a plan when you are in trouble.B . To show people how a spider catches bugs.C . Luck comes to those who work for it.D . Life is not always fair, so we need to find a way out.19. (8分)阅读理解Christina is an American girl. She is a good student. Every morning she gets up at 6:00. She has her breakfast at home. The she wears her uniform and goes to school. She studies hard every day. She eats in the dining room when she is in school. After school, she does her homework first, then she cleans the room and helps her mother with the dinner. Before she goes to bed, she usually reads some books. Then at 10:00 p. m. she goes to bed. On weekends, she plays sports, sees friends, joins the Chinese club. She wants to learn to speak Chinese. She thinks she is happy every day. What do you think?(1)What's the meaning(意思) of the word "has"?A . makesB . buysC . eatsD . sells(2)When she is in school, she eats .A . in the hallwaysB . in the dining roomC . in hotelD . in the classroom(3)Does she wear her uniform in school?A . Yes, she does.B . No, she doesn't.C . I don't know.D . OK!(4)On weekends, she .A . plays the violin, makes friends, does sportB . reads some books, sees friends, join the clubC . join the Chinese club, cleans the room, dancesD . does sports, sees friends, learns Chinese20. (10分) Mr. Brown was going away for a week. Before he left, he said to his son, "if anyone asks for me, you can tell him that your father has been out for doing something, and will be back in a week, then be sure to ask him to sit down for a cup of tea.""OK, Dad," said his son. But he was afraid his son couldn't remember this, he wrote these words down on a piece of paper and gave it to him. His son put it into his small pocket, took it out and looked at it every now and then.Four days passed, but no one came to see his father. The boy thought that there was no man to come and that the piece of paper was of no more use for him, so he burnt it that evening.The next afternoon, someone knocked at the door. The boy opened it. A man was standing at the door and said, "Where is your father?" The boy put his hand into his pocket at once and looked for the piece of paper. He could not find it. He suddenly remembered he had burnt it, so he shouted, "No more."The man was very surprised. He asked, "No more? I met your father last week. When did it happen?" "Burnt yesterday evening."(1)Mr. Brown told his son that _____.A . he would be away from home for four daysB . he would be back in seven daysC . he would be back in a monthD . he liked a cup of tea(2)Mr. Brown wrote the words down on ________.A . the wallB . the doorC . a piece of paperD . his son's pocket(3)A man came to visit the boy’s father on ________.A . the second dayB . the third dayC . the fourth dayD . the fifth day(4)The man was very surprised because _________.A . he thought the child's father was deadB . the child didn't ask him to sit downC . the child gave him a cup of teaD . he couldn't find that piece of paper(5)What was burnt? ___________.A . The piece of paper.B . Mr. Smith.C . The visitor.D . The boy.21. (6分)(1) If you want to find a job as a waiter, you can to apply for it.A . go to 6756 Main St. SouthgateB . go to 224 West Rose Ave. RichmondC . fax resume to 555-0001D . email resume: lewisnclark@(2)If you do office work at Francisco's Shoe Shop, you should .A . be trainedB . have experienceC . speak EnglishD . know Spanish(3)If you work as a guide, you can get an hour.A . $ 8B . $ 10C . $ 12D . $ 13五、语法填空 (共1题;共5分)22. (5分)阅读下面一段文章,然后用恰当的词填空Welcome to England! The weather of England is very changeable. It can be rainy, sunny, windy, warm, foggy or cold at any time of year. If it's raining when you get up in the morning, it can be hot and dry by the afternoon. The west of England is wetter than the east, and the north is cooler than the south. Just be ready for any kind of weather.In England, shops are usually open from 9:00 am to 5:30 pm. On Sundays, some shops are open from 10:00 am to 4:00 pm. But a lot of shops are closed. Banks, museums of other places are open from 10:00 am to 5:00 pm. You can go to the parks at anytime.All the cities have buses, trains and taxis. People wait in line for buses and they are unhappy if you push in at the front. Don't forget this---traffic goes on the left. Be careful!Notice to the Tourists★Just be ready for any kind of ________, it's changeable.★Shops are usually open from ________ to 5:30 pm. On Sundays most of them are closed.★At any tim e you can go to the ________.★Please wait in line for buses, or others will be ________.★Make sure to drive on the ________, or it will be very dangerous.六、书面表达 (共1题;共5分)23. (5分)中澳友好协会准备就“A Gift from the Heart”为题举办征文比赛,要求参赛者分享在一些特别的日子(生日、节日……)用心准备的礼物。
北京师范大学附属实验中学2024-2025学年八年级上学期期中数学试题[含答案]
北师大实验中学2024—2025学年度第一学期初二年级数学期中考试试卷试卷说明:1.本试卷考试时间为100分钟,总分数为110分.2.本试卷共8页,四道大题,28道小题.3.请将答案都写在答题纸上.4.一律不得使用涂改液及涂改带,本试卷主观试题铅笔答题无效.5.注意保持卷面整洁,书写工整.A 卷一、选择题(本大题共8道小题,每小题2分,共16分)1.下列四届奥运会会徽中,是轴对称图形的是()A .B .C .D .2.下列计算,错误的是( )A .()3328a a =B .358a a a ×=C .624a a a ¸=D .()236a a -=-3.如图,ABC CDA △△≌,50BCA Ð=°,90B Ð=°,则CAD Ð的度数等于( )A .40°B .45°C .50°D .60°4.若分式21x x -+的值为0,则x 的值为A .﹣1B .0C .2D .﹣1或25.等腰三角形的一个角为50°,则顶角的度数为( )A .65°或50°B .80°C .50°D .50°或80°6.下列因式分解正确的是( )A .()ab ac a a b c ++=+B .()()22331a a a a --=+-C .()2222a ab b a b ++=+D .()()4221644a a a -=+-7.下列说法中正确的是( )A .如果两个三角形全等,则它们一定关于某直线成轴对称.B .到线段两个端点距离相等的点在这条线段的垂直平分线上.C .等腰三角形任意角的平分线与该角所对边的高线、中线互相重合.D .到角两边距离相等的点在这个角的平分线上.8.如图是22´的正方形网格,格线的交点称为格点,以格点为顶点的三角形称为格点三角形,图中的ABC V 为格点三角形,则正方形网格中与ABC V 成轴对称的格点三角形的个数是( )A .6个B .5个C .4个D .3个二、填空题(本大题共8道小题,每小题2分,共16分)9.若分式12x -有意义,则x 的取值范围是 .10.计算234x x -×= .11.如图,BE 、CD 交于点O ,且BE CD =,请添加一个条件,使得ABE ACD V V ≌,则可以添加的条件是: .12.如图,一个直角三角板的一条直角边经过AOB Ð的顶点O ,一把直尺经过三角板的直角顶点E 并且与这条直角边垂直,直尺与AOB Ð的两边分别交于C 、D ,当CE DE =时,AOE Ð与AOB Ð的数量关系为: .13.