江苏省常熟中学2019-2020学年高(2)
2019-2020学年江苏省苏州市常熟市高一(下)期中数学试卷
由一个样本 , , , , 的平均数为 ,
所以 ;
又不等式 的解集为 ,
所以 ,
解得 = ,
所以 = ;
所以该样本的方差为: = ;
标准差为 .
8.已知直线 : = 和圆 = ,给出下列说法:
①直线 和圆 不可能相切;
②当 = 时,直线 平分圆 的面积;
③若直线 截圆 所得的弦长最短,则 ;
∵ 圆心到直线 = 的距离 ,
则直线 = 被圆 = 截得的弦长为 .
但当直线 截圆 所得的弦长为 时,只有一个 的取值,使直线 截圆 所得的弦长为 ,故④错误.
∴ 其中正确的说法个数是 个.
二、多项选择题(本大题共4小题,每小题5分,共计20分.在每小题给出的四个选项中,至少有两个是符合题目要求的,请把答案添徐在答题卡相应位置上)
对于 ,一条直线的倾斜角为 时,它的斜率为 或不存在, 错误.
一个人连续射击 次,则下列各事件关系中,说法正确的是( )
A.事件“两次均击中”与事件“至少一次击中”互为对立事件
B.事件“第一次击中”与事件“第二次击中”互为互斥事件
C.事件“恰有一次击中”与事件“两次均击中”互为互斥事件
D.事件“两次均未击中”与事件“至少一次击中”互为对立事件
【解答】
∵ = , = , ,
∴ 可得: = ,
∵ = = = ,可得: = ,
∴ .
7.样本 , , , , 的平均数为 ,且不等式 的解集为 ,则这个样本的标准差是( )
A. B. C. D.
【答案】
A
【考点】
极差、方差与标准差
【解析】
由平均数定义和根与系数的关系求出 和 ,再计算该样本的方差和标准差.
2019-2020学年苏州市常熟中学高一(下)期末物理试卷(含答案解析)
2019-2020学年苏州市常熟中学高一(下)期末物理试卷一、单选题(本大题共23小题,共69.0分)1.一质点在恒力作用下沿曲线abc从a运动到c,已知质点的速率是递减的.关于质点在b点的受力的方向,下列图示中可能正确的是(虚线是曲线在b点的切线)()A. B. C. D.2.一大小固定的正三角形ABC在纸平面内运动,某时刻A点的速度v1恰沿AB方向,C点的速度v2方向恰垂直于AB,如图所示,则v1与v2在大小之比必等于()A. √33B. √32C. √3D. 23.如图所示,物体在恒力F作用下沿曲线从A运动到B,这时,突然使它受力反向,大小不变,若BD为曲线AB在B点的切线方向,则该物体()A. 可能沿曲线BE运动B. 可能沿曲线BD运动C. 可能沿曲线BC运动D. 一定是做匀变速直线运动4.在空间中水平面MN的下方存在竖直向下的匀强电场,质量为m的带电小球由MN上方A点以一定初速度v 0水平抛出,从B点进入电场,到达C点时速度方向恰好水平,A、B、C三点在同一直线上,且,如图所示。
已知重力加速度为g,则A. 电场力大小为2mgB. 小球带正电C. 小球从A到B与从B到C的运动时间相等D. 小球从A到B与从B到C的速度变化量的大小相等5.A,B两个质点分别做匀速圆周运动,在相等时间内通过的弧长之比s A:s B=4:3,转过的圆心角之比θA:θB=3:2,则下列说法中正确的是()A. 它们的线速度之比v A:v B=4:3B. 它们的角速度之比ωA:ωB=2:3C. 它们的周期之比T A:T B=3:2D. 它们的向心加速度之比a A:a B=3:26.一质量为m的物块恰好静止在倾角为θ的斜面上.则斜面对物体的作用力方向为()A. 沿斜面向上B. 垂直斜面向上C. 竖直向上D. 垂直斜面向下7.如图所示,一个光滑的圆环M,穿着一个小圈N,圆环M以竖直的AOB轴为转轴,做匀速转动()A. 圈N所受的力是圈的重力、环对圈的摩擦力B. 圈N所受的力是圈的重力、圈的向心力C. 圈N的向心力方向是垂直指向转轴D. 圈N的向心力方向是指向圆环圆心O8.已知地球质量为M,半径为R,自转周期为T,地球同步卫星质量为m,引力常量为G.有关同步卫星,下列表述正确的是()A. 卫星距离地面的高度为3GMT24π2B. 卫星的运行速度小于第一宇宙速度C. 卫星运行时受到的向心力大小为G MmR2D. 卫星运行的向心加速度大于地球表面的重力加速度9.“太空110−轨道康复者”可以对卫星在太空中补充能源,使卫星的寿命延长10年或更长。
江苏省常熟中学2019-2020学年度第二学期高三5月学情检测练习英语试题 含答案
江苏省常熟中学2019-2020学年第二学期5月学情检测高三英语试卷(本试卷共120分,考试时间120分钟)第I卷(选择题三部分共85分)第一部分听力(共两节,满分20分)第一节(共5小题;每小题1分,满分5分)听下面5段对话。
每段对话后有一个小题,从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. Who is the man possibly talking to?A. A doctor.B. A teacher.C. His mother2. What do we know about Sam?A. His sister will leave for New York.B. His sister will leave for Los Angeles.C. He will leave New York.3. What is the woman going to do?A. Rewrite the paper because there are too many mistakes.B. Throw the paper away.C. Read the paper again.4. Why does the woman thank the man?A. He lent her some money.B. He gave her a five-pound bill.C. He returned her money found.5. Where does this conversation probably take place?A. At an airport.B. At a railway station.C. At a department store.第二节(共15小题;每小题1分,满分15分)听下面5段对话或独白。
2019-2020学年江苏省常熟中学高三英语第二次联考试题及参考答案
2019-2020学年江苏省常熟中学高三英语第二次联考试题及参考答案第一部分阅读(共两节,满分40分)第一节(共15小题;每小题2分,满分30分)阅读下列短文,从每题所给的A、B、C、D四个选项中选出最佳选项AGetting your kid to bed at night is seriously one of the most challenging things you'll ever have to do. Most kids are just so full of energy that they'll tire you out before they're halfway through their store of energy. An easy thing to calm down your child to get into bed is giving in and allowing some iPad screen time. However, it's really not a great idea, just like you thought.Researchers at theArizonaStateUniversityconducted a study with 547 kids between the ages of 7 to 9. Their parents tracked how much screen time the kids were allowed along with their sleep patterns. The study found that kids who did not engage in screen time before bed slept for 23 more minutes every week and also went to sleep about 34 minutes earlier than those playing with iPad. Although that might not seem like so much more time, quality of sleep is vastly important in Children's development.The CDC's (美国疾病控制中心)2018 National Youth Risk Survey outlines that good quality sleep can impact a child's life in many ways, including affecting grades and also weight gain. Students with an "A" average slept for 30 or more minutes per night than those with a "D" or"F" average.A 2018PennsylvaniaStateUniversitystudy showed that children with irregular bedtimes had a higher risk of having increased body weight. Those with consistent and age-appropriate bedtimes when they were 9 years old had a healthier BMI (体质指数)at age 15 than those with irregular bedtimes.Hard as it is, it's really important not to give in and hand over an iPad to your child who is about to go to bed. Just like it's important for adults to go to sleep without any distractions, it's even more important for kids.1. What do the findings of the researchers at theArizonaStateUniversitysuggest?A. More sleep is necessary for children's development.B. Enough sleep helps improve academic performances.C. Screen time before bed leads to later and less sleep.D. Children sleeping irregularly are easy to gain weight.2. What is the text mainly about?A. How is screen time affecting teenagers?B. What are negative effects of irregular bedtimes?C. When should you get your kid to bed at night?D. Why is screen time before bed a bad idea for kids?3. Who is the text intended for?A. Parents.B. Children.C. Teachers.D. Researchers.BWhen Chip heard the mail truck arriving on his sixth birthday, herushed out—not knowing that he’d come back with a treasure.Outside the house, which was decorated with birthday balloons, postwoman Shelley held a pile of boxes. One was marked with Chip’s name and a greeting for his Special day, November 5.“So,” when he came running out the door, she said, “You must be Chip!” And he said,“Yes.” She said, “Today’s your birthday?” And he started smiling. Shelley said, “So, let me see if I can find you something for your birthday.”She checked her pocket and surprised him with a gift: a dollar bill and four quarters.On this day, the 42-year-old postwoman made one little boy very happy. “He was very excited,” said his mom, Bonnie. “He came running back in the house just waving his money.” Chip is saving up to buy a Spider-man action figure.