关于x 的多项式()()13x x n +-展开合并后一次项系数为1-,则n 的值为 .14.如图,射线OG 为AOB Ð的平分线,点P 为射线OG 上一点,PM OA ^于点M ,PN OB ^于点N ,且3PN =,点C 为OA 上一点,9OCP S =△,则OC = .15.如图,线段BD 为ABC V 的中线,且BD BC ^,4BC =,若45A C Ð+Ð=°,则BD = .16.如图,在等边ABC V 中,点P 、Q 在边BC 上,并且满足BP CQ =,连接AP 、AQ ,点N 为AC 上一动点,连接PN 、QN .(1)当PN NQ +最短时,测量CN = cm ;(精确到0.1cm )(2)若4AB =,则在点P 从B 运动到C 的过程中,PN QN +最短时,CN = .三、解答题(本大题共10道小题,其中第17至21题每题8分,第22至23题每题6分,第24题5分,第25题4分,第26题7分,共68分)17.计算:(1)()()421x x x --+(2)()2322682a bc a b a b -¸18.计算:(1)22246ab c a c b c-׸(2)22331a a a a a a a -+æö××ç÷-+èø19.把下列各式分解因式:(1)221218xy xy x-+(2)()222a b a --20.如图,射线OM 平分BOA Ð.(1)按要求尺规作图:作线段AB 的垂直平分线交射线OM 于点C ,连接CB 、CA .(保留作图痕迹)(2)请把以下解题过程补充完整:求证:180OBC OAC Ð+Ð=°.证明:在OA 上截取OD OB =,连接CD .OM Q 平分BOAÐBOM AOM\Ð=Ð在OBC △与ODC V 中:_______OB OD BOM AOM=ìïÐ=Ðíïî①OBC ODC \≌△△(②)CD CB \=,OBC ODCÐ=ÐQ 点C 在线段AB 的垂直平分线上CB CA \=(③)CD CA\=CDA CAD \Ð=Ð(④)Q 点D 在射线OA 上180ODC CDA \Ð+Ð=°180OBC OAC \Ð+Ð=°21.如图,在平面直角坐标系xOy 中,()2,1A --,()1,2B -,连接AB .(1)画线段11A B ,使得线段11A B 与线段AB 关于y 轴对称,并写出11A B 的坐标:1A _______,1B _______;(2)如果点C 在y 轴上,且ABC V 是等腰三角形,试着写出一个满足条件的点C 的坐标:_______.这样符合条件的点C 共有_______个.22.化简求值:当2610x x --=时,求()()()23233x x x --+-的值.23.如图,等腰ABC V 中,AB AC =,AD BC ^于D ,过点D 分别作DE AB ^交AB 于点E ,DF AC ^交AC 于点F .求证:BE CF =.24.如图1,小长方形的长和宽分别为a 和b ,将四块这样的长方形按如图2所示位置摆放.(1)图2中的四边形EFGH 为正方形,其边长为_______.(2)能用图2中的图形面积关系来验证的等式是:_______=_______.(3)若3x y -=,4xy =,求x y +的值.25.已知:如图,36MON Ð=°,射线OM 、ON 上分别有点A 和点B ,点P 在线段OB 上,连接PA ,()0144OAB a a Ð=°<<°.若线段PA 将AOB V 分割为两个等腰三角形,则称线段PA 为AOB V 的“a 角等分线”.(1)如图1,当90a =°时,画出AOB V 的“90角等分线”此时OAP Ð=_______°.(2)当90a ¹°时,若存在线段PA 为AOB V 的“a 角等分线”,则a =_______°.26.如图1所示,在ABC V 中,AB AC =,2BAC a Ð=()4590a °<<°,D 为线段BC 上一点,E 为CD 中点,连接AE .作EAM a Ð=,得到射线AM ,过点E 作EF AE ^交射线AM 于点F .(1)依题意补全图形;(2)求证:B AFE Ð=Ð;(3)如图2,当60a =°时,连接BF 、DF ,求证:FBD V 为等边三角形.B 卷四、填空题(本大题共两道小题,其中27题4分,28题6分,共10分)27.如图,点B 在线段AC 上,点E 在线段BD 上,ABD DBC Ð=Ð,AB DB =,EB CB =,M ,N 分别是线段AE 、CD 的中点.以下结论正确的是: .①AE CD =;②AE CD ^;③AE 平分DAC Ð;④BM BN ^且BM BN=28.在平面直角坐标系xOy 中,已知点(),R a b .对于点P 给出如下定义:先将点P 向右()0a ³或向左()0a <平移a 个单位长度,再关于直线y b =对称,得到点P ¢,则称点P'为点P 的“R 关联点”(1)如图1,点P 坐标为()3,1①当点R 坐标为()1,2-时,则点P 的“R 关联点”P ¢的坐标为:_______;②若点()4,3Q -为点P 的“R 关联点”,则R 的坐标为_______;(2)如图2,点A (−2,0)、C (0,1),点B 与点A 关于y 轴对称.点R 在ABC V 边上,点P 坐标为()5,0①画出点P 所有的“R 关联点”;②这些关联点组成的图形形状是:_______.(3)如图3,点(),E n n -、(),F n n --、(),G n n -、(),H n n ,0n >,点R 在正方形EFGH 边上,点()6,4M 、()7,5N ,若线段MN 上存在点()3,0P n 的“R 关联点”,直接写出n 的取值范围.1.A【分析】本题考查了轴对称图形的概念,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.根据如果一个图形沿一条直线折叠,直线两旁的部分能够互相重合,这个图形叫做轴对称图形,这条直线叫做对称轴进行分析即可.【详解】解:B ,C ,D 选项中的图形都不能找到一条直线,使图形沿一条直线折叠,直线两旁的部分能够互相重合,所以不是轴对称图形;A 选项中的图形能找到一条直线,使图形沿一条直线折叠,直线两旁的部分能够互相重合,所以是轴对称图形;故选:A .2.D【分析】本题考查同底数幂的乘除法、幂的乘方与积的乘方,熟练掌握运算法则是解题的关键.根据同底数幂的乘除法法则、幂的乘方与积的乘方法则进行计算即可.【详解】解:A 、()3328a a =,故该项正确,不符合题意;B 、358a a a ×=,故该项正确,不符合题意;C 、624a a a ¸=,故该项正确,不符合题意;D 、()236a a -=,故该项不正确,符合题意;故选:D .3.C【分析】本题考查了全等三角形的性质,由三角形全等可知ACB CAD Ð=Ð,进而即可得出答案.【详解】解:Q ABC CDA △△≌,ACB CAD Ð=Ð\,Q 50BCA Ð=°,50CAD \Ð=°,故选:C .4.C【分析】根据分式值为零的条件可得x ﹣2=0,再解方程即可.【详解】解:由题意得:x ﹣2=0,且x +1≠0,解得:x =2,故选C .5.D【分析】分50°角是等腰三角形的顶角和底角两种情况计算,熟练掌握等边对等角,三角形内角和定理是解题的关键.【详解】当50°角是等腰三角形的顶角时,顶角的度数是50°;当50°角是等腰三角形的底角时,顶角的度数是180505080°-°-°=°;故选D.6.C【分析】本题考查因式分解,熟记乘法公式,掌握提公因式法和公式法分解因式的步骤和要求是解答的关键.利用提公因式法或公式法对每个选项中的式子进行因式分解,进而可作出判断.【详解】解:A 、()1ab ac a a b c ++=++,原计算错误,不符合题意;B 、()()22331a a a a --=-+,原计算错误,不符合题意;C 、()2222a ab b a b ++=+,原计算正确,符合题意;D 、()()()()()42221644422a a a a a a -=+-=++-,原计算错误,不符合题意;故选:C .7.B【分析】本题考查了全等三角形的性质,等腰三角形的性质,线段垂直平分线的判定及角平分线的判定,熟练掌握全等三角形的性质,等腰三角形的性质,线段垂直平分线的判定及角平分线的判定依次进行判断即可.【详解】解:如果两个三角形全等,则它们不一定关于某直线成轴对称,故A 选项不符合题意;到线段两个端点距离相等的点在这条线段的垂直平分线上,故B 选项符合题意;等腰三角形顶角的平分线,底边上的中线和底边上的高相互重合,故C 选项不符合题意;在角的内部到角两边距离相等的点在这个角的平分线上,故D 选项不符合题意,故选:B .8.B【分析】本题考查了利用轴对称变换作图,熟练掌握网格结构并准确找出对应点的位置是解题的关键,根据网格结构分别确定出不同的对称轴,然后作出轴对称三角形即可得解.【详解】解:如图所示,BCD △,EBC V ,MHN V ,BAO V 与ABC V 成轴对称∴共5个.故选:B .9.2x ¹【分析】本题主要考查了分式有意义的条件,根据分式有意义的条件是分母不为0进行求解即可.【详解】解:∵分式12x -有意义,∴20x -¹,∴2x ¹,故答案为:2x ¹.10.312x -【分析】此题考查的是单项式乘单项式,解决此题的关键是掌握单项式乘单项式的运算法则.直接根据单项式乘单项式的运算法则计算即可.【详解】解:原式312x =-.故答案为:312x -.11.B C Ð=Ð(答案不唯一)【分析】本题主要考查了全等三角形的判定,关键是掌握判定两个三角形全等的一般方法.添加条件:B C Ð=Ð,再由已知条件BE CD =和公共角A Ð可利用AAS 定理证明ABE ACD V V ≌.【详解】解:添加条件:B C Ð=Ð,在ABE V 和ACD V 中,A ABC BE CD Ð=ÐìïÐ=Ðíï=î,\()AAS ABE ACD V V ≌,故答案为:B C Ð=Ð(答案不唯一).12.12AOE AOB Ð=Ð【分析】本题考查了全等三角形的性质与判定,解决本题的关键是熟练掌握全等三角形的性质与判定.根据SAS 可以证明OEC OED V V ≌,从而得结论.【详解】解:由题意得OE CD ^,90OEC OED \Ð=Ð=°,在OEC △和OED V 中,CE DE OEC OED OE OE =ìïÐ=Ðíï=î,(SAS)OEC OED \V V ≌,AOE BOE \Ð=Ð,12AOE AOB \Ð=Ð,故答案为:12AOE AOB Ð=Ð.13.4【分析】本题考查了多项式乘以多项式的法则的应用,关键是理解展开合并后一次项系数为1-.根据多项式乘以多项式法则展开后,根据x 项的系数等于1-可得出n 的值.【详解】解:()()()22133333x x n x nx x n x n x n+-=-+-=+--Q 一次项系数为1-,31n \-=-4n \=,故答案为:4.14.6【分析】本题主要考查了角平分线的性质定理,熟练掌握角平分线上的点到角两边的距离相等是解题的关键.首先根据角平分线的性质定理得到3PM PN ==,然后利用9OCP S =△代数求解即可.【详解】解:∵射线OG 为AOB Ð的平分线,PM OA ^,PN OB ^,且3PN =,∴3PM PN ==;∵9OCP S =△,∴192OC MP ×=,即1392OC ´=,∴6OC =.故答案为:6.15.2【分析】本题考查了全等三角形的判定和性质、等腰三角形的判定.解题的关键是作辅助线,构造全等三角形.延长BD 至点E ,使得DE BD =,连接CE ,证明ADB CDE △△≌,可得ECD A Ð=Ð,再证得45BCE Ð=°,最后根据等腰三角形判定求解可.【详解】解:如图,延长BD 至点E ,使得DE BD =,连接CE ,在ADB V 和CDE V 中,AD CD ADB CDE BD DE =ìïÐ=Ðíï=î,()SAS ADB CDE \V V ≌,ECD A \Ð=Ð,45A BCD Ð+Ð=°Q ,45ECD BCD \Ð+Ð=°,45BCE \Ð=°,BD BC ^Q ,45BCE BEC \Ð=Ð=°,4BE BC \==,122BD BE \==,故答案为:216. 0.5 1【分析】本题考查了等边三角形的性质和判定,三角形的外角,两点之间线段最短问题.(1)作点Q 关于直线AC 的对称点Q ¢,连接PQ ¢,交AC 于点N , 根据“两点之间线段最短”可知,此时PN NQ +最短,测量出CN 即可;(2)连接AQ CQ ¢¢,,根据题意证明()SAS ABP ACQ V V ≌,结合点Q 关于直线AC 的对称点Q ¢,证明()SSS AQC AQ C ¢V V ≌,因此AP AQ AQ BAP CAQ CAQ ¢¢==Ð=Ð=Ð,,进而证明APQ ¢△是等边三角形,根据“两点之间线段最短”可知,要使PN QN +最短,则P 、N 、Q ¢三点共线,此时PN NQ PQ ¢+=,又因为AP PQ ¢=,即AP 最小,过点A 作^AP BC 于点P ,此时AP 最小,由QN Q N ¢=,APQ ¢△是等边三角形,得AN PQ ¢^,再结合30NPC Ð=°,4AB =,即可求出答案.【详解】解:(1)作点Q 关于直线AC 的对称点Q ¢,连接PQ ¢,交AC 于点N ,此时PN NQ +最短,则测量0.5cm CN =;(2)连接AQ CQ ¢¢,,在等边ABC V 中,60AB AC B ACB =Ð=Ð=°,,BP CQ =Q ,()SAS ABP ACQ \V V ≌,Q 点Q 关于直线AC 的对称点Q ¢,AQ AQ CQ CQ ¢¢\==,,AC AC =Q ,()SSS AQC AQ C \¢V V ≌,AP AQ AQ BAP CAQ CAQ ¢¢\==Ð=Ð=Ð,,60BAC Ð=°Q ,60PAQ ¢\Ð=°,APQ ¢\V 是等边三角形,AP PQ ¢\=,PN QN PN NQ PQ ¢¢+=+³Q ,\要使PN QN +最短,则P 、N 、Q ¢三点共线,此时PN NQ PQ ¢+=,AP PQ ¢=Q ,即AP 最小,过点A 作^AP BC 于点P ,此时AP 最小,Q ABC V 为等边三角形,BP CP \=,Q BP CQ =,\此时P 、Q 重合,QN Q N ¢=Q ,APQ ¢△是等边三角形,AN PQ ¢\^,90906030NPC ACB \Ð=°-Ð=°-°=°,Q 4AB =,11222CP BC AB \===,112CN CP \==,\PN QN +最短时,1=CN ,故答案为:1.17.(1)2491x x --(2)34c ab-【分析】此题主要考查了整式的混合运算,正确掌握相关运算法则是解题关键.(1)直接利用单项式乘多项式法则进行化简,再去括号,最后合并进而得出答案;(2)直接利用多项式除以单项式法则计算得出答案.【详解】(1)解:原式2481x x x =---,2491x x =--;(2)解:原式34c ab=-18.(1)23-(2)3a -【分析】本题考查了分式的乘法运算和分式的除法运算,熟记分式的运算法则是解题的关键.(1)根据分式的乘除法则,先将除法转化为乘法,再约分化简即可;(2)先将分子分母因式分解,再约分化简即可.【详解】(1)解:22246ab c a c b c-׸22246ab c c c b a-××=23=-;(2)22331a a a a a a a -+æö××ç÷-+èø()()223131a a a aa a a -+=××-+3a =-.19.(1)()223x y -(2)()()3a b a b --【分析】此题考查了因式分解的方法,解题的关键是熟练掌握因式分解的方法:提公因式法,平方差公式法,完全平方公式法,十字相乘法等.(1)先提公因式,然后利用完全平方公式因式分解即可.(2)利用平方差公式因式分解即可.【详解】(1)221218xy xy x-+()2269x y y =-+()223x y =-;(2)()222a b a --()()22a b a a b a =-+--()()3a b a b =--.20.(1)见解析(2)OC OC =;SAS ;线段垂直平分线的性质;等边对等角【分析】本题考查尺规作图,全等三角形的判定与性质,线段垂直平分线的性质,等腰三角形的判定,熟练的作图是解本题的关键.(1)按题意作出图形即可;(2)根据全等三角形的判定与性质、线段垂直平分线的性质及等腰三角形的判定,逐步填写推理过程与推理依据即可.【详解】(1)解:如图;.(2)证明:在OA 上截取OD OB =,连接CD .OM Q 平分BOAÐBOM AOM\Ð=Ð在OBC △与ODC V 中:OB OD BOM AOMOC OC =ìïÐ=Ðíï=î()SAS OBC ODC \V V ≌CD CB \=,OBC ODCÐ=ÐQ 点C 在线段AB 的垂直平分线上CB CA \=(线段垂直平分线的性质)CD CA\=CDA CAD \Ð=Ð(等边对等角)Q 点D 在射线OA 上180ODC CDA \Ð+Ð=°180OBC OAC \Ð+Ð=°故答案为:OC OC =;SAS ;线段垂直平分线的性质;等边对等角21.(1)图见解析,()12,1A -,()11,2B ;(2)()0,0,4.【分析】()1根据轴对称的性质画出图形并写出对称点的坐标即可;()2选取一点与线段AB 构成等腰三角形分三种情况:以点A 为等腰三角形的顶点AB 为腰;以点B 为等腰三角形的顶点AB 为腰;以AB 为等腰三角形的底边时,则等腰三角形的顶点在线段AB 的垂直平分线上.【详解】(1)解:如下图所示,分别作点A 、B 关于y 轴的对称点1A 、1B ,连接11A B ,线段11A B 与线段AB 关于y 轴对称;Q 已知点A 、B 的坐标分别是()2,1--、()1,2-,1A \的坐标是()2,1-,1B 的坐标是(1,2);(2)解:当以点A 为等腰三角形的顶点AB 为腰时,在y 轴上有2个点可以与线段AB 组成等腰三角形,如下图所示,当以点B 为等腰三角形的顶点AB 为腰时,在y 轴上有两个点使3C B AB =、4C B AB =,可以看出点A 、B 、3C 在同一条直线上,不能构成三角形,\在y 轴上有1个点可以与线段AB 组成等腰三角形,如下图所示,当以AB 为等腰三角形的底边时,则等腰三角形的顶点在线段AB 的垂直平分线上,如下图所示,可以发现这个点恰好是原点.综上所述,在y 轴上有4个点可以与线段AB 构成等腰三角形,其中一个满足条件的点是()0,0.【点睛】本题考查了轴对称变换和等腰三角形的性质.关于y 轴对称的两个点的纵坐标相等,横坐标互为相反数;有两条边相等的三角形是等腰三角形.22.23【分析】此题考查了整式乘法的混合运算,化简求值,熟练掌握运算法则是解决本题的关键.原式第一项利用完全平方公式展开,第二项利用平方差公式化简,去括号合并得到最简结果,将已知等式整体变形代入计算即可求值.【详解】解:∵2610x x --=∴261x x -=∴22122x x -=()()()23233x x x --+-()()223449x x x =-+--22312129x x x =-+-+221221x x =-+221=+23=.23.见解析【分析】此题考查了等腰三角形三线合一性质,等边对等角,全等三角形的性质和判定等知识,解题的关键是掌握以上知识点.首先由三线合一性质和等边对等角得到BD CD =,B C Ð=Ð,然后证明出()AAS BDE CDF ≌△△,.即可得到BE CF =.【详解】解:∵等腰ABC V 中,AB AC =,AD BC ^于D ,∴BD CD =,B CÐ=Ð∵DE AB ^,DE AB^∴90BED CFD Ð=Ð=°∴()AAS BDE CDF ≌△△∴BE CF =.24.(1)()a b -(2)()2a b -,()24a b ab+-(3)5x y +=±【分析】此题考查了列代数式,完全平方公式和几何图形的应用,利用完全平方公式的变形求值,解题的关键是掌握以上知识点.(1)由小长方形的长和宽分别为a 和b 求解即可;(2)分别用两种方法表示出正方形EFGH 的面积即可求解;(3)由(2)得()()224x y x y xy -=+-,然后整体代数求解即可.【详解】(1)解:∵小长方形的长和宽分别为a 和b ,∴图2中的四边形EFGH 为正方形,其边长为()a b -;(2)解:正方形EFGH 的面积为()22EF a b =-;正方形EFGH 的面积还可以表示为()24a b ab +-;∴()()224a b a b ab -=+-;(3)解:由(2)得,()()224x y x y xy-=+-∵3x y -=,4xy =,∴()22344x y =+-´∴()225x y +=∴5x y +=±.25.(1)画图见解析;36;(2)72或108【分析】本题考查了等腰三角形的性质与判定、三角形内角和定理及外角的性质,解决本题的关键是熟练掌握等腰三角形的性质与判定.(1)作出线段OB 的中点P ,连接AP ,线段PA 为AOB V 的“90角等分线”,再根据直角三角形性质及等腰三角形性质求解即可;(2)作出图形并分两种情况讨论:作72OAB Ð=°,OB 交ON 于点B ,在线段上作点P ,使得OP AP =;作108OAB Ð=°,OB 交ON 于点B ,在线段上作点P ,使得OP AP =,再求解即可.【详解】(1)解:如图,作出线段OB 的中点P ,连接AP ,线段PA 为AOB V 的“90角等分线”,Rt AOB Q △中,AP 是斜边上的中线,OP AP PB \==,\线段PA 将AOB V 分割为两个等腰三角形,\线段PA 为AOB V 的“90角等分线”,36OAP MON \Ð=Ð=°,故答案为:36;(2)解:如图,作72OAB Ð=°,OB 交ON 于点B ,在线段上作点P ,使得OP AP =,36MON Ð=°Q ,OP AP =,36OAP MON \Ð=Ð=°,72OAB Ð=°Q ,723636PAB \Ð=°-°=°,72APB MON OAP Ð=Ð+Ð=°Q ,18072ABP PAB APB Ð=°-Ð-Ð=°Q ,ABP APB \Ð=Ð,AP AB \=,\线段PA 将AOB V 分割为两个等腰三角形,72a =°;如图,作108OAB Ð=°,OB 交ON 于点B ,在线段上作点P ,使得OP AP =,36MON Ð=°Q ,OP AP =,36OAP MON \Ð=Ð=°,108OAB Ð=°Q ,1083672PAB \Ð=°-°=°,72APB MON OAP Ð=Ð+Ð=°Q ,PAB APB \Ð=Ð,AB PB \=,\线段PA 将AOB V 分割为两个等腰三角形,108a =°;故答案为:72或10826.(1)见详解(2)见详解(3)见详解【分析】本题考查了等边三角形的判定及性质,全等三角形的判定及性质,等腰三角形的判定及性质等;(1)按要求补全图形,即可求解;(2)由角的和差得90AFE EAF Ð=°-Ð,由等腰三角形的性质得()118022B a Ð=°-,即可求证;(3)延长AE 至H 使AE EH =,连接,DH FH ,证明()SAS AEC HED V V ≌得出AC DH =,CAE EHD Ð=Ð,进而证明DHF BAF Ð=Ð,证明()SAS ABF HDF V V ≌,推出FB FD =,AFB HFD Ð=Ð,即可得出60BFD AFH Ð=Ð=°,则FBD V 为等边三角形.【详解】(1)解:如图,(2)证明:Q EF AE ^,90AEF \Ð=°,90AFE EAF\Ð=°-Ð90a =°-,AB AC =Q ,2BAC a Ð=,()118022B a \Ð=°-90a =°-,\B AFE Ð=Ð;(3)证明:延长AE 至H 使AE EH =,连接,DH FH ,∵,,AE EH AEC HED DE EC=Ð=Ð=∴()SAS AEC HED V V ≌∴AC DH =,CAE EHDÐ=Ð又∵AB AC=∴AB DH=∵60a =°,则120BAC Ð=°,60FAE Ð=°∴60BAF EACÐ=°-Ð∵EF AH ^,AE EH=∴AF FH =,∴60DHF AHF EHD EAC BAC FAE EAC BAFÐ=Ð-Ð=°-Ð=Ð-Ð-Ð=Ð∴()SAS ABF HDF V V ≌∴FB FD =,AFB HFDÐ=Ð∴60BFD AFH Ð=Ð=°∴FBD V 为等边三角形.27.①②④【分析】本题主要考查全等三角形的性质与判定,三角形内角和定理等知识,熟练掌握全等三角形的判定方法是解题的关键.首先证明出()SAS ABE DBC V V ≌,得到AE CD =,即可判断①;延长AE 交CD 于点F ,得到EAB BDC Ð=Ð,然后结合三角形内角和 得到90ABD DFE ==°∠∠,即可判断②;根据题意无法证明AE 平分DAC Ð,即可判断③;证明出()ASA ABM DBN V V ≌,得到ABM DBN Ð=Ð,进而可判断④.【详解】解:在ABE V 和DBC △中,AB DB ABD DBC EB CB =ìïÐ=Ðíï=î,∴()SAS ABE DBC V V ≌,∴AE CD =,故①正确;如图所示,延长AE 交CD 于点F∵ABD DBC Ð=Ð,点B 在线段AC 上,∴90ABD DBC Ð=Ð=°∵ABE DBCV V ≌∴EAB BDCÐ=Ð∵AEB DEFÐ=Ð∴AE CD ^,故②正确;根据题意无法证明AE 平分DAC Ð,故③错误;∵ABE DBC V V ≌,M ,N 分别是线段AE 、CD 的中点∴BM BN=又∵MAB NDB Ð=Ð,AB BD=∴()ASA ABM DBN V V ≌∴ABM DBNÐ=Ð∴ABM DBM DBN DBMÐ+Ð=Ð+Ð∴90ABD MBN Ð=Ð=°∴BM BN ^,故④正确;综上所述,结论正确的是:①②④.故答案为:①②④.28.(1)①(2,3);②(1,1)-(2)①图见解析;②等腰三角形(3)522n ££或732n ££【分析】本题考查了坐标变换,解题关键是得到“R 关联点”变化规律.(1)根据“R 关联点”定义可得点P (,)x y 的“(),R a b 关联点”的坐标为(),2P x a b y ¢+-,据此计算即可;(2)①根据(),R a b 关联点的定义计算出当R 在三角形的顶点时,点P 的“R 关联点”坐标,即可画图;②由图可知关联点组成的图形形状是三角形.(3)分点R 在正方形的四条边上上时,坐标不同,根据()3,0P n 的“R 关联点”在线段MN 上方程和不等式求解即可.【详解】(1)解:设P 坐标为(,)x y ,设P ¢的坐标为(),P x y ¢¢¢,先将点P 向右()0a ³或向左()0a <平移a 个单位长度,得到点的坐标为(,)x a y +,再关于直线y b =对称,得到点P ¢,则2x x a y y b =+ì¢+=¢ïíïî,∴2x x a y b y =+ìí=-¢¢î即P ¢坐标为(),2x a b y +-①当点P 坐标为()3,1,点R 坐标为()1,2-时,则点P 的“R 关联点”P ¢的坐标为(31,221)-´-,即(2,3);②点()4,3Q -为点P ()3,1的“R 关联点”,∴43321a b =+ìí-=-î解得:11a b =ìí=-î,即R 的坐标为(1,1)-,(2)解:①如图②这些关联点组成的图形形状是等腰三角形.