“Our family has had money problems since I lost my job. Gestures like that are valuable memories.” Her hope is that Chip and his eight-year-old sister, Bennett, will remember this when they grow up. “Not the ugly that is out there right now, but the good and the kind and the giving.”A photo of a smiling Chip and Shelley next to the mail truck has been shared widely on social media. Shelley said she was just trying to give back, because people are often nice to her eight-year-old son, Joshua.On a recent day, Chip heard the mail truck and rushed out again, this time to deliver an envelope with a thank-you card for his favorite mail carrier. Since that day, the families have kept in contact. Shelley has struggled to find someone who can take care of her son, and Bonnie has agreed to watch him at her home while his mom is on her mail route.4. Why did Chip rush out when he heard the mail truck the first time?A. To thank the postwoman.B. To get a gift box mailed to him.C. To receive birthday wishes from the driver.D. To watch the mail truck.5. What did Shelley do to make Chip happy?A. She gave him some pocket money.B. She sent him some birthday balloons.C. She presented him with a greeting card.D. She bought him a Spider-man action figure.6. What is Chip’s mother’s attitude towards Shelley?A. Grateful.B. Curious.C. Doubtful.D. Indifferent.7. What does Chip’s mother do to help Shelley?A. She offers to deliver the mails for her.B. She often helps drive her mail truck.C. She looks after her son when she is at work.D. She posts pictures of her mail truck on social media.CIt is essential that students have a category of school-related activities they can participate in. These activities can range from activities during normal school hours to after-school activities. No matter the time, these activities should be available to every student, and at Victory Pioneers International Schools (V.P.I.S) it is encouraged that every student participate in at least one activity, educational and recreational.One of the primary reasons school activities are important at V.P.I.S. is because it gives students the exercise they might not normally receive. Most popularly, these types of activities include major sports such as football, basketball, baseball, tennis, track and field and soccer but also might include gymnasium games and other games.Activities during V.P.I.S. also make a good impression on colleges if students are planning to pursue more education. Colleges look for students who do not just go to school and go home after school. These activities range from participating in clubs and sports to volunteering after school at a recreation center or having a part-time job. If a college sees you maintained good grades while participating in these activities, it will be impressed.V.P.I.S. activities also allow students to be creative. Gifted-and-talented activities allow gifted students to participate in what they otherwise would never have experienced in the classroom. They are a great way to allow students to be creative. Additionally, participating in clubs such as drama that appeal to students’ interest also allows them to expand their knowledge and be creative.Students also can have their interests expanded by participating in activities. These activities could consist of anything, such as joining the Future Business Leaders, the school’s debate team and the chess team, to name afew. By participating in these activities, a student might realize he is interested in something he never knew he was interested in before.8. What can we learn about activities at V.P.I.S.?A. Not every student has access to them.B. Students are required to take part in them after school.C. They give students exercise that might not be got in other schools.D. Educational activities are more popular with the students.9. What benefits can the students get from the activities?A. They can get extra grades when applying for colleges.B. They will become more gifted and talented .C. They may expand their knowledge in drama.D. They may better know their own interests.10. Which of the following is a suitable title for the passage?A. The Benefits of V.P.I.S. ActivitiesB. School-related Activities at V.P.I.S.C. Colleges Need Creative StudentsD. Activities Make You Creative11. Where is the passage probably from?A. A scientific magazine.B. A college application guideline.C. A club introduction.D. The website of V.P.I.S.DLife in the Internet age is lonely—or is it? That’s what experts in human interaction are debating after a new Stanford University survey has been published.According to the study, the more time people spend online, the less they can spare for real-life relationships with family and friends. The researchers asked 113 people about the Web’s influence on daily activities. 36%of those people are online for more than five hours a week.” As Internet use becomes more widespread, it will have an increasingly isolating (孤立的) effect on society,” says Robert Kraut, one of the researchers.Scholars and Web lovers criticized the study for stretching its data to make the “isolating” point. While 13%of regular Web users admitted the loss of time with loved ones, 60%reported watching less TV. The survey also shows that E-mail is the most popular online activity. If some of webheads (网虫)spend what was once passive TV time keeping company with friends via E-mails, “that’s a move toward greater connectedness,” says Paul Resnick, a professor at the University of Michigan.Thisisn’t the first claim that the Web should be criticized. A 1998 report monitored 73 Pittsburgh-area families’ Net use for a year. People who used the Internet more “talked less to family members and reported being lonelier and more depressed.” says Robert Kraut.