(3)∵点()6,4M 、()7,5N ,①当点R 在EH 上时,设点(,)R a n 其中n a n -££,则线段MN 上存在点()3,0P n 的“R 关联点”坐标为(3,2)n a n +,∴322n a n +-=,∴2a n=-又∵637n a n a n £+£ìí-££î即63(2)72n n n n n£+-£ìí-£-£î解得:522n ££,当点R 在EH 上时,522n ££, 线段MN 上存在点()3,0P n 的“R 关联点”②当点R 在FG 上时,设点(,)R a n -其中n a n -££,则线段MN 上存在点()3,0P n 的“R 关联点”坐标为(3,2)n a n +-,∵0n >,∴(3,2)n a n +-不可能在第一象限,故点R 在FG 上时,线段MN 上不存在点()3,0P n 的“R 关联点”;③当点R 在H G 上时,设点(,)R n b 其中n b n -££,则线段MN 上存在点()3,0P n 的“R 关联点”坐标为(4,2)n b ,∴422n b -=,∴21b n =-又∵647n n b n ££ìí-££î即64721n n n n££ìí-£-£î不等式组无解,故点R 在H G 上时,线段MN 上不存在点()3,0P n 的“R 关联点”;④当点R 在EF 上时,设点(,)R n b -其中n b n -££,则线段MN 上存在点()3,0P n 的“R 关联点”坐标为(2,2)n b ,∴222n b -=,∴1b n =-又∵627n n b n ££ìí-££î即6271n n n n££ìí-£-£î解得:732n ££,当点R 在EF 上时,732n ££, 线段MN 上存在点()3,0P n 的“R 关联点”综上所述:当522n ££或732n ££时,线段MN 上存在点()3,0P n 的“R 关联点”。
2019-2020学年浙江省嘉兴市北京师范大学南湖附属学校八年级第一学期期中英语试卷.(含解析)
2019-2020学年浙江省嘉兴市南湖区北师大南湖附校八年级第一学期期中考试英语试卷二、完形填空。
阅读下面短文,掌握其大意,然后在各题所给的四个选项中选出一个最佳答案。
Alex was a giraffe. He lived in a zoo with his mum, dad and other giraffe friends. As Alex grew, he___16__his neck was much shorter than the others’. He began to get__17__. But his mother told him that he was __18__. She said it did not matter how short or long his __19__ was.Alex tried not to __20__ his short neck. But as his friends grew taller and taller, his neck _21__ short. Sometimes the other giraffes__22___ him, but his parents told him not to worry. They said that he should be happy with _23__ the way he was. He tried, but he could not even play in some giraffe sports. He was just too _24___.One day, one of the zoo workers came and took Alex away. Alex was afraid. Would he have to leave the zoo just __25__ he didn’t have a long neck? The zoo worker calmed (使镇静) Alex down and gave him some food. He felt__26__. Then he led Alex into another area of the zoo. There was a small __27___ between the two areas. Alex was the only giraffe that could go through it.Soon Alex’s __28__ came to see him. “I told you that you were special.” his mother said. “The zoo has made a place just for __29__ because so many people want to see how special you are!”She was right. Tourists pointed to him and felt___30___. They looked happy to see something so special at the zoo.16 A.believed B.found C.hoped D.agreed17 A.careful B.great C.interested D.worried18 A.fat B.thin C.special mon19 A.leg B.neck C.foot D.hair20 A.go over B.find out C.think about D.look for21 A.stayed B.became C.turned D.felt22 A.looked after B.fell behind ughed at D.heard of23 A.herself B.himself C.themselves D.ourselves24 A.tall B.short C.fat D.thin25 A.after B.when C.because D.before26 A.better B.worse C.sadder D.angrier27 A.box B.hole C.window D.door28 A.grandparents B.parents C.teachers D.friends29 A.him B.you D.me30 A.excited B.angry C.sad D.heavy【答案】BDCBC ACBBC ADBBA【解答】16.考察动词。
2024年秋季高三北师大版(2019)开学摸底考试英语试卷 B卷(含解析)
2024年秋季高三北师大版(2019)开学摸底考试英语试卷 B卷考试时间:90分钟满分:120分第一部分阅读理解(共两节,满分50分)第一节(共15小题;每小题2.5分,满分37.5分)阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项。
AItaly ToursTake our well-designed Italy tour package to explore this charming land.4-6 DaysIf it is your first time to visit Italy, Rome, Florence and Venice are your best choices to learn about the essential history, culture and admire the masters’ artworks of this great country.7-9 DaysVenice in the north as a start, then to Florence, Pisa, Cinque Terre, lastly in Rome, this route covers popular cities, art, heritage as well as the beautiful Mediterranean coastline. For nature and sea lovers, Rome, Sorrento, Amalfi Coast and Capri Island could be nice destinations.10 Days or MoreThe typical 2-week Italy tour packages would cover top tourist cities and important landmarks. You could go through the country from North to South.Best Time to Visit: Spring from April to June; autumn from September to OctoberMajor Cities for International Flights: Rome (capital), Venice, Florence, NapoliVisa: Citizens from the USA, Canada, Australia, and citizens of EU and EEA countries do not need a visa and are allowed to stay up to 90 days. The Schengen visa can also be used for travelling to Italy.Money Tips: Euro is the official currency. Major credit cards are widely accepted, but cash is still necessary in some cases.1.Which places are recommended for those who have never visited Italy before?A. Rome, Florence and Venice.B. Capri Island, Venice and Pisa.C. Pisa, Florence and Cinque Terre.D. Rome, Sorrento and Amalfi Coast.2.Which tour package is designed for enjoying natural scenery?A.4 –6 Days.B.7 –9 Days.C.10 Days or More.D.2 Weeks.3.Which month may be the most suitable to visit Italy?A. March.B. May.C. August.D. November.BHoney is a simple pleasure. It’s easy to forget, while enjoying its luxurious sweetness on a slice of buttered toast, that it is the end-product of a complicated production line involving advanced biological machinery and thousands of skilled workers.Honey starts out as nectar (花蜜), a solution of various sugars that flowering plants produce to attract insects like butterflies and all kinds of bees. Most of these visitors drink it down on the spot as nutrition for themselves. A food-hunting worker bee, though, does things differently. The bee stores the nectar in its honey stomach rather than digesting it. The stomach can hold a lot of nectar, up to almost half the bee’s unloaded body mass, and filling it may require a thousand flower visits. The transformation of nectar into honey begins while the bee is still on the wing, as the honey stomach produces enzymes (酶) that break down the larger, complex sugar molecule (分子) into smaller ones.On arrival back at the hive, where bees live and work, the bee unloads the nectar by giving the sugary solution to other workers, who pass it back and forth between each other, adding more enzymes each time. Once it is sufficiently sticky, the mixture is laid down in the beeswax cells of the honeycomb and the workers continue the drying process by fanning it with their wings. Only when the water content has been reduced to about 18 percent (from about 75 percent in the original nectar) do they seal the cells with beeswax lids. At this point, it is well and truly honey.An average hive produces about 11 kg of honey in a season, which requires the bees to fly over 1.5 million kilometers between them. A standard jar of honey requires about 80,000 km. The effort that has gone into making honey is worth remembering when spreading it onto toast —it can surely only add to the pleasure.4.Why does the worker bee store the nectar in its stomach?A. To digest better.B. To absorb its nutrition.C. To keep it for its future food.D. To share it with other bees.5.What can be inferred from paragraph 3?A. The cells are sealed by sticky solution.B. Producing honey requires teamwork.C. The drying work is done by female bees.D. It’s critical to maintain water percentage.6.How is the last paragraph developed?A. By listing figures.B. By giving definitions.C. By making comparisons.D. By providing examples.7.Which may be a suitable title for the text?A. Skilled WorkersB. A Simple PleasureC. Advanced and Intelligent CreaturesD. Luxurious Sweetness from Delicate WorkCThe argument that human-caused carbon emissions(排放) are merely a drop in the bucket compared to greenhouse gases generated by volcanoes has been making its way around the rumor mill for years. And while it seems to be reasonable, the science just doesn't back it up.According to the US Geological Survey (USGS), the world's volcanoes, both on land and undersea, generate about 200 million tons of carbon dioxide (CO2) annually, while our automotive and industrial activities cause some 24 billion tons of CO2 emissions every year worldwide. Despite the arguments to the contrary, the facts speak for themselves: Greenhouse gas emissions from volcanoes compose less than one percent of those generated by today's human activities.Another indication that human emissions surpass those of volcanoes is the fact that atmospheric CO2 levels, as measured by sampling stations around the world, have gone up consistently year after year regardless of whether or not there have been major volcanic eruptions in specific years. “If it were true that individual volcanic eruptions dominated human emissions and were causing the rise ineach eruption,” says Coby Beck, a journalist writing for online environmental news. “Instead, such records show a smooth and regular trend.”Furthermore, some scientists believe that volcanic eruptions, like that of Mt. St. Helens in 1980 and Mt. Pinatubo in 1991, actually lead to short-term global cooling, not warming, as sulfur dioxide (SO2), ash and other particles in the air and stratosphere(平流层) reflect some solar energy instead of letting it into Earth's atmosphere. SO2, which converts to sulfuric acid aerosol, when it hits the stratosphere, can linger there for as long as seven years and can exercise a cooling effect long after a volcanic eruption has taken place.Scientists tracking the effects of the major 1991 eruption of the Philippines’ Mt. Pinatubo found that the overall effect of the blast was to cool the surface of the Earth globally by some 0.5 degrees Celsius a year later, even though rising human greenhouse gas emissions and an EI Nino event caused some surface warming during the 1991-1993 study period.In an interesting twist on the issue, British researchers last year published an article in the peer reviewed scientific journal Nature showing how volcanic activity may be contributing to the melting of ice caps in Antarctica but not because of any emissions, natural or man-made. Instead, scientistsHugh Corr and David Vaughan of the British Antarctic Survey believe that volcanoes underneath Antarctica may be melting the continents ice sheets from below, just as warming air temperatures from human-induced emissions erode them from above.8.According to Paragraph 1, some people argue that ______.A. their opinion is supported by science.B. volcanoes generate most of the greenhouse gases.C. human activities are to blame for greenhouse gases.D. carbon emissions produced by volcanoes are increasing.9.What does the underlined word "spikes" in Paragraph 3 probably mean?A. Sudden increases.B. Smooth trends.C. Stable regularities.D. Sharp declines.10.What do the scientists mentioned in this passage believe about volcanic eruptions?A. They brought about global warming.B. They actually partly cooled the surface of the Earth.C. They melted the ice sheets in Antarctic from above.D. They dominated human emissions in greenhouse effect.11.The purpose of the passage is to ______.A. compare the results of the studies.B. contradict a view held by some people.C. present new findings for greenhouse phenomenon.D. report the effects of CO2, in greenhouse phenomenon.DI was once a Chinese TV star. Actually, I'm neither Chinese nor a star, but for two seasons, I was the French voice of one of the major characters in a famous Chinese soap opera.China has put a lot of effort into sharing its culture with the world. Chinese movies and TV shows have been translated into various languages. As a result, dubbing (配音) jobs in China have increased greatly over the years.I landed my first dubbing job without having any previous experience, something that would be impossible in France. As I entered the tiny recording studio, I pretended to know how to dub, feelingmanaged to control my shaking hands, and tried my best to match the French text