“It’s true that there have been big declines in social connectedness over the past decades, but those declines began before the Internet was invented,” says Thomas Putnam.As Amitay Etzioni says, the Internet gives us a different kind of social life—not better or worse than before, but just different.12. Who claimed that the Web had negative influence?A. Paul Resnick.B. Robert Kraut.C. Thomas Putnam.D. Amitay Etzioni.13. The underlined word “This” in Para.4 refers to .A. the opinion expressed in Bowling AloneB. the survey made by the University of MichiganC. the conclusion in a report written in 1998D. the study conducted by Stanford University14. From the passage we learn that .A. watching TV used to take time away from staying onlineB. the Web was blamed more than once for causing an isolating effectC. 36%ofweb users spend more than five hours a week onlineD. the Web has the same influence as telephones and televisions15. The passage mainly discusses .A. how we can make a better use of the InternetB. how declines in social connectedness appearC. whether the Internet causes an isolating effectD. what a different life the Internet brings to us第二节(共5小题;每小题2分,满分10分)阅读下面短文,从短文后的选项中选出可以填入空白处的最佳选项。
江苏省常熟市2019-2020学年高二下学期期中考试数学含答案
2019-2020学年第二学期期中试卷高二数学2020.05注意事项答题前请认真阅读本注意事项及各题答题要求:1.本卷共4页,包含选择题(第1题~第12题)、填空题(第13题~第16题)、解答题(第17题~第22题),本卷满分150分,考试时间为120分钟,考试结束后,请将答题卷交回。
2.答题前,请您务必将自己的姓名、调研序列号用0.5毫米黑色墨水的签字笔填写在答题卷的规定位置。
3.请在答题卷上按照顺序在对应的答题区域内作答,在其它位置作答一律无效。
选择题必须使用2B铅笔填涂;非选择题必须使用0.5毫米黑色墨水的签字笔书写,字体工整、笔迹清楚。
4.请保持答题卷卷面清洁,不要折叠、破损.一律不准使用胶带纸、修正液、可擦洗的圆珠笔。
一、单项选择题:本大题共8小题,每小题5分,共40分。
在每小题给出的四个选项中,只有一项符合题目要求。
1.已知复数z=21ii(其中i是虛数单位),则复数z的虛部为A.-1B.-iC.1D.i2.火车开出车站一段时间内,速度v(单位:m/s)与行驶时间t(单位:s)之间的关系是v(t)=0.4t +0.6t2,则火车开出几秒时加速度为 2.8m/s2A.32s B.2s C.52s D.73s3.在正方体ABCD-A1B1C1D1中,平面A1BD与平面ABCD所成二面角的正弦值为A.33B.22C.63D.134.有6个人排成一排拍照,其中甲和乙相邻,丙和丁不相邻的不同的排法有A.240种B.144种C.72种D.24种5.若函数f(x)=x3-3bx+2在区间(2,3)内单调递增,则实数b的取值范围是A.b≤4B.b<4C.b≥4D.b>46.如图,在圆锥PO的轴截面PAB中,∠APB=60°,有一小球O1内切于圆锥(球面与圆锥的侧面、底面都相切),设小球O1的体积为V1,圆锥PO的体积为V,则V1:V的值为A.13B.49C.59D.237.若函数2xx f xax e存在两个不同零点,则实数a 的取值范围是A.(-∞,1e) B.(0,1e) C.(-∞,0)∪{1e} D.(-∞,0)∪(0,1e)8.从0,1,2,3,…,9中选出三个不同数字组成一个三位数,其中能被3整除的三位数个数为A.252B.216C.162D.228二、多项选择题:本大题共4小题,每小题5分,共20分,在每小题给出的四个选项中,有多项符合题目要求。
2019-2020学年江苏省苏州市常熟中学高三(上)抽测数学试卷(二)(解析版)
2019-2020学年江苏省苏州市常熟中学高三(上)抽测数学试卷(二)一、填空题1.设集合A={﹣2,1},集合B={1,2},则A∪B=.2.“x>1”是“x2≥1”的条件.3.直线x+y﹣1=0的倾斜角是.4.双曲线的渐近线方程是.5.抛物线上的点A的横坐标是,则A到其焦点F的距离为.6.已知,,则的值为.7.已知S n是等差数列{a n}的前n项和,若S3=4,S6=10,则S9=.8.如图,已知棱长为a的正方体ABCD﹣MNPQ的体积为V1,以B,D,M,P为顶点的三棱锥P﹣BDM的体积为V2,则=.9.若x,y满足约束条件.则的最大值为.10.已知椭圆的左焦点为F1(﹣c,0),右焦点为F2(c,0).若椭圆上存在一点P,线段PF2与圆相切于点E,且E为线段PF2中点,则该椭圆的离心率为.11.已知正实数x,y满足x+y=xy,则的最小值是.12.已知l1:mx﹣y﹣3m+1=0与l2:x+my﹣3m﹣1=0相交于点P,线段AB是圆C:(x+1)2+(y+1)2=4的一条动弦,且,则的最小值是13.已知函数,其中e为自然对数的底数,若存在实数x1,x2满足0≤x1<x2≤3,且f(x1)=f(x2),则x2﹣2x1的取值范围为.14.已知函数f(x)=ae x﹣lnx+lna,其中e为自然对数的底数,若对任意正实数x,都有f (x)≥0,则实数a的最小值为.二、解答题15.如图,在四棱锥P﹣ABCD中,底面ABCD为平行四边形,O为对角线BD的中点,E、F分别为棱PC,PD的中点,已知PA⊥平面ABCD.求证:(1)直线PB∥平面OEF;(2)平面OEF⊥平面ABCD.16.在三角形ABC中,角A,B,C所对的边分别为a,b,c,若sin A=,tan(A﹣B)=,角C为钝角,b=5.(1)求sin B的值;(2)求边c的长.17.已知圆C经过点A(﹣2,0),B(0,2),且圆心在直线y=x上,且,又直线l:y =kx+1与圆C相交于P、Q两点.(Ⅰ)求圆C的方程;(Ⅱ)若,求实数k的值;(Ⅲ)过点(0,1)作直线l1与l垂直,且直线l1与圆C交于M、N两点,求四边形PMQN 面积的最大值.18.已知圆O:x2+y2=r2(r>0)与椭圆C:相交于点M(0,1),N(0,﹣1),且椭圆的离心率为.(1)求r值和椭圆C的方程;(2)过点M的直线l另交圆O和椭圆C分别于A,B两点.①若,求直线l的方程;②设直线NA的斜率为k1,直线NB的斜率为k2,问:是否为定值,如果是,求出定值;如果不是,请说明理由.19.已知函数f(x)=x2﹣2ax﹣2alnx,g(x)=ln2x+2a2,其中x>0,a∈R.(Ⅰ)若x=1是函数f(x)的极值点,求a的值;(Ⅱ)若f(x)在区间(2,+∞)上单调递增,求a的取值范围;(Ⅲ)记F(x)=f(x)+g(x),求证:.20.已知数列{a n}与{b n}的前n项和分别为A n和B n,且对任意n∈N*,a n+1﹣a n=2(b n+1﹣b n)恒成立.(1)若,b1=2,求B n;(2)若对任意n∈N*,都有a n=B n及成立,求正实数b1的取值范围.2019-2020学年江苏省苏州市常熟中学高三(上)抽测数学试卷(二)参考答案与试题解析一、填空题1.设集合A={﹣2,1},集合B={1,2},则A∪B={﹣2,1,2}.【解答】解:∵A={﹣2,1},B={1,2},∴A∪B={﹣2,1,2}.故答案为:{﹣2,1,2}.2.“x>1”是“x2≥1”的充分不必要条件.【解答】解:由“x>1”可以推出“x2≥1”,所以具有充分性;由“x2≥1”可以推出“x<﹣1或x>1”,推导不出“x>1”,所以不具有必要性;故“x>1”是“x2≥1”的充分不必要条件.3.直线x+y﹣1=0的倾斜角是.【解答】解:因为直线的斜率为:﹣,所以tanα=﹣,所以直线的倾斜角为:.故答案为:.4.双曲线的渐近线方程是x±2y=0.【解答】解:由﹣=0,可得双曲线﹣=1的渐近线方程为x±2y=0.故答案为:x±2y=0.5.抛物线上的点A的横坐标是,则A到其焦点F的距离为.【解答】解:抛物线的准线方程为:x=﹣,抛物线上的点A的横坐标是,则A到其焦点F的距离为:+=2.故答案为:2.6.已知,,则的值为.【解答】解:∵,,∴=,∴sin()=sin(+)=cos()=,cos()=cos(+)=﹣sin()=﹣,则=2cos()sin()=2×=﹣故答案为:7.已知S n是等差数列{a n}的前n项和,若S3=4,S6=10,则S9=18.【解答】解:等差数列{a n}中,S3,S6﹣s3,s9﹣s6成等差数列,∴2(10﹣4)=4+s9﹣10则S9=18.故答案为:18.8.如图,已知棱长为a的正方体ABCD﹣MNPQ的体积为V1,以B,D,M,P为顶点的三棱锥P﹣BDM的体积为V2,则=.【解答】解:依题意得正方体的体积V1=a3,三棱锥A﹣BDM的体积V A﹣BDM=V M﹣ABD ==,又三棱锥P﹣BDM为正四面体,由对称性知V2=V1﹣4V A﹣BDM==,所以=.故答案为:.9.若x,y满足约束条件.则的最大值为3.【解答】解:作出不等式组对应的平面区域如图:(阴影部分ABC).设k=,则k的几何意义为区域内的点到原点的斜率,由图象知OA的斜率最大,由,解得,即A(1,3),k OA==3,即的最大值为3.故答案为:3.10.已知椭圆的左焦点为F1(﹣c,0),右焦点为F2(c,0).若椭圆上存在一点P,线段PF2与圆相切于点E,且E为线段PF2中点,则该椭圆的离心率为﹣1.【解答】解:如图所示,连接OE,F1P.∵线段PF2与圆相切于点E,∴OE⊥PF2.又O为F1F2的中点,∴OE==,OE∥PF1.∴PF1=c,PF2=2a﹣c,∠F1PF2=∠OEF2=90°.∴c2+(2a﹣c)2=(2c)2,化为:e2+2e﹣2=0,0<e<1,解得e=﹣1.故答案为:﹣1.11.已知正实数x,y满足x+y=xy,则的最小值是15.【解答】解:∵正实数x,y满足x+y=xy,∴x=>0,∴y>1,同理x>1,∴(x﹣1)(y﹣1)=1,则=+9=15,当且仅当且(x﹣1)(y﹣1)=1,即x=,y=4时取得等号,故答案为:15.12.已知l1:mx﹣y﹣3m+1=0与l2:x+my﹣3m﹣1=0相交于点P,线段AB是圆C:(x+1)2+(y+1)2=4的一条动弦,且,则的最小值是4﹣2【解答】解:设圆C的半径为r1∵l1:mx﹣y﹣3m+1=0与l2:x+my﹣3m﹣1=0,∴l1⊥l2,l1过定点(3,1),l2过定点(1,3),∴P轨迹为圆(x﹣2)2+(y﹣2)2=2,设圆心为M,半径为r2,作垂直线段CD⊥AB,CD=1,2||=|CM|﹣r1﹣r2=3﹣1﹣=4﹣2则,∴最小值为4﹣2故答案为:4﹣213.已知函数,其中e为自然对数的底数,若存在实数x1,x2满足0≤x1<x2≤3,且f(x1)=f(x2),则x2﹣2x1的取值范围为(﹣∞,1﹣ln2].【解答】解:记m=x2﹣2x1,①当0≤x1≤x2≤1 时,f(x1)=x1,f(x2)=x2,所以x1=x2,则m=﹣x2,故其最大值在x2=0时取得,为0,其最小值在x2=1时取得,为﹣1;②当1<x1≤x2≤3 时,f(x1)=e,f(x2)=e,所以e=e,即x1=x2,则m=﹣x2,故其最大值m max<m(1)=﹣1,其最小值m min≥m(3)=﹣3;③当0≤x1≤1<x2≤3 时,f(x1)=x1,f(x2)=e,所以x1=e,所以x2﹣2=lnx1,即x2=lnx1+2,故m=lnx1+2﹣2x1,设g(x)=lnx+2﹣2x,x∈[0,1],则g′(x)=﹣2,令g′(x)=0,得x=,当x∈(0,)时,g′(x)>0,g(x)单调递增,当x∈(,1)时,g′(x)<0,g(x)单调递减,所以当x→0时,g(x)的值无限趋于﹣∞;所以当x=时,g(x)取极大值也是最大值,即m max=g()=ln+2﹣1=1﹣ln2>﹣1,所以x2﹣2x1最大值为1﹣ln2.故答案为:(﹣∞,1﹣ln2].14.已知函数f(x)=ae x﹣lnx+lna,其中e为自然对数的底数,若对任意正实数x,都有f(x)≥0,则实数a的最小值为.