with the Chinese lips. Finally, they asked me to try again, with more emotion this time. And so I did. To my surprise, I secured my first role.Once I was in the database, I got offered roles every now and then. I really started enjoying the Chinese soap operas. As the shows helped me to better understand the Chinese family and the relationships between young people in China, I realized I was able to have deeper conversations with my Chinese friends.And so I discovered that dubbing is not a job that stays in the office; it becomes part of you. Not only because of what other people think, but because of what you share with the character. When my character once believed her mother had killed herself, I couldn’t help crying. I left the studio and immediately called my mom, and I believe that was the nicest call I ever made to her. This might sound silly, I know, but I will miss “her”. Our one-way relationship was as fictional as she was, but the emotions were real.12.Why did dubbing jobs in China increase quickly?A. China has various cultures to record.B. China has set up many cultural companies.C. China has developed very fast in recent years.D. China encourages TV shows to spread its culture.13.What does the underlined word “fraud” in paragraph 3 probably mean?A. Actress.B. Cheater.C. Foreigner.D. Director.14.What is the fourth paragraph mainly about?A. The author’s Chinese friends help her a lot.B. Soap operas spread Chinese culture widely.C. Dubbing in soap operas helps the author a lot.D. The author likes Chinese soap operas very much.15.What can be a suitable title for the text?A. My Dubbing Experience in ChinaB. Dubbing, an interesting jobC. Dubbing in ChinaD. My first success第二节(共5小题;每小题2.5分,满分12.5分)根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。
精品解析:北京市北京师范大学附属实验中学2024-2025学年七年级上学期期中英语试题(解析版)
北师大实验中学2024-2025学年度第一学期期中试卷初一年级英语班级________ 姓名________ 学号________ 成绩________考生须知:1.本试卷共12页,共十道大题,62道小题;答题纸共2页。
满分100分。
考试时间90分钟。
2.在试卷和答题卡上准确填写班级、姓名、学号。
3.试卷答案一律填写在答题卡上,在试卷上作答无效。
4.在答题卡上,选择题须用2B 铅笔将选中项涂黑涂满,其他试题用黑色字迹签字笔作答。
第一部分:听力理解(20分)一、听对话或独白,根据对话或独白的内容,从下面各题所给的A、B、C三个选项中选出最佳选项。
每段对话或独白你将听两遍。
(共12分,每小题1.5分)请听一段对话,完成第1至第2小题。
1. What color of the sweater does Dave like?A. Black.B. Red.C. Green.2. How much will the man pay for the sweater?A. 15 dollars.B. 20 dollars.C. 25 dollars.请听一段对话,完成第3至第4小题。
3. What does Jessica think of geography?A. Boring.B. Difficult.C. Interesting.4. When does Jessica have geography classes?A. On Wednesday and Thursday.B. On Wednesday and Friday.C. On Thursday and Friday.请听一段对话,完成第5至第6小题。
5. Where is the library?A. Next to the dining hall.B. Behind the dining hall.C. In front of the dining hall.6. Where are the speakers?A. At a cinema.B. At school.C. At a park.请听一段独白,完成第7至第8小题。
2024-2025学年八年级数学上学期期中模拟卷(深圳专用,北师大版八上第1~4章)(考试版A4)
2024-2025学年八年级数学上学期期中模拟卷(深圳专用)(考试时间:90分钟 试卷满分:100分)注意事项:1.答卷前,考生务必将自己的姓名、准考证号等填写在答题卡和试卷指定位置上。
2.回答选择题时,选出每小题答案后,用铅笔把答题卡上对应题目的答案标号涂黑。
如需改动,用橡皮擦干净后,再选涂其他答案标号。
回答非选择题时,将答案写在答题卡上。
写在本试卷上无效。
3.考试结束后,将本试卷和答题卡一并交回。
4.测试范围:北师大八上第一章勾股定理+第二章实数+第三章位置与坐标+第四章一次函数。
5.难度系数:0.70。
第一部分(选择题 共24分)一、选择题(本大题共8小题,每小题3分,满分24分.在每个小题给出的四个选项中,只有一项符合题目要求的)1.在实数 3.14,0,2p ,227,0.1616616661¼(两个1之间依次多一个6)中,无理数的个数是( )A .5B .4C .3D .22.下列二次根式中,是最简二次根式的是( )A B C D 3.如图,根据尺规作图痕迹,图中标注在点A 处所表示的数为( )A .B .1C .1-+D .1-4.三角形ABC 中,A Ð,B Ð,C Ð的对边分别记为a ,b ,c ,由下列条件不能判定三角形ABC 为直角三角形的是( )A .AB C=+∠∠∠B .::1:1:2A B C ÐÐÐ=C .222b a c =+D .::1:1:2a b c =5.已知点P 的坐标为()2,36a a -+,且点P 到两坐标轴的距离相等,则点P 的坐标是( )A .()3,3B .()3,3-C .()6,6-D .()3,3或()6,6-6.在同一平面直角坐标系中,一次函数2y ax a =+与2y a x a =+的图像可能是( )A .B .C .D .7.某数学兴趣小组开展了笔记本电脑的张角大小的实践探究活动.如图,当张角为BAF Ð时,顶部边缘B 处离桌面的高度BC 为7cm ,此时底部边缘A 处与C 处间的距离AC 为24cm ,小组成员调整张角的大小继续探究,最后发现当张角为DAF Ð时(D 是B 的对应点),顶部边缘D 处到桌面的距离DE 为20cm ,则底部边缘A 处与E 之间的距离AE 为( )A .15cmB .18cmC .21cmD .24cm8.如图,直线483y x =-+分别与x ,y 轴交于点A ,B ,点C 在线段OA 上,将BOC V 沿BC 翻折,点O 恰好落在AB 边上的点D 处.则点C 的坐标为( )A .8,03æöç÷èøB .5,03æöç÷èøC .()20,D .()30,第二部分(非选择题 共76分)二、填空题(本大题共5小题,每小题3分,满分15分)9的算术平方根为 .10.已知x 的整数部分,y xy 的值 .11.如图是勾股树衍生图案,它由若干个正方形和直角三角形构成,1S ,2S ,3S ,S ₄分别表示其对应正方形的面积,若已知上方左右两端的两个正方形的面积分别是64,9,则1234S S S S -+-的值为12.如图,已知等边AOC △的边长为1,作OD AC ^于点D ,在x 轴上取点1C ,使1CC DC =,以1CC 为边作等边11A CC △;作111CD A C ^于点1D ,在x 轴上取点2C ,使1211C C D C =,以12C C 为边作等边212A C C V ;作1222C D A C ^于点2D ,在x 轴上取点3C ,使2322C C D C =,以23C C 为边作等边323A C C △;…,且点123,,,A A A A ,…都在第一象限,如此下去,则点2023D 的坐标为 .13.数形结合是数学的重要思想和解题方法,如:“当012x <<值”可看作两直角边分别为x 和2的Rt ACP V 12x -和3的Rt BDP V 的斜边长.于是将问题转化为求AP BP +的最小值,如图所示,当AP 与BP 共线时,AP BP +为最小.请你解决问题:当04x <<的最小值是 .三、解答题(本大题共7小题,满分61分.解答应写出文字说明,证明过程或演算步骤)14.(8分)计算:(1)0(2023)1|p -+-(2)+-.15.(7分)已知2x +的一个平方根是2-,21x y +-的立方根是3;(1)求x y 、的值;(2)的算术平方根.16.(7分)如图,在平面直角坐标系中,△ABC 顶点分别是()0,2A ,()2,2B -,()4,1C -.(1)在图中作出△ABC 关于y 轴对称的111A B C △;(2)直接写出对称点坐标1B ________,1C ________;(3)在图中第一象限格点中找出点D ,使AD =且同时CD (无需计算过程,请把点画清楚一些)17.(8分)如图,在三角形ABC 中,90ABC Ð=°,20AC =,12BC =.(1)设点P 在线段AB 上,连接PC ,若PAC PCA Ð=Ð,求AP 的长;(2)设点M 在线段AC 上,若MBC △是等腰三角形,求AM 的长.18.(10分)综合与实践【问题情境】在平面直角坐标系中,有不重合的两点()11,A x y 和点()22,B x y ,若12x x =,则AB y ∥轴,且线段AB 的长度为12y y -:若12y y =,则AB x ∥轴,且线段AB 的长度为12x x -.【知识应用】(1)若点()1,1A -,()2,1B ,则AB x ∥轴,AB 的长度为________;【拓展延伸】我们规定:平面直角坐标系中,任意不重合的两点()11,M x y ,()22,N x y 之间的折线距离为()1212,d M N x x y y =-+-.例如:图1中,点()1,1M -与点()1,2N -之间的折线距离为()(),1112235d M N =--+--=+=.【问题解决】(2)如图2,已知()2,0E ,若()1,1F --,则(),d E F =________;(3)如图2,已知()2,0E ,()1,G t ,若(),3d E G =,则t 的值为________;(4)如图3,已知()2,0E ,()0,2H ,点P 是EOH △的边上一点,若(),d E P =P 的坐标.19.(10分)问题情境:在学习了《勾股定理》和《实数》后,某班同学们以“已知三角形三边的长度,求三角形面积”为主题开展了数学活动,同学们想到借助曾经阅读的数学资料进行探究:材料1.古希腊的几何学家海伦(Heron ,约公元50年),在他的著作《度量》一书中,给出了求其面积的海伦公式S =(其中a b c ,,为三角形的三边长,2a b c p ++=,S 为三角形的面积).S a b c ,,,三角形的面积为S .(1)利用材料1解决下面的问题:当3a b c ===,(2)利用材料2解决下面的问题:已知ABC V 24-,记ABC V 的周长为ABC C V .①当2x =时,请直接写出ABC V 中最长边的长度;②若x 为整数,当ABC C V 取得最大值时,请用秦九韶公式求出△ABC 的面积.20.(11分)如图,点(0,)A a ,点(,0)B b 分别为y 轴正半轴、x 轴负半轴上的点,以点B 为直角顶点在第二象限作等腰Rt ABC △.(1)如图1,若a 、b 满足()230a -=,求点C 的坐标;(2)在x 轴上是否存在点P ,使PAB V 是以AB 为腰的等腰三角形?若存在,请直接写出点P 的坐标;若不存在,请说明理由.(3)如图2,点M 在AC 上,点N 在CA 的延长线上,45MBN Ð=°,探究线段CM 、AN 和MN 之间的关系,并加以证明.。
2024-2025学年八年级上学期北师大版数学期中考试模拟试卷
2024-2025学年八年级上学期北师大版数学期中考试模拟试卷一、单选题1π,131.626626662……中,无理数的个数是()A .1个B .2个C .3个D .4个2.一次函数73y x =-的图象不经过的象限是()A .第一象限B .第二象限C .第三象限D .第四象限3.一等腰三角形,腰长10cm ,底长16cm ,则底边上的高是()A .8cmB .6cmC .10cmD .12cm4.已知a ,b ,c 是三角形的三边长,如果满足()26|10|0a c --=,则三角形的形状是()A .等腰三角形B .等边三角形C .钝角三角形D .直角三角形5.下列计算正确的是()A=B .3-=C =D .2=6.△ABC 的三边长分别为a ,b ,c ,由下列条件不能判断△ABC 是直角三角形的是()A .∠A =2∠B =3∠C B .∠A =∠C ﹣∠B C .a :b :c =12D .a 2=(b +c )(b ﹣c )7.一个正比例函数的图象经过()2,4A -,(),2B m -两点,则m 的值为()A .2-B .1-C .2D .18.在平面直角坐标系中,若点(231)P a +-,与点(51)Q b -,关于x 轴对称,则a b +的值是()A .1B .2C .3D .49.如图,Rt ABC △中,90ACB ∠=︒,以Rt ABC △的三边为边向外作正方形,其面积分别是1S ,2S ,3S ,且14S =,216S =,则3S =()A .20B .12C .D .10.如图,在平面直角坐标系xOy 中,O 为坐标原点,(4,0)A ,(4,2)B ,(0,2)C ,将OAB △沿直线OB 折叠,使得点A 落在点D 处,OD 与BC 交于点E ,则点D 的纵坐标为()A .165B .125C .95D .4二、填空题1115(填“>、<、或=”)12.若点(x 1,y 1)和(x 2,y 2)都在直线y =−3x +b 上,且x 1<x 2,则y 1、y 2的大小关系是.13.将直线y =﹣12x +6向下平移2个单位,平移后的直线分别交x 轴、y 轴于A 、B 两点,点O 为坐标原点,则S △ABO =.14.中国古代数学家们对于勾股定理的发现和证明,在世界数学史上具有独特的贡献和地位,体现了数学研究中的继承和发展.下图是3世纪我国汉代的数学家赵爽在注解《周髀算经》时给出的图案,人们称它为“赵爽弦图”.此图中四个全等的直角三角形可以围成一个大正方形,中空的部分是一个小正方形.如果大正方形的面积是25,小正方形的面积是1,则()2a b +的值是.15.实数a b ,||a b +化简结果为.16.已知-2<x<1化简的结果是.三、解答题17.计算:|4|+18.求下列各式中x 的值(1)()2419x +=;(2)()31342x +=-.19.已知2x -的平方根是2±,27x y ++的立方根是3,求22x y +的平方根.20.已知1x =-,1y =.()1求22x xy y ++;()2若a 是x 的小数部分,b 是y 的整数部分,求1ba b a-+的值.21.已知:在四边形ABCD 中,连接AC ,BC AB =,2222CD AD AB +=,AD CD ⊥.(1)试判断AB 与BC 的位置关系,并说明理由;(2)当13CD AB =,17AD =,求四边形ABCD 的周长.22.如图,一架云梯AB 斜靠在一竖直的墙AO 上,这时20AO =米,云梯AB 的长度比OB 的长度(云梯底端离墙的距离)大10米,AO BO ⊥,设OB 的长度为x 米.(1)求OB 的长度;(2)若云梯的顶端A 沿墙下滑了5米到达点C 处,通过计算说明云梯的底部B 往外移动多少米.23.学校首届海棠文化节启动暨原创校园歌曲《京广路86号》现场发布仪式于4月2日在京广校区举行,海棠文化节系列活动也伴随启动仪式同步开展.为奖励积极参与活动的班级与个人,学校计划购买A 、B 两种奖品,若购买A 种奖品3个和B 种奖品2个共需要130元;若购买A 种奖品5个和B 种奖品4个共需要230元.(1)A 、B 两种奖品的单价;(2)按照学校计划,准备购买A 、B 两种奖品共20个,且A 种奖品的数量不少于B 种奖品的数量的2倍,请你设计出最省钱的购买方案,并说明理由.24.如图,直线24y x =-+交x 轴和y 轴于点A 和点B ,点(0,2)C -在y 轴上,连接AC .(1)求直线AC 的解析式;(2)若点P 是直线AB 上一点,若BPC 的面积为3,求点P 的坐标;(3)在x 轴上是否存在一点D ,使得ABD △是等腰三角形,若存在,请直接写出点D 坐标,若不存在,请说明理由.25.如图1,已知直线24y x =+与y 轴,x 轴分别交于A ,B 两点,以B 为直角顶点在第二象限作等腰Rt ABC △.(1)求点C 的坐标,并求出直线AC 的关系式;(2)如图2,直线CB 交y 轴于E ,在直线CB 上取一点D ,连接AD ,若AD AC =,求证:BE DE =;(3)如图3,在(1)的条件下,直线AC 交x 轴于点M ,7,2P a ⎛⎫- ⎪⎝⎭是线段BC 上一点,在x轴上是否存在一点N ,使BPN △面积等于BCM 面积的一半?若存在,请求出点N 的坐标;若不存在,请说明理由.。
北师大版2019-2020学年八年级下学期语文期末考试试卷B卷精版
北师大版2019-2020学年八年级下学期语文期末考试试卷B卷姓名:________ 班级:________ 成绩:________一、选择题 (共2题;共4分)1. (2分)下列划线成语使用不正确的一项是()A . 当改革的浪潮以摧枯拉朽之势席卷旧的司法鉴定制度时,我国司法鉴定的一个新的时代拉开了序幕。
B . 那些对自己的事业有探索精神并乐此不疲的人,最终都走向了成功。
C . 侦探小说中眼花缭乱的情节让我一头雾水,完全忘记了如何思考。
D . 家风是一种“软约束”,通过潜移默化的影响,实现对家庭成员行为、作风、操守的有效约束。
2. (2分)下列句子中没有语病的一项是()A . 近几年,国产奶粉的质量问题频发,从客观上推进了我国消费者对“洋奶粉”的依赖心理,使得“洋奶粉”格外受宠。
B . 望着白云缭绕的巍巍香炉峰和飞流直下、势不可挡的庐山瀑布,无不使游览者感受到大自然的壮美雄奇和神功伟力。
C . 国家有关部门组织核安全方面的专家,用9个月时间对在建核电机组、待建核电机组及核燃料循环设施等进行了安全检查。
D . 中学生之所以喜欢网络小说的原因,在于这些作品大多思想情感丰富细腻,人物形象栩栩如生,而且叙述方式自由活泼。
二、句子默写 (共1题;共5分)3. (5分) (2019七上·阳江月考) 根据课文默写古诗文。
(1)生活中表示既善于从正面学习,也善于从反面借鉴的意思时,我们常引用《论语》中的话:________,________。
(2)儒家经典让我们获益匪浅。
《论语》中的“________,________?”常用来表达当别人不了解甚至误解自己时应当采取的正确态度。
(3)孔子在《论语·述而》中论述君子对富贵的正确态度是:________,________。
(4)每年一度的亚洲博鳌论坛,华夏儿女喜迎各国嘉宾,我们可以引用《论语》中的“________,________?”来诠释这份情怀。
山东省枣庄市滕州市滕州育才中学2024-2025学年九年级上学期北师大版数学期中考试模拟卷
山东省枣庄市滕州市滕州育才中学2024-2025学年九年级上学期北师大版数学期中考试模拟卷一、单选题1.中国结寓意团圆、美满,以独特的东方神韵体现中国人民的智慧和深厚的文化底蕴.如图小陶家有一个中国结装饰,可以近似看作菱形ABCD ,测得12cm BD =,16cm AC =,则此菱形周长为()A .28cmB .40cmC .56cmD .80cm2.如图,菱形ABCD 对角线AC 与B 交于点O ,16,12AC BD ==,则菱形的面积为()A .48B .96C .24D .63.如图,在矩形ABCD 中,4AB =,对角线AC 与BD 相交于点O ,AE OB ⊥于点E ,当E 为OB 中点时,则AC 的长为()A .B .4C .D .84.如图,在正方形ABCD 中,边长为2的等边三角形AEF 的顶点E 、F 分别在BC 和CD 上,下列结论:①CE =CF ;②∠AEB =75°;③BE +DF =EF ;④S正方形ABCD =2正确的序号是()A .①②③B .②③④C .①③④D .①②④5.下列说法不正确的是()A .有一组邻边相等的平行四边形是菱形B .有一个角是直角的平行四边形是矩形C .有一组邻边相等且有个角是直角的平行四边形是正方形D .对角线相等的四边形是矩形6.下列方程是关于x 的一元二次方程的是()A .20ax bx c ++=B .210x -=C .2110x x +-=D .2220x y +-=7.“国庆节”和“中秋节”双节期间,某微信群规定,群内的每个人都要发一个红包,并保证群内其他人都能抢到且自己不能抢自己发的红包,若此次活动,群内所有人共收到156个红包,则该群一共有()人.A .12B .13C .14D .158.在一次同学聚会上,大家一见面就相互握手(每两人只握一次).大家共握了21次手.设参加这次聚会的同学共有x 人,根据题意,可列方程为()A .()121x x +=B .()11212x x +=C .()121x x -=D .()11212x x -=9.在一个不透明的盒子中,装有绿色、黑色、白色的小球共有60个,除颜色外其他完全相同,一同学通过多次摸球试验后发现其中摸到绿色球、黑色球的频率稳定在30%和40%,盒子中白色球的个数可能是()A .24个B .18个C .16个D .6个10.如图,数学活动课上,为测量学校旗杆高度,小菲同学在脚下水平放置一平面镜,然后向后退(保持脚、镜和旗杆底端在同一直线上),直到她刚好在镜子中看到旗杆的顶端.已知小菲的眼睛离地面高度为1.6m ,同时量得小菲与镜子的水平距离为2m ,镜子与旗杆的水平距离为10m ,则旗杆高度为()A .6.4mB .8mC .9.6mD .12.5m二、填空题11.如图,在菱形ABCD 中,对角线AC BD 、相交于点O ,点M N 、分别是边AD CD 、的中点,连接MN OM 、.若3MN =,24ABCD S =菱形,则OM 的长为.12.如图,已知菱形ABCD 的对角线AC ,BD 相交于点O .若6AC =,BD =,则DAB ∠的度数是.13.如图,已知点E ,F 分别在正方形ABCD 的边BC ,CD 上,45EAF ∠=︒,且4:9:AEF ABCD S S =正方形 ,则:AB EF =.14.若()1||140a a x -+-=是关于x 的一元二次方程,则a 的值为.15.如图,小雅同学在利用标杆BE 测量建筑物的高度时,测得标杆BE 高1.2m ,又知AB :BC =1:8,则建筑物CD =.16.如图,已知ABC V 中,8AB =,7BC =,6AC =,E 是AB 的中点,F 是AC 边上一个动点.将AEF △沿EF 折叠,使点A 落在A '处,如果AEF △与原ABC V 相似,那么EF 的长为.三、解答题17.如图,在四边形ABCD 中,AD ∥BC ,∠B=90°,AB=8cm ,AD=16cm ,BC=22cm ,点P 从点A 出发,以1cm/s 的速度向点D 运动,点Q 从点C 同时出发,以3cm/s 的速度向点B 运动,其中一个动点到达端点时,另一个动点也随之停止运动,设运动时间为t 秒.(1)当t 为多少时,四边形ABQP 成为矩形?(2)四边形PBQD 是否能成为菱形?若能,求出t 的值;若不能,请说明理由,并探究如何改变Q 点的速度(匀速运动),使四边形PBQD 在某一时刻为菱形,求点Q 的速度.18.如图,在四边形ABCD 中,90BAC ∠=︒,点E 是BC 的中点,AD BC ∥,AE DC EF CD ⊥ ,于点F .求证:四边形AECD 是菱形;19.已知关于x 的方程2²440x x k -+-=(k 为常数).(1)求证:不论k 取何值时,该方程总有实数根.(2)方程的两个实数根可能都是负根吗?判断并说明理由.20.已知关于x 的方程220x ax a ++-=,问:(1)求证:不论a 取何实数,该方程都有两个不相等的实数根;(2)若该方程的两个根为12,x x ,且满足22124x x +=,求a 的值.21.如图1,已知40AB BC CD ++=.(1)若10AB CD ==,则BC =,矩形ABCD 的面积·AB BC ==⨯200=;(2)若AB CD x ==,则BC =,矩形ABCD 的面积·AB BC ==;(3)如图2,现有长度100米的围栏,要利用一面墙(墙长为25米)建羊圈,BC 的长度不大于墙长.围成总面积为400平方米的三个大小相同的矩形羊圈,求羊圈的边长AB BC ,各为多少米?22.某商店销售一种商品,平均每周可售出20件,每件利润60元.为了增加利润,商店准备适当降价,若此商品每降价1元,平均每周将多售出2件,考虑到运营过程中其它成本,此商品利润不得低于30元.(1)若要使每周销售利润达到1650元,则此商品每件需要降价多少元?(2)请问该商品每周的销售利润能达到2000元吗?请说明理由.23.2018年东营市教育局在全市中小学开展了“情系疏勒书香援疆”捐书活动,200多所学校的师生踊跃参与,向新疆疏勒县中小学共捐赠爱心图书28.5万余本.某学校学生社团对本校九年级学生所捐图书进行统计,根据收集的数据绘制了下面不完整的统计图表.请你根据统计图表中所提供的信息解答下列问题:图书种类频数(本)频率名人传记175a 科普图书b 0.30小说110c 其他65d(1)求该校九年级共捐书多少本;(2)统计表中的a=,b=,c=,d=;(3)若该校共捐书1500本,请估计“科普图书”和“小说”一共多少本;(4)该社团3名成员各捐书1本,分别是1本“名人传记”,1本“科普图书”,1本“小说”,要从这3人中任选2人为受赠者写一份自己所捐图书的简介,请用列表法或树状图求选出的2人恰好1人捐“名人传记”,1人捐“科普图书”的概率.24.如图,在ABC V 中,D ,E 分别是边AB ,连接DE ,且ADE ACB ∠=∠.(1)求证:ADE ACB ∽;(2)如果E 是AC 的中点,8,10AD AB ==,求AE25.已知:如图,在菱形ABCD 中,点E 、F 分别在边AB 、AD 上,BE =DF ,CE 的延长线交DA 的延长线于点G ,CF 的延长线交BA 的延长线于点H .(1)求证:△BEC ∽△BCH ;(2)如果BE 2=AB •AE ,求证:AG =DF .。