【解答】解:若对任意正实数x都有f(x)≥0,则ae x﹣lnx+lna≥0,则ae x﹣lnx≥﹣lna恒成立,令g(x)=ae x﹣lnx,(x>0),g(x)最小值为﹣lna,=(x>0),当a≤0时,g′(x)<0,g(x)在(0,+∞)上单调递减,g(x)无最小值,符合题意,当a>0时,令h(x)=axe x﹣1,在(0,+∞)上是增函数,所以存在x0∈(0,+∞),使得ax0e0﹣1=0,(a=,lna=﹣lnx0﹣x0)①当x∈(0,x0)时,h(x)<0,g′(x)<0,g(x)单调递减,当x∈(x0,+∞)时,h(x)>0,g′(x)>0,g(x)单调递增,所以g(x)min=g(x0)=ae﹣lnx0,所以ae﹣lnx0=﹣lna,把①代入得﹣x0﹣2lnx0=0,化简得,令u(x)=(x>0),<0(x>0),所以u(x)在(0,+∞)上单调递减,又u(1)=0,所以x0=1,所以a=.故答案为:.二、解答题15.如图,在四棱锥P﹣ABCD中,底面ABCD为平行四边形,O为对角线BD的中点,E、F分别为棱PC,PD的中点,已知PA⊥平面ABCD.求证:(1)直线PB∥平面OEF;(2)平面OEF⊥平面ABCD.【解答】证明:(1)因为O为BD中点,F为PD中点,所以PB∥FO.因为PB⊄面OEF,FO⊂面OEF,所以PB∥平面OEF.(2)连接AC,因为四边形ABCD为平行四边形,所以AC与BD交于点O,O为AC中点,因为E为PC中点,所以AP∥OE,因为PA⊥平面ABCD,所以OE⊥平面ABCD,因为OE⊂平面OEF,所以平面OEF⊥平面ABCD.16.在三角形ABC中,角A,B,C所对的边分别为a,b,c,若sin A=,tan(A﹣B)=,角C为钝角,b=5.(1)求sin B的值;(2)求边c的长.【解答】解:(1)角C为钝角,由sin A=,则cos A==.那么:tan A=∵tan(A﹣B)=,即,可得:tan B=即,sin2B+cos2B=1,解得:sin B=.(2)由(1)可知:sin B=,则cos B==那么:sin C=sin(A+B)=sin A cos B+cos A sin B=正弦定理:=,可得:c=13.17.已知圆C经过点A(﹣2,0),B(0,2),且圆心在直线y=x上,且,又直线l:y =kx+1与圆C相交于P、Q两点.(Ⅰ)求圆C的方程;(Ⅱ)若,求实数k的值;(Ⅲ)过点(0,1)作直线l1与l垂直,且直线l1与圆C交于M、N两点,求四边形PMQN 面积的最大值.【解答】解:(I)设圆心C(a,a),半径为r.因为圆经过点A(﹣2,0),B(0,2),所以|AC|=|BC|=r,所以解得a=0,r=2,…所以圆C的方程是x2+y2=4.…(II)方法一:因为,…所以,∠POQ=120°,…所以圆心到直线l:kx﹣y+1=0的距离d=1,…又,所以k=0.…方法二:设P(x1,y1),Q(x2,y2),因为,代入消元得(1+k2)x2+2kx﹣3=0.…由题意得:…因为=x1•x2+y1•y2=﹣2,又,所以x1•x2+y1•y2=,…化简得:﹣5k2﹣3+3(k2+1)=0,所以k2=0,即k=0.…(III)方法一:设圆心O到直线l,l1的距离分别为d,d1,四边形PMQN的面积为S.因为直线l,l1都经过点(0,1),且l⊥l1,根据勾股定理,有,…又根据垂径定理和勾股定理得到,,…而,即…当且仅当d1=d时,等号成立,所以S的最大值为7.…方法二:设四边形PMQN的面积为S.当直线l的斜率k=0时,则l1的斜率不存在,此时.…当直线l的斜率k≠0时,设则,代入消元得(1+k2)x2+2kx﹣3=0所以同理得到.…=…因为,所以,…当且仅当k=±1时,等号成立,所以S的最大值为7.…18.已知圆O:x2+y2=r2(r>0)与椭圆C:相交于点M(0,1),N(0,﹣1),且椭圆的离心率为.(1)求r值和椭圆C的方程;(2)过点M的直线l另交圆O和椭圆C分别于A,B两点.①若,求直线l的方程;②设直线NA的斜率为k1,直线NB的斜率为k2,问:是否为定值,如果是,求出定值;如果不是,请说明理由.【解答】解:(1)∵圆O:x2+y2=r2(r>0)与椭圆C:相交于点M(0,1),∴b=r=1,又离心率为e=,且a2=b2+c2,∴a=.∴椭圆方程为;(2)①∵过点M的直线l另交圆O和椭圆C分别于A,B两点,∴设直线l的方程为y=kx+1(k≠0),由,得(2k2+1)x2+4kx=0,∴B(,),同理由,得到(k2+1)x2+2kx=0,∴A(,),∵,∴,得k=,即直线l的方程为.②由①知,B(,),A(,),,=,∴为定值.19.已知函数f(x)=x2﹣2ax﹣2alnx,g(x)=ln2x+2a2,其中x>0,a∈R.(Ⅰ)若x=1是函数f(x)的极值点,求a的值;(Ⅱ)若f(x)在区间(2,+∞)上单调递增,求a的取值范围;(Ⅲ)记F(x)=f(x)+g(x),求证:.【解答】解:(Ⅰ);∵x=1是函数f(x)的极值点;∴f′(1)=2﹣2a﹣2a=0,解得;经检验x=1为函数f(x)的极值点,所以.(II)∵f(x)在区间(2,+∞)上单调递增;∴在区间(2,+∞)上恒成立;∴对区间(2,+∞)恒成立;令,则;当x∈(2,+∞)时,M′(x)>0,有;∴a的取值范围为.(Ⅲ)F(x)=x2﹣2ax﹣2alnx+ln2x+2a2=;令;则=;令Q(x)=x﹣lnx,则;显然Q(x)在(0,1]上单调递减,在(1,+∞)上单调递增;则Q(x)min=Q(1)=1,则;故.20.已知数列{a n}与{b n}的前n项和分别为A n和B n,且对任意n∈N*,a n+1﹣a n=2(b n+1﹣b n)恒成立.(1)若,b1=2,求B n;(2)若对任意n∈N*,都有a n=B n及成立,求正实数b1的取值范围.【解答】解:(1)A n=n2,∴n≥2时,a n=A n﹣A n﹣1=n2﹣(n﹣1)2=2n﹣1.n=1时,a1=1.n=1时适合上式.∴a n=2n﹣1.∵a n+1﹣a n=2(b n+1﹣b n),∴b n+1﹣b n=2=1,又b1=2.∴数列{b n}是等差数列,首项为2,公差为1.∴B n=2n+×1=.(2)对任意n∈N*,都有a n=B n,∴a n+1﹣a n=B n+1﹣B n=b n+1.∴b n+1﹣b n=(a n+1﹣a n)=b n+1.∴b n+1=2b n,b1>0.∴数列{b n}是等比数列,公比为2.∴B n=b1=(2n﹣1)b1.另一方面:==﹣.∵成立,∴﹣+﹣+……+﹣=﹣=(1﹣),∴b1>3(1﹣)∵对任意n∈N*,都成立,∴b1≥3.∴正实数b1的取值范围是[3,+∞).。
江苏省苏州市常熟中学2019_2020学年高二物理下学期6月质量检测试题含解析
故C正确;
D.原子发出光子后,向低能级跃迁,库仑力做正功,其核外电子动能变大,电势能变小,故D正确。
应当选ACD。
10. 如图是水面上两列频率一样的波在某时刻的叠加情况,以波源S1、S2为圆心的两组同心圆弧分别表示同一时刻两列波的波峰〔实线〕和波谷〔虚线〕,s1的振幅A1=4cm,S2的振幅A2=3cm,如此如下说法正确的答案是〔 〕
D.因为
所以光在水滴中的波长
即a光、b光在水滴中传播的波长都比各自在真空中传播的波长要短,故D错误;
E.根据临界角公式
知,折射率较大的光临界角较小,容易发生全反射,如此知b光的临界角比a光的大,假如b光能够发生全反射,如此a光也一定能够发生全反射,故E正确。
11. 如如下图,静止的 核发生 衰变后生成反冲 核,两个产物都在垂直于它们的速度方向的匀强磁场中做匀速圆周运动,如下说法正确的答案是〔 〕
A. 衰变方程可表示为
B. 核和 粒子 圆周轨道半径之比为1:45
C. 核和 粒子的动能之比为1:45
D. 核和 粒子在匀强磁场中旋转的方向相反
【答案】AB
【解析】
A. 水滴对a光的折射率大于对b光的折射率
B.a光在水滴中的传播速度大于对b光在水滴中的传播速度
C. 用同一台双缝干预仪做光的双缝干预实验,a光相邻的亮条纹间距小于b光的相邻亮条纹间距
D.a、b光在水滴中传播的波长都比各自在真空中传播的波长要长
E. 假如a、b光在同一介质中,以一样的入射角由介质射向空气,假如b光能够发生全反射,如此a光也一定能够发生全反射
【解析】
【详解】A.根据 知,这群氢原子能辐射出三种不同频率的光子,从n=3向n=2跃迁的光子频率最小,波长最长,故A正确;
2019-2020学年江苏省苏州市常熟中学高二上学期12月月考数学试题(解析版)
2019-2020学年江苏省苏州市常熟中学高二上学期12月月考数学试题一、单选题1.不等式2230x x +->的解集是( ) A .{|31}x x -<<B .{|13}x x -<<C .3|}1{x x ≤<D .3|32x x ⎧⎫-≤<⎨⎬⎩⎭【答案】B【解析】利用一元二次不等式的解法求解出2230x x +->,然后写成集合形式. 【详解】解:2230x x +-> 等价于2230x x --<, 即(3)(1)0x x -+<, 解得:13x -<<,不等式2230x x +->的解集为{|13}x x -<<. 故选:B. 【点睛】本题考查了一元二次不等式的解法,一般情况下首先要将二次项前的系数变为正数,最后的结果要以集合的形式呈现.2.椭圆2219x y m +=的焦距是2,那么实数m 的值为( )A .5B .5或13C .8或10D .10【答案】C【解析】计算得到1c =,讨论9m >和09m <<两种情况,计算得到答案. 【详解】椭圆2219x y m +=的焦距是2,故22c =,1c =.当9m >时,91m -=,解得10m =;当09m <<时,91m -=,解得8m =.【点睛】本题考查了根据椭圆的焦距求参数,漏解是容易发生的错误. 3.若正数x ,y 满足131y x+=,则34x y +的最小值是( ) A .24 B .28C .25D .26【答案】C【解析】利用“乘1法”与基本不等式的性质即可得出. 【详解】解:Q 正数x ,y 满足131y x+=,则1331234(34)()1313325x y x y x y y x y x +=++=+++⨯…,当且仅当25x y ==时取等号.34x y ∴+的最小值是25.故选:C . 【点睛】本题考查了“乘1法”与基本不等式的性质,考查了推理能力与计算能力,属于基础题. 4.抛物线24y x =上的点()04,M y 到其焦点F 的距离为( ) A .3 B .4C .5D .6【答案】C【解析】利用焦半径公式可得FM 的长度. 【详解】44152pFM =+=+=,故选C. 【点睛】如果抛物线的方程为()220y px p =>,则抛物线上的点()00,M x y 到焦点F 的距离为02px +. 5.设n S 是等比数列{}n a 的前n 项的和,若6312a a =-,则63S S =( )A .23B .12 C .14D .13【解析】根据6312a a =-得到312q =-,代入公式计算得到答案. 【详解】36312a q a ==-,61363311111121q a S q q q S a q--==+=--. 故选:B . 【点睛】本题考查了等比数列的公式的应用,意在考查学生的计算能力.6.已知平面α,β的法向量分别为()2,3,a λ=r 和()4,,2b μ=-r(其中,R λμ∈),若//αβ,则λμ+的值为( )A .52-B .-5C .52D .5【答案】D【解析】根据平面平行得到//a b r r,故()()2,3,4,,2k λμ=-,计算得到答案. 【详解】//αβ,则//a b r r ,故()()2,3,4,,2k λμ=-,即2432kk kμλ=⎧⎪=⎨⎪=-⎩,解得61μλ=⎧⎨=-⎩.故5λμ+=. 故选:D . 【点睛】本题考查了法向量的平行问题,意在考查学生的计算能力.7.某同学在画“切面圆柱体”(用与圆柱底面不平行的平面去截圆柱,底面与截面之间的部分叫做切面圆柱体)的过程中,发现“切面”是一个椭圆,若“切面”所在平面与底面成60︒角,则该椭圆的离心率为( ) A .12B.2C.2D .13【答案】C【解析】如图所示,切面与底面的二面角的平面角为BAM ∠,设圆半径为r ,则2AM r =,4AB r =,2CD r =,得到2a r =,b r =,3c r =,得到答案.【详解】如图所示:切面与底面的二面角的平面角为BAM ∠,设圆半径为r , 则2AM r =,4AB r =,2CD r =.故24a r =,22b r =,故2a r =,b r =,3c r =,32e =. 故选:C .【点睛】本题考查了圆柱的切面,椭圆离心率,意在考查学生的综合应用能力.8.椭圆221169x y +=中以点M(1,2)为中点的弦所在直线斜率为( )A .932-B .9 32C .9 64D .9 16【答案】A【解析】先设出弦的两端点的坐标,分别代入椭圆方程,两式相减后整理即可求得弦所在的直线的斜率. 【详解】设弦的两端点为()11,A x y ,()22,B x y ,代入椭圆得2211222211691169x y x y ⎧+=⎪⎪⎨⎪+=⎪⎩, 两式相减得()()()()121212120169x x x x y y y y +-+-+=,即()()()()12121212 169x x x x y y y y +-+-=-,即()()()()12121212916x x y y y y x x +--=+-,即121292164y y x x -⨯-=⨯-,即12129 32y y x x -=--,∴弦所在的直线的斜率为932-,故选A.【点睛】本题主要考查了椭圆的性质以及直线与椭圆的关系.在解决弦长的中点问题,涉及到“中点与斜率”时常用“点差法”设而不求,将弦所在直线的斜率、弦的中点坐标联系起来,相互转化,达到解决问题的目的,属于中档题.9.已知双曲线22221x y a b-=的左右焦点为12,F F ,右支上一点B 与1F 的连线交双曲线左支于点A ,若224,3,5AB BF AF ===,则12F AF ∆的面积为() A .2 B .3C .4D .5【答案】B【解析】根据双曲线的定义列方程,求得1AF ,然后求得12F AF ∆的面积. 【详解】 由于22222AB BF AF +=,所以三角形2ABF 是直角三角形,且22ABF π∠=.根据双曲线的定义可知21122AF AF BF BF a -=-=,即11543AF AF -=+-,解得12AF =.所以12F AF ∆的面积为121123322AF BF ⨯⨯=⨯⨯=.故选B.【点睛】本小题主要考查双曲线的定义,考查三角形面积的计算,考查勾股定理,考查数形结合的思想方法,属于基础题.10.对于以1F ,2F 为公共焦点的椭圆E 和双曲线C ,设P 是它们的一个公共点,1e ,2e 分别为它们的离心率.若1260F PF ∠=︒,则1211e e +的最大值为( ) A .34B .43C .334D 43【答案】D【解析】设椭圆方程是222211x y a b +=1,双曲线方程是222222x y a b -=1,由定义可得|PF 1|+|PF 2|=2a 1,|PF 1|﹣|PF 2|=2a 2,求出|PF 1|=a 1+a 2,|PF 2|=a 1﹣a 2,利用余弦定理,化简4221213e e =+的表达式,利用柯西不等式求解即可. 【详解】设椭圆方程是222211x y a b +=1,双曲线方程是222222x y a b -=1,由定义可得|PF 1|+|PF 2|=2a 1,|PF 1|﹣|PF 2|=2a 2, ∴|PF 1|=a 1+a 2,|PF 2|=a 1﹣a 2, 在△F 1PF 2中由余弦定理可得,(2c )2=(a 1+a 2)2+(a 1﹣a 2)2+2(a 1+a 2)(a 1﹣a 2)cos60°, 即4c 2=a 12+3a 22, ∴4221213e e =+, 由柯西不等式得(113+)(221213e e +)≥(1121e e ⨯)2=(1211e e +)2, 即(1211e e +)243≤⨯4163=,即1211e e +≤,当且仅当e1=e2= 故选:D . 【点睛】本题考查椭圆以及双曲线的简单性质的应用,涉及余弦定理以及柯西不等式的应用,考查转化思想以及计算能力.二、多选题11.等差数列{}n a 中,若67S S <且78S S >,则下面结论正确的是( ) A .10a > B .96S S <C .7a 最大D .()7max n S S =【答案】ABD【解析】根据题意得到70a >,80a <,0d <,依次判断每个选项得到答案. 【详解】等差数列{}n a 中,若67S S <且78S S >,则70a >,80a <,故0d <.1760a a d =->,A 正确;96789830S S a a a a -=++=<,故96S S <,B 正确; 67a a >,故C 错误;70a >,80a <,故()7max n S S =,D 正确;故选:ABD . 【点睛】本题考查了等差数列的性质,意在考查学生对于数列公式方法的灵活运用.12.已知抛物线C :()220y px p =>的焦点为F ,直线的斜率为3且经过点F ,直线l 与抛物线C 交于点A ,B 两点(点A 在第一象限)、与抛物线的准线交于点D ,若4AF =,则以下结论正确的是( ) A .2p = B .F 为AD 中点C .2BD BF =D .2BF =【答案】ABC【解析】如图所示:作AC ⊥准线于C ,AM x ⊥轴于M ,BE ⊥准线于E ,计算得到2p =,F 为AD 中点,2DB BF =,43BF =,得到答案. 【详解】如图所示:作AC ⊥准线于C ,AM x ⊥轴于M ,BE ⊥准线于E . 直线的斜率为3,故tan 3AFM ∠=,3AFM π∠=,4AF =,故2MF =,3AM =.2,232p A ⎛⎫+ ⎪⎝⎭,代入抛物线得到2p =; 2NF FM ==,故AMF DNF ∆≅∆,故F 为AD 中点;6BDE π∠=,故22DB BE BF ==;2BD BF =,4BD BF DF AF +===,故43BF =; 故选:ABC .【点睛】本题考查了抛物线相关命题的判断,意在考查学生的综合应用能力.13.如图,已知椭圆1C :2214x y +=,过抛物线2C :24x y =焦点F 的直线交抛物线于M ,N 两点,连接NO ,MO 并延长分别交1C 于A ,B 两点,连接AB ,OMN ∆与OAB ∆的面积分别记为OMN S ∆,OAB S ∆,则在下列命题中,正确的为( )A .若记直线NO ,MO 的斜率分别为1k ,2k ,则12k k 的大小是定值为14- B .OAB ∆的面积OAB S ∆是定值1C .线段OA ,OB 长度的平方和22OA OB +是定值5 D .设OMNOABS S λ∆∆=,则2λ≥ 【答案】ABCD【解析】()0,1F ,设直线方程为1y kx =+,()()1122,,A x y B x y ,联立方程得到121244x x kx x +=⎧⎨=-⎩,再计算每个选项的值,得到答案. 【详解】()0,1F ,设直线方程为1y kx =+,()()1122,,A x y B x y ,不妨设N 在第一象限. 则241x y y kx ⎧=⎨=+⎩,故2440x kx --=.216160k ∆=+>恒成立,121244x x k x x +=⎧⎨=-⎩,()()()21212122212121212121111144kx kx k x x k x x y y k k k k x x x x x x +++++=⋅===--=-⋅⋅.ON :1y k x =,则12214y k x x y =⎧⎪⎨+=⎪⎩,解得122114141A k k ⎛⎫++, 同理222224141B k k ⎛⎫++,即122114141B k k ⎛⎫++.点A 到直线OB的距离d ==11122OABS d OB ∆=⋅⋅==. 2222112222111141641541414141k k OA OB k k k k +==+++=++++.12112OMN S x x ∆=⨯⨯-,故()222212121211444444OMN S x x x x x x k ∆⎡⎤=-=+-=+≥⎣⎦.故2OMN S ∆≥,2OMNOABS S λ∆∆=≥. 故选:ABCD . 【点睛】本题考查了椭圆和抛物线的综合问题,涉及斜率,面积,定值,意在考查学生的计算能力和综合应用能力.三、填空题14.命题“x R ∀∈,20x ≤”的否定是______. 【答案】x R ∃∈,20x >【解析】直接根据全称命题的否定是特称命题得到答案. 【详解】全称命题的否定是特称命题,故命题“x R ∀∈,20x ≤”的否定是“x R ∃∈,20x >”. 故答案为:x R ∃∈,20x >. 【点睛】本题考查了全称命题的否定,意在考查学生的推断能力.15.已知{}n a 是公差为2-的等差数列,n S 为其前n 项和,若21a +,51a +,71a +成等比数列,则1a =_____,当n =_______时,n S 取得最大值. 【答案】19. 10.【解析】根据题意,列出方程,即可求出首项,再由等差数列的求和公式,即可得出结果. 【详解】因为21a +,51a +,71a +成等比数列, 所以()75221(1)(1)+=++a a a , 又{}n a 是公差为2-的等差数列,所以()2111821(1)(112)+=---++a a a , 即()2111()7(111)--=-a a a ,解得119a =,所以2219(1)20(10)100=--=-+=--+n n n n n S n n ,因此,当10n =时,n S 取得最大值. 故答案为(1). 19. (2). 10. 【点睛】本题主要考查等差数列与等比数列,熟记数列的求和公式与通项公式即可,属于常考题型.16.已知椭圆()222210x y a b a b+=>>的左,右焦点分别为1F ,2F ,过点1F 作直线交椭圆于P ,Q 两点,且212PF F F =,1134PF QF =,则椭圆的离心率为______. 【答案】57【解析】根据1212cos cos PF F PF F ∠=-∠,利用余弦定理得到2251270a ac c -+=,计算得到答案. 【详解】2122PF F F c ==,故122PF a c =-,1134PF QF =,故()132QF a c =-,2113222QF a QF a c =-=+. ()121212cos cos cos PF F PF F PF F π∠=-∠=-∠,利用余弦定理得到:()()()()22222291344444223222222a c c a c a c c c a c c a c c ⎛⎫-+-+ ⎪-+-⎝⎭=-⋅-⋅⋅-⋅, 整理化简得到:2251270a ac c -+=,即271250e e -+=,解得57e =或1e =(舍去).故答案为:57. 【点睛】本题考查了椭圆的离心率,意在考查学生的计算能力和综合应用能力.17.已知,a b R +∈,且()27a b b ++=,则32ab a b ++的最小值为_______________. 【答案】10【解析】由()27a b b ++=解出72ba b -=+,将其代入32ab a b ++后,变形为9(2)42b b ++++,再利用基本不等式可求得最小值. 【详解】因为()27a b b ++=,所以72ba b -=+, 所以732(3)2(3)22bab a b a b b b b b -++=++=+++ [9(2)](21)2(2)42b b b b -+++=++-+9(1)(21)2(2)42b b b =-++++-+ 99(2)12(2)42b b b =-++-++-+9(2)42b b =++++,因为,a b R +∈,所以9(2)42b b ++++4≥6410=+=, 当且仅当922b b =++,解得1b =,此时71212a -==+, 所以32ab a b ++的最小值为:10. 故答案为10 【点睛】本题考查了利用基本不等式求和的最小值,解题关键是要变形为积为定值的形式,属于中档题.四、解答题18.已知双曲线C 的中心在原点,焦点1F 、2F 在坐标轴上,一条渐近线方程为y x =.且过点()N . (1)求双曲线C 的方程;(2)若点N 在此双曲线上,且1260F NF ∠=︒,求12F NF ∆的面积.【答案】(1)22144x y -= (2)【解析】(1)设双曲线方程:()220x y λλ-=≠,代入点()N ,计算得到答案.(2)利用余弦定理计算得到16mn =,得到面积. 【详解】(1)∵渐近线方程:y x =,∴设双曲线方程:()220x y λλ-=≠,将()N 代入方程有4λ=,∴双曲线C 方程:22144x y -=.(2)设1F N m =,2F N n =,∴2242cos6032m n m n mn ⎧-=⎨+-⋅︒=⎩,∴16mn =.∴1sin 602S mn ∆=︒=. 【点睛】本题考查了双曲线方程,面积的计算,意在考查学生的计算能力. 19.已知函数()2f x ax x a =+-,a R ∈.(1)若函数()f x 有最大值178,求实数a 的值; (2)解关于x 不等式()1f x >. 【答案】(1)2-或18-;(2)见解析【解析】(1)根据题意有20411748a a a<⎧⎪⎨--=⎪⎩,解得答案.(2)化简得到()()110x ax a -++>,讨论0a =,0a >,0a <三种情况得到答案. 【详解】(1)由题意得20411748a a a<⎧⎪⎨--=⎪⎩,∴2a =-或18a =-.(2)()1f x >,即210ax x a +-->,即()()110x ax a -++>,0a =时,10x ->,解集为()1,+∞.0a >时,()110a x x a +⎛⎫-+> ⎪⎝⎭,解集为()1,1,a a +⎛⎫-∞-+∞ ⎪⎝⎭U .0a <时,()110a x x a +⎛⎫-+< ⎪⎝⎭,102a -<<时,解集为11,a a +⎛⎫- ⎪⎝⎭;12a =-时,解集为∅;12a <-时,解集为1,1a a +⎛⎫-⎪⎝⎭. 综上所述:0a =时,解集为()1,+∞;0a >时,解集为()1,1,a a +⎛⎫-∞-+∞ ⎪⎝⎭U ;102a -<<时,解集为11,a a +⎛⎫- ⎪⎝⎭;12a =-时,解集为∅;12a <-时,解集为1,1a a +⎛⎫-⎪⎝⎭. 【点睛】本题考查了根据二次函数最值求参数,解不等式,分类讨论是常用的数学方法,需要熟练掌握.20.已知等差数列{}n a 满足32a =,前3项和392S =. (1)求{}n a 的通项公式;(2)设等比数列{}n b 满足11b a =,415b a =,求数列{}n n a b 的前n 项和n T . 【答案】(1)12n n a +=(2)12n n T n -=⋅ 【解析】(1)根据等差数列公式计算得到答案. (2)计算()212n n n a b n -=+⋅,利用错位相减法计算得到答案.【详解】(1)设等差数列{}n a 的公差为d ,则1122329322a d a d +=⎧⎪⎨⨯+=⎪⎩,∴1112a d =⎧⎪⎨=⎪⎩,∴12n n a +=. (2)11b =,48b =,设等比数列{}n b 的公比为q ,∴2q =,∴12n n b -=,∴()212n n n a b n -=+⋅,∴()12223212n n T n --=⨯+⨯+⋅⋅⋅++⋅,()021222212n n n T n n --=⨯+⋅⋅⋅+⋅++⋅,∴()0121122212n n n T n ---=+++⋅⋅⋅+-+⋅()111211212n n n ---=+-+⋅-12n n -=-⋅.