24-25学年九年级数学期中测试卷(北师大版)(考试版)【测试范围:第一章~第四章】A4版
2024-2025学年九年级数学上学期期中测试卷(北师大版)(考试时间:120分钟 试卷满分:120分)注意事项:1.本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分。
答卷前,考生务必将自己的姓名、准考证号填写在答题卡上。
2.回答第Ⅰ卷时,选出每小题答案后,用2B 铅笔把答题卡上对应题目的答案标号涂黑。
如需改动,用橡皮擦干净后,再选涂其他答案标号。
写在本试卷上无效。
3.回答第Ⅱ卷时,将答案写在答题卡上。
写在本试卷上无效。
4.测试范围:第一章~第四章(北师大版)。
5.考试结束后,将本试卷和答题卡一并交回。
第Ⅰ卷一、单项选择题(本题共10小题,每小题3分,共30分。
在每小题给出的四个选项中,只有一项是符合题目要求的。
)1.(3分)用配方法解一元二次方程2x 2﹣2x ﹣1=0,下列配方正确的是( )A .(x ―14)2=34B .(x ―14)2=32C .(x ―12)2=34D .(x ―12)2=322.(3分)如图,AB ∥CD ∥EF ,AF 交BE 于点G ,若AC =CG ,AG =FG ,则下列结论错误的是( )A .DG BG =12B .CD EF =12C .DG BE =13D .CG CF =133.(3分)如图,菱形ABCD 的对角线AC ,BD 相交于点O ,过点A 作AE ⊥BC 于点E ,连接OE .若OB =6,菱形ABCD 的面积为54,则OE 的长为( )A .4B .4.5C .5D .5.54.(3分)已知关于x 的一元二次方程(m ﹣1)x 2+2x ﹣3=0有实数根,则m 的取值范围是( )A .m ≥23B .m <23C .m >23且m ≠1D .m ≥23且m ≠15.(3分)下列说法正确的是( )A .邻边相等的平行四边形是矩形B .矩形的对角线互相平分C .对角线互相垂直的四边形是菱形D .一组对边相等,另一组对边平行的四边形是平行四边形6.(3分)在第十九届亚运会中国国家象棋队选拔赛的第一阶段中,采用分组单循环(每两人之间都只进行一场比赛)制,每组x 人.若每组共需进行15场比赛,则根据题意可列方程为( )A .12x (x ﹣1)=15B .12x (x +1)=15C .x (x ﹣1)=15D .x (x +1)=157.(3分)掷一个骰子,向上一面的点数大于2且小于5的概率为p 1,抛两枚硬币,正面均朝上的概率为p 2,则( )A .p 1<p 2B .p 1>p 2C .p 1=p 2D .不能确定8.(3分)顶角为36°的等腰三角形我们把这种三角形称为“黄金三角形”,它的底与腰的比值为黄金比.如图,在△ABC 中,∠A =36°,AB =AC ,BD 平分∠ABC 交AC 于点D ,若CD =1,则AC 的长为( )A B C D 9.(3分)如图,在平面直角坐标系中,四边形OABC 为矩形,且A (0,2),C (4,0).点E 为OC 上一点,连接AE ,射线AF ⊥AE .以点A 为圆心,适当长为半径作弧,分别交AE ,AF 于点N ,M ,再分别以点M ,N 为圆心,大于12MN 的长为半径作弧,两弧交于点P ,作射线AP ,交BC 于点G .若OE =1,则点G 的坐标为( )A .(4,23)B .(4,1)C .(4D .(410.(3分)如图,在正方形ABCD 中,点E 是CD 上一点,延长CB 至点F ,使BF =DE ,连结AE ,AF ,EF ,EF 交AB 于点K ,过点A 作AG ⊥EF ,垂足为点H ,交CF 于点G ,连结HD ,HC .下列四个结论:①AH =HC ;②HD =CD ;③∠FAB =∠DHE ;④AK •HD =2.其中正确结论的个数为( )A .1个B .2个C .3个D .4个第II 卷二、填空题(本题共6小题,每小题3分,共18分.)11.(3分)若x y =23,则代数式x―y x+2y 的值是 .12.(3分)在一个不透明的袋子中,有除颜色外完全相同的6个白球和若干个红球.通过大量重复摸球试验后,发现摸到红球的频率稳定在0.4,由此可估计袋中红球的个数为 .13.(3分)设α,β是x 2+x ﹣18=0的两个实数根,则α2+3α+2β的值是 .14.(3分)菱形有一个内角为120°,较长的对角线长为,则它的面积为 .15.(3分)如图,在△ABC中,E是BC上一点,EC=2BE,点F是AC的中点,若S△ABC=12,求S△ADF ﹣S△BED= .16.(3分)如图,在边长为4的菱形ABCD中,∠ABC=120°,将△ADC沿射线AC的方向平移得到△A'D'C',分别连接A'B,D′B,则A'B+D′B的最小值为 .三、解答题(本题共8小题,共72分.第17-18题每题6分,第19-20题每题8分,第21-22题每题10分,第23-24题每题12分,解答应写出文字说明、证明过程或演算步骤.)17.(6分)解方程:(1)x2﹣4x+2=0;(2)3(x﹣5)2+2(x﹣5)=0.18.(6分)小华和小林想用标杆来测量如图1所示的古塔的高,如图2,小林在F处竖立了一根标杆EF,小华走到C处时,站立在C处恰好看到标杆顶端E和塔的顶端B在一条直线上,此时测得小华的眼睛到地面的距离DC=1.5米,EF=2.4米,CF=1.8米,FA=71.2米,点C、F、A在一条直线上,CD⊥AC,EF⊥AC,AB⊥AC,根据以上测量数据,请你求出该塔的高AB.19.(8分)如图,在平面直角坐标系中,已知△ABC的三个顶点坐标分别是A(2,﹣1),B(1,﹣2),C(3,﹣3).(1)将△ABC向上平移4个单位长度,得到△A1B1C1;(点A、B、C分别对应A1、B1、C1)(2)以原点O为位似中心,在第二象限将△ABC放大得到△A2B2C2,使得△ABC与△A2B2C2的位似比为12,并直接写出C2的坐标.20.(8分)如图,BD是△ABC的角平分线,过点D作DE∥BC交AB于点E,DF∥AB交BC于点F.(1)求证:四边形BEDF为菱形;(2)如果∠A=90°,∠C=30°,BD=12,求菱形BEDF的边长.21.(10分)某校为落实“双减”工作,增强课后服务的吸引力,充分用好课后服务时间,为学有余力的学生拓展学习空间,成立了5个活动小组(每位学生只能参加一个活动小组):A.音乐;B.体育;C.美术;D.阅读;E.人工智能.为了解学生对以上活动的参与情况,随机抽取部分学生进行了调查统计,并根据统计结果,绘制了如图所示的两幅不完整的统计图.根据图中信息,解答下列问题:(1)①此次调查一共随机抽取了 名学生;②补全条形统计图(要求在条形图上方注明人数);③扇形统计图中圆心角α= 度;(2)若该校有1600名学生,估计该校参加D组(阅读)的学生人数;(3)学校计划从E组(人工智能)的甲、乙、丙、丁四位学生中随机抽取两人参加市青少年机器人竞赛,请用树状图法或列表法求出恰好抽中甲、乙两人的概率.22.(10分)根据以下销售情况,解决销售任务.销售情况分析总公司将一批衬衫由甲、乙两家分店共同销售,因地段不同,它们的销售情况如下:店面甲店乙店每天可售出20件,每件盈利40元.每天可售出32件,每件盈利30元.日销售情况市场调查经调查发现,每件衬衫每降价1元,甲、乙两家店一天都可多售出2件.情况设置设甲店每件衬衫降价a元,乙店每件衬衫降价b元.任务解决任务1甲店每天的销售量 (用含a的代数式表示).乙店每天的销售量 (用含b的代数式表示).任务2当a=5,b=4时,分别求出甲、乙店每天的盈利.任务3总公司规定两家分店下降的价格必须相同,请求出每件衬衫下降多少元时,两家分店一天的盈利和为2244元.23.(12分)阅读下面材料:小元遇到这样一个问题:如图1,在正方形ABCD中,点E、F分别为DC、BC边上的点,∠EAF =45°,连结EF,设DE=a,EF=b,FB=c,则把关于x的一元二次方程ax2﹣bx+c=0叫做正方形ABCD的关联方程,正方形ABCD叫做方程ax2﹣bx+c=0的关联四边形.探究方程ax2﹣bx+c=0是否存在常数根t.小元是这样思考的:要想解决这个问题,首先应想办法把这些分散的线段集中到同一条线段上.他先后尝试了平移、翻折、旋转的方法,发现通过旋转可以解决此问题.他的方法是把△ADE绕点A顺时针旋转90°得到△ABG(如图2),此时GF即是DE+BF.请回答:t= .参考小元得到的结论和思考问题的方法,解决下列问题:(1)如图1,若AD=10,DE=4,则正方形ABCD的关联方程为 ;(2)正方形ABCD的关联方程是2x2﹣bx+3=0,则正方形ABCD的面积= .24.(12分)教材再现:(1)如图1,在矩形ABCD中,AB=3,AD=4,P是AD上不与A和D重合的一个动点,过点P 分别作AC和BD的垂线,垂足分别为E,F,则PE+PF的值为 .知识应用:(2)如图2,在矩形ABCD中,点M,N分别在边AD,BC上,将矩形ABCD沿直线MN折叠,使点D恰好与点B重合,点C落在点C1处,点P为线段MN上一动点(不与点M,N重合),过点P分别作直线BM,BC的垂线,垂足分别为E和F,以PE,PF为邻边作平行四边形PEQF,若DM=13,CN=5,▱PEQF的周长是否为定值?若是,请求出▱PEQF的周长;若不是,请说明理由.(3)如图3,当点P是等边△ABC外一点时,过点P分别作直线AB、AC、BC的垂线、垂足分别为点E、D、F.若PE+PF﹣PD=3,请直接写出△ABC的面积.。
八年级数学期中模拟卷(考试版A4)【测试范围:北师大版八年级上册第1章-第4章】(河南专用)
2024-2025学年八年级数学上学期期中模拟卷(河南专用)(考试时间:100分钟 试卷满分:120分)注意事项:1.本试卷分第Ⅰ卷(选择题)和第Ⅱ卷(非选择题)两部分。
答卷前,考生务必将自己的姓名、准考证号填写在答题卡上。
2.回答第Ⅰ卷时,选出每小题答案后,用2B 铅笔把答题卡上对应题目的答案标号涂黑。
如需改动,用橡皮擦干净后,再选涂其他答案标号。
写在本试卷上无效。
3.回答第Ⅱ卷时,将答案写在答题卡上。
写在本试卷上无效。
4.测试范围:北师版八年级上册第1章-第4章。
5.难度系数:0.75。
第I 卷一、选择题:本题共10小题,每小题3分,共30分。
在每小题给出的四个选项 中,只有是一项符合题目求的1.使代数式有意义的x 的取值范围是( )A .x≥0B .﹣5≤x <5C .x≥5D .x≥﹣52.下列各数中,是无理数的是( )A .0B .227C D .3 )A .2B .C .-D .±4.若点(,)P a b 在第二象限内,则(,)P a b -在( )A .第一象限B .第二象限C .第三象限D .第四象限5.下列计算正确的是( )A B .C D6.已知点()12y -,,()23y ,都在直线y x b =-+上,则1y 与2y 的大小关系是( )A .12y y <B .12y y =C .12y y >D .无法确定71+最接近的整数是( )A.5B.4C.3D.28.一个直角三角形有两条边分别是3cm,4cm,则第三条边的长度是()A.5cm B cm C.5cm cm D.以上都不对9.毕达哥拉斯树也叫“勾股树”,是由毕达哥拉斯根据勾股定理所画出来的一个可以无限重复的树状图形,其中所有的四边形都是正方形,所有的三角形都是直角三角形.如图,若正方形A,B,C,D的边长分别是2,3,1,2,则正方形G的边长是()A.8B.C.D.510.大年三十晚上,小六驾车从家出发到烟花燃放指定点去燃放烟花炮竹,小六驾车匀速行驶一段时间后,途中遇到堵车原地等待一会儿,然后小六加快速度继续匀速行驶,零点之前到达指定燃放地点,燃放结束后,小六驾车匀速返回.其中,x表示小六从家出发后所用时间,y表示小六离家的距离.下面能反映y与x的函数关系的大致图象是( )A.B.C.D.第II卷二、填空题:本题共5小题,每题3分,共15分。