∴12n n T n -=⋅.【点睛】本题考查了等差数列通项公式,错位相减法,意在考查学生对于数列公式方法的灵活运用.21.已知抛物线C :y 2=3x 的焦点为F ,斜率为32的直线l 与C 的交点为A ,B ,与x 轴的交点为P .(1)若|AF |+|BF |=4,求l 的方程; (2)若3AP PB =u u u v u u u v,求|AB |. 【答案】(1)12870x y --=;(2)3. 【解析】(1)设直线l :3y =x m 2+,()11,A x y ,()22,B x y ;根据抛物线焦半径公式可得1252x x +=;联立直线方程与抛物线方程,利用韦达定理可构造关于m 的方程,解方程求得结果;(2)设直线l :23x y t =+;联立直线方程与抛物线方程,得到韦达定理的形式;利用3AP PB =u u u r u u u r可得123y y =-,结合韦达定理可求得12y y ;根据弦长公式可求得结果. 【详解】(1)设直线l 方程为:3y =x m 2+,()11,A x y ,()22,B x y 由抛物线焦半径公式可知:12342AF BF x x +=++= 1252x x ∴+=联立2323y x m y x ⎧=+⎪⎨⎪=⎩得:()229121240x m x m +-+= 则()2212121440m m ∆=--> 12m ∴<121212592m x x -∴+=-=,解得:78m =-∴直线l 的方程为:3728y x =-,即:12870x y --= (2)设(),0P t ,则可设直线l 方程为:23x y t =+联立2233x y t y x⎧=+⎪⎨⎪=⎩得:2230y y t --= 则4120t ∆=+> 13t ∴>-122y y ∴+=,123y y t =-3AP PB =u u u r u u u rQ 123y y ∴=- 21y ∴=-,13y = 123y y ∴=-则()2121241341314412933AB y y y y =+⋅+-=⋅+=【点睛】本题考查抛物线的几何性质、直线与抛物线的综合应用问题,涉及到平面向量、弦长公式的应用.关键是能够通过直线与抛物线方程的联立,通过韦达定理构造等量关系. 22.(本小题满分10分)如图,已知四棱锥的底面是菱形,对角线交于点,,,,底面,设点满足.(1)当时,求直线与平面所成角的正弦值;(2)若二面角的大小为,求的值.【答案】(1);(2).【解析】试题分析:(1)以为坐标原点,建立坐标系,求出相关点的坐标,平面的法向量,利用空间数量积求解直线与平面所成角的正弦值;(2)求出平面的一个法向量,设,代入,求得,求出平面的法向量,通过向量的数量积得到方程即可求出的值.试题解析:(1)以为坐标原点,建立坐标系,则,,,,,所以,,.当时,得,所以,设平面的法向量,则,得,令,则,所以平面的一个法向量,所以,即直线与平面所成角的正弦值.(2)易知平面的一个法向量.设,代入,得,解得,即,所以,设平面的法向量,则,消去,得,令,则,,所以平面的一个法向量,所以,解得或,因为,所以.【考点】1.二面角的平面角的求法;2.直线与平面所成的角;3.利用空间向量求空间角.23.如图,C、D是离心率为的椭圆的左、右顶点,、是该椭圆的左、右焦点,A、B是直线4上两个动点,连接AD和BD,它们分别与椭圆交于点E、F两点,且线段EF恰好过椭圆的左焦点. 当时,点E恰为线段AD的中点.(Ⅰ)求椭圆的方程;(Ⅱ)求证:以AB为直径的圆始终与直线EF相切.【答案】(Ⅰ)(Ⅱ)见证明【解析】(Ⅰ)由题意可得,结合可求出,进而可求得椭圆的方程;(Ⅱ)设EF的方程为:,E()、F(),与椭圆联立,运用韦达定理得,,又设,由三点共线得,,求出中点坐标,求出点M到直线EF的距离,进而证得结果.【详解】(Ⅰ)∵当时,点E恰为线段AD的中点,∴,又,联立解得:,,,∴椭圆的方程为.(Ⅱ)设EF的方程为:,E()、F(),联立得:∴,∴……()又设,由A、E、D三点共线得,同理可得.,∴.设AB中点为M,则M坐标为()即(),∴点M到直线EF的距离.故以AB为直径的圆始终与直线EF相切.【点睛】本题主要考查了椭圆方程的求法,直线与椭圆的位置关系,韦达定理的运用,考查了学生的计算能力,计算量较大,“设而不求,整体代换”的思想,直线与圆相切即圆心到直线的距离等于圆的半径,有一定难度.。
江苏省常熟中学2019-2020学年高二六月质量检测数学试题
省熟中2019~2020学年度第二学期高二年级6月份质量检测数学试题一、单项选择题1.已知i 为虚数单位,设复数121iz i i-=++,则z =( )A .0B .12C .1D2.已知二面角l αβ--的大小为60︒,,m n 为异面直线,且m α⊥,n β⊥,则,m n 所成的角为( ) A .30︒B .60︒C .90︒D .120︒3.下列函数中,在其定义域内既是奇函数又是减函数的是( ) A .3y x =-B .sin y x =C .()10y x x=≠D .12xy ⎛⎫= ⎪⎝⎭4.为了研究某班学生的脚长x (cm)和身高y (cm)的关系,从该班随机抽取10名学生,根据测量数据的散点图可以看出y 与x 之间有线性相关关系,设其回归直线方程为y bx a =+.已知101225ii x==∑,1011600ii y==∑,4b =.该班某学生的脚长为24,据此估计其身高为( )A .160B .163C .166D .1705.若多项式()()()10210019101...11x x a a x a x a x +=+++++++,则9a =( )A .9B .10C .-9D .-106.已知球O 半径为1,,,A B C 三点都在球面上,,A B 两点和,A C 两点的球面距离都是4π,,B C 两点的球面距离是3π,则二面角B OA C --的大小为( ) A .4π B .3π C .2πD .23π7.有12名同学合影,站成了前排4人后排8人,现摄影师要从后排8人中抽2人调整到前排,若其他人的相对顺序不变,则不同调整方法的种数是( ) A .2283C AB .2686C AC .2286C AD .2285C A8.已知e 为自然对数的底数,设函数()()()()111,2kxf x e x k =--=,则( )A .当1k =时,()f x 在1x =处取得极小值B .当1k =时,()f x 在1x =处取得极大值C .当2k =时,()f x 在1x =处取得极小值D .当2k =时,()f x 在1x =处取得极大值 二、多项选择题9.设某高中的男生体重y (kg)与身高x (cm)具有线性相关关系,根据一组样本数据(),i i x y ()1,2,...,i n =,用最小二乘法建立的回归方程为0.8580.71y x =-,则下列结论中正确的是( ) A .y 与x 有正的线性相关关系 B .回归直线过样本点的中心(),x yC .若该高中某男生身高增加1cm ,则其体重约增加0.85kgD .若该高中某男生身高为170cm ,则可断定其体重必为63.79kg10.已知在n的展开式中,前3项的系数成等差数列,则下列结论正确的是( ) A .展开式中所有项的系数之和为256 B .展开式中含x 的一次项为5358T x = C .展开式中有3项有理项D .展开式中系数最大项为第3项和第4项11.若长方体1111ABCD A B C D -的底面是边长为2的正方形,高为4,E 是1DD 的中点,则( )A .11B E A B ⊥B .平面1B CE平面1A BDC .三棱锥11C B CE -的体积为83D .三棱锥111C B CD -的外接球的表面积为24π12.现有4个小球和4个小盒子,下面的结论正确的是( ) A .若4个不同的小球放入编号为1,2,3,4盒子,则共有24种放法B .若4个相同的小球放入编号为1,2,3,4盒子,且恰有二个空盒的放法共有18种C .若4个不同的小球放入编号为1,2.3,4盒子,且恰有一个空盒的放法共有144种D .若编号为1,2,3,4的小球放入编号为1,2,3,.4盒子,没有一个空盒但小球的编号和盒子的编号全不相同的放法共有9种 三、填空题 13.函数()f x =的定义域为______.14.已知随机事件,A B ,且()12P A =,()13P B =,()12P B A =,则()P A B =______. 15.如图,在三棱锥D AEF -中,1A ,1B ,1C 分别是DA ,DE ,DF 的中点,,B C 分别是,AE AF 的中点,设三棱柱111ABC A B C -的体积为1V ,三棱锥D AEF -的体积为2V ,则12:V V =______.16.设函数()33,2,x x x af x x x a ⎧-≤=⎨->⎩.①若0a =,则()f x 的最大值为______;②若()f x 无最大值,则实数a 的取值范围为______. 四、解答题17.假定某射手每次射击命中目标的概率为23.现有3发子弹,该射手一旦射中目标,就停止射击,否则就一直独立地射击到子弹用完.设耗用子弹数为X . (1)求X 的概率分布;(2)分别求均值()E X 和方差()V X .18.已知函数()1212xxf x +=-,()21log 1x g x x+=-,()()()h x f x g x =+. (1)判别函数()h x 的奇偶性,并证明; (2)解不等式()2g x ≤;(3)若不等式()0f x m ->对任意[]1,2x ∈恒成立,求实数m 的取值范围. 19.已知函数()()()3211cos sin 32f x x ax x a x x a R =-+--∈. (1)求证:当0x >时,sin x x >;(2)当0a ≥时,讨论函数()f x 的单调性,并判断有无极值,有极值时求出极值.20.山东省2020年高考将实施新的高考改革方案.考生的高考总成绩将由3门统-高考科目成绩和自主选择的3门普通高中学业水平等级考试科目成绩组成,总分为750分.其中,统一高考科目为语文、数学、外语,自主选择的3门普通高中学业水平等级考试科目是从物理、化学、生物、历史、政治、地理6科中选择3门作为选考科目,语、数、外三科各占150分,选考科目成绩采用“赋分制”,即原始分数不直接用,而是按照学生分数在本科目考试的排名来划分等级并以此打分得到最后得分.根据高考综合改革方案,将每门等级考试科目中考生的原始成绩从高到低分为A 、B +、B 、C +、C 、D +、D 、E 共8个等级.参照正态分布原则,确定各等级人数所占比例分别为3%、7%、16%、24%、24%、16%、7%、3%.等级考试科目成绩计入考生总成绩时,将A 至E 等级内的考生原始成绩,依照等比例转换法则,分别转换到91~100、 81~90、71~80,61~70、51~60、41~50、31~40、21~30八个分数区间,得到考生的等级成绩.举例说明:某同学化学学科原始分为65分,该学科C +等级的原始分分布区间为58~69,则该同学化学学科的原始成绩属C +等級.而C +等级的转换分区间为61~70,那么该同学化学学科的转换分为:设该同学化学科的转换等级分为x ,696570655861xx --=--,求得66.73x ≈.四舍五入后该同学化学学科赋分成绩为67. (1)某校高一年级共2000人,为给高一学生合理选科提供依据,对六个选考科目进行测试,其中物理考试原始成绩基本服从正态分布()2~60,12N ξ.①若小明同学在这次考试中物理原始分为84分,等级为B +,其所在原始分分布区间为82~93,求小明转换后的物理成绩;②求物理原始分在区间(72,84)的人数;(2)按高考改革方案,若从全省考生中随机抽取4人,记X 表示这4人中等级成绩在区间[61,80]的人数,求X 的分布列和数学期望. (附:若随机变量()2~,Nξμσ,则()0.683P μσξμσ-<<+=,()220.954P μσξμσ-<<+=,()330.997P μσξμσ-<<+=21.如图,长方体1111ABCD A B C D -中,,E P 分别是BC ,11A D 的中点,,M N 分别是AE ,1CD 的中点,1AD AA a ==,2AB a =.(1)求证:MN平面11ADD A ;(2)求二面角P AE D --的正弦值; (3)求三棱锥P DEN -的体积.22.已知函数()()()1xf x ax ea R =-∈.(1)求函数()f x 的单调区间;(2)是否存在正实数a ,使得()1f x ≤对任意x R ∈恒成立?若存在,求出a 的值;若不存在,请说明理由.。
江苏省苏州市常熟中学2019-2020学年高二语文9月阶段调研测试试题【含解析】
江苏省苏州市常熟中学2019-2020学年高二语文9月阶段调研测试试题(含解析)本试卷分第I卷(阅读题)和第Ⅱ卷(表达题)两部分。
共150分。
考试时间150分钟。
第I卷阅读一、现代文同读(36分)(一)论述类文本阅读(9分)阅读下面的文字,完成下面小题。
①中国古代乡村社会普遍存在的祠堂,是古代中国人慎终追远的重要场所,彰显着“敬宗收族、亲亲有爱”的礼之精神。
祠堂以血缘之基,融道德、信仰、礼三者于一体,规范礼制,聚族祭祀先人,团结族人,表达共同的精神寄托。
②古代的“宗族”,是指有宗子,行宗法制而聚合成的“血缘—政治”团体。
宋代程颐倡导士大夫阶层的宗族祭祀,到南宋朱熹制作《家礼》,提出了“祠堂”这一名词,确定了祠堂祭祀的格局。
一个家族祭拜先祖,由宗子主持祭祀,叫敬宗;一个家族由宗子率领祭祀共同的先祖,即收族。
宋明之后,甚至出现了不设立宗子的“族”。
这样一个同族同姓的村落,尽管没有“宗”,仍然可以被称为“宗族”,这个时期的宗族制度,就成了“血缘—社会”团体。
敬宗收族,使宗法不仅成为人与人之间的人伦共同体,而且成为生者与死者交通的人神共同体,具有重要的政治与社会功能。
③祠堂的功能之一是祭祀宗族祖先或先贤。
祠堂祭祀有多种,有季祭、节祭等。
不管豪门或寒族,对祭祀都十分重视,仪式庄严,礼节隆重。
祭祀先人是为了教育后人,立约族规是为了惩治违规犯律行为,借祖宗之威,禀祖宗之训。
在祭祀中,族长要宣读族规和家训以及族谱,族长在此代祖宗立言,宣讲传统伦理,告诫和惩罚犯错子孙。
凡做了错事的族人须站在特定的位置祭拜,寓意“低人一等”,以这样的方式来惩戒不良行为。
祭毕,后辈向前辈行礼,族人之间相互行礼,这样,祠堂祭祀就成了一种精神联系的纽带。
在这样的潜移默化中,家族成员从儿童期就受孝悌之礼等熏陶。
祭祀活动既加强了血缘关系,又强化了家族内部的向心力,从而对族中成员的行为起到榜样或约束作用。
④祠堂的动文化(祭祀)体现着祠堂的功能,祠堂的静文化(建筑装饰)也暗示或渗透着祠堂的功能。
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江苏省常熟中学2019-2020学年高二英语六月质量检测试题第I卷选择题(共75分)2020.6第一部分听力(共两节,满分20分)做题时,先将答案标在试卷上。
录音内容结束后,你将有两分钟的时间将试卷上的答案转涂到答题卡上。
第一节(共5小题;每小题1分,满分5分)听下面5段对话,每段对话后有一个小题。
从题中所给的A、B、C三个选项中选出最佳选项,并标在试卷的相应位置。
听完每段对话后,你都有10秒钟的时间来回答有关小题和阅读下一小题。
每段对话仅读一遍。
1. What does the man ask the woman to do?A. Fasten the locks.B. Carry the suitcase.C. Help to close the suitcase.2. How much did the woman pay?A. $60.B. $75.C. $15.3. What will the woman probably give the man?A. Her new address.B. Her mobile phone.C. Her mobile phone number.4. When will the man probably get back?A. On Thursday.B. On Friday.C. On Sunday.5. Who is ill?A. Jack's daughter.B. Jack's mother.C. Jack's wife.第二节(共15小题;每小题1分,满分15分)听下面5段对话或独白。
每段对话或独白后有几个小题,从题中所给的A、B、C三个选项中选出最佳选项。
听每段对话或独白前,你将有时间阅读各个小题,每小题5秒钟;听完后,各小题将给出5秒钟的作答时间。
每段对话或独白读两遍。
听第6段材料,回答第6、7题。
6. What are the speakers mainly talking about?A. A budget problem.B. A study problem.C. Part-time jobs.7. What will the woman do?A. Work more,B. Spend less money.C. Ask the man for help. 听第7段材料,回答第8至10题。
8. What is the probable relationship between the speakers?A. Salesperson and customer.B. Manager and clerk.C. Husband and wife.9. How will the woman go back?A. By coach.B. By air.C. By train.10. Where will the woman be staying?A. In a hotel near Hyde Park.B. In a hotel in the east side of London.C. In a hotel with an indoor swimming pool.听第8段材料,回答第11至13题。
11. What is the woman?A. A TV reporter.B. A newspaper reporter.C. A magazine reporter.12. What kind of clothes is the man wearing now?A. A suit.B. Casuals.C. Sportswear.13. What is the man's attitude towards his image?A. He cares little about it.B. He doesn't mind it.C. He cares much about it. 听第9段材料,回答第14至17题。
14. What does the man phone for?A. Greeting his mother.B. Borrowing money.C. Asking for his mother's advice.15. What advice does the woman give the man?A. He should go home tonight.B. He shouldn't buy another computer.C. He should use his money properly.16. What will happen this evening?A. The man will get another computer.B. The man will call for a chat.C. The man will get home.17. Who is probably Lily?A. The man's girlfriend.B. The man's sister.C. The man's niece.听第10段材料,回答第18至20题。
18. Where did the story take place?A. In a desert.B. Ina forest.C. In Hollywood.19. How did the old native American man help the film director?A. He directed him to the right way.B. He sponsored him a lot of money.C. He predicted the weather exactly.20. Why couldn't the old native American man help any more?A. He fell ill.B. His radio didn't work.C. He lost his magic power.第二部分阅读理解第一节(共12小题;每小题2.5分,满分30分)请阅读下列短文,从短文后各题多给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。
AThe new garbage sorting regulation has taken effect in Shanghai starting July 1. Many citizens are still confused about the classification of the four different types of trash. Thankfully, authorities have released an official guideline to clarify the new rules.The guideline, published by the Shanghai Greenery and Public Sanitation Bureau, provides a rather clear definition on the four kinds of waste: recyclable waste, hazardous (有害的)waste, household food waste and residual (剩余的)waste.Hazardous waste, as the name suggests, includes assorted poisonous materials like used batteries, light bulbs, out-of-date medicines, paint and pesticides.Household food waste, which is translated to "wet trash” in Chinese, refers to food leftovers, rotten food, pet food, fruit peels, remains of TCM herbs (中药)and flowers.Paper, plastic, glass, metal and textiles (纺织品)are counted as recyclable waste.The definition of residual waste is a little confusing. Anything that is not listed above belongs in this category.As specific as the new guideline is, residents still have a hard time sorting trash correctly and are finding it challenging to memorize them all. For instance, both plastic bottles and bubble tea or coffee cups are plastic materials. However, the former falls to the category of recyclable waste and the latter belongs to residual waste. To save the hassle, some netizens have come up with their own ways to sort trash."We should do this from a pig's angle,” commented one netizen. "Those edible (可食用的)for pigs are household food waste. Those even pigs don't want to eat are residual waste. If a pig consumes something and dies of it, then something must be hazardous waste. Those which can be sold and the money we gain can be used to purchase pigs are recyclable waste." The new regulation has gone into effect on July 1. Those who do not sort their trash properly will be fined RMB200.21. What do the old thrown-away sweaters belong to?A. Residual waste.B. Hazardous waste.C. Recyclable waste.D. Household food waste.22. What does “wet trash” have in common?A. They are completely wet.B. They all come from plants.C. They can give off bad smell.D. They can be broken down easily.23. What is the tone of the netizens?A. Humorous.B. Serious.C. Delightful.D. Uncertain.24. What is the main idea of the text?A. Shanghai bans four sorts of garbage.B. Shanghai launches garbage sorting enforcement.C. Citizens in Shanghai still question garbage sorting.D. Citizens in Shanghai welcome the garbage sorting policy.BBill Gates on how to fight future pandemicsWHEN HISTORIANS write the book on the covid-19 pandemic, what we've lived through so far will probably take up only the first third or so. The bulk of the story will be what happens next.I believe that humanity will beat this pandemic, but only when most of the population is vaccinated(接种疫苗).Until then, life will not return to normal.As the pandemic slows in developed nations, it will accelerate in developing ones. Their experience, however, will be worse. In poorer countries, where fewer jobs can be done remotely, distancing measures won't work as well. The virus will spread quickly, and health systems won't be able to care for the infected.Wealthy nations can help. But people in rich and poor places alike will be safe only oncewe have an effective medical solution for this virus, which means a vaccine.My hope is that, by the second half of 2021, facilities around the world will be manufacturing a vaccine. If that's the case, it will be a history-making achievement: the fastest humankind has ever gone from recognizing a new disease to immunizing (免疫)against it.Apart from this progress in vaccines, two other big medical breakthroughs will emerge from the pandemic. One will be in the field of diagnostics. The next time a novel virus crops up, people will probably be able to test for it at home. Researchers could have such a test ready within a few months of identifying a new disease.The third breakthrough will be in antiviral drugs. We haven't been as effective at developing drugs to fight viruses as we have those to fight bacteria. But that will change. Researchers will develop large diverse libraries of antivirals, which they'll be able to scan trough and quickly find effective treatments for novel viruses.All three technologies will prepare us for the next pandemic by allowing us to intervene (干预)early when the number of cases is still very low.Our progress won't be in science alone. It will also be in our ability to make sure everyone benefits from that science. In the years after 2021, I think we'll learn from the years after 1945. With the end of the Second World War, leaders built international institutions like the UN to prevent more conflicts. After covid-19, leaders will prepare institutions to prevent the next pandemic.These will be a mix of national, regional and global organizations. I expect they will participate in regular "germ games" in the same way as armed forces take part in War games. These will keep us ready for the next time a novel virus jumps from bats or birds to humans.I hope wealthy nations include poorer ones in these preparations, especially by devoting more foreign aid to building up their primary health-care systems. This pandemic has shown us that viruses don't obey border laws and that we are all connected biologically by a network of microscopic germs, whether we like it or not.The best analogy(类比)for today might be November 10th 1942.Britain had just won itsfirst land victory of the war, and Winston Churchill declared in a speech: "This is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning.25. What are the three technologies that will prepare us for the next pandemic?①manufacturing a vaccine fast②diagnosing a virus at home③developing antiviral drugs④allowing us to intervene earlyA.①②③B.①②④C.①③④D.②③④26. As far as poorer countries are concerned, which of the following is TRUE according to this passage?A. pandemic disease is more likely to begin in poorer countriesB. Working from home can work well in poorer countries.C. Health systems are sufficient to care for the infected in poorer countries.D. Virus will cross borders if poorer countries fail to contain it.27. Why is the Second World War mentioned in Para.9?A. The fight against the COVID-19 is similar to the Second World War.B. People are suffering just as they were in the Second World War.C. We should cooperate globally just as we did after the Second World War.D. Countries are fighting each other like in the Second World War.28. What is the tone of this passage?A. pessimisticB. optimisticC. neutralD. indifferentCI'm Dina Asher-Smith. Growing in Orpington, southeast London, I love being the hunter. The one in pursuit. In training, I'll latch on to the boys and chase them down. Even when I was younger, I tended to race girls who were older than me-at 17 I was racing 30-year-olds. It's where I'm comfortable. But the hunter can go on to become the hunted. And this year at the World Athletics Championships in Doha, Qatar, I won gold in the 200m. At 23,1 became the first British woman to win a world championship sprinting (短跑)title. The morning after the race, I was in the media tent and was told that I'd been mentioned in the ParliamentTrack and field is a mental game. You're in your own little world, competing to be the person who can run the fastest in a straight line. My job is to take my body to a place where I think it can't do any more and then keep going. To do that, I need to know my strengths and weaknesses. People get caught up in embarrassment or shame when they're not good at something, but I just don't have that in me. I do have a voice in my head that tells me if I'm not good at things, but it doesn't make me feel negative about myself I use it to identify where I can improve and then I just keep going to training every day.I've inherited personality traits from my parents that help me in my career. My mum is excitable and when I'm on the track, I have her fire-wanting to go for everything. I always know when I finish a race that I can turn around and find her in the front row, jumping up and down. My dad is more reserved. He has a cool exterior and that's useful for me when I need calmness. I know to look for him a few rows behind my mum. They gave me opportunities to try whatever I was interested in. When I wanted to try golf my dad bought me cut-down clubs and had me attempting to putt balls (推球入洞)in the back garden. My mum used to play hockey with me outside the house. They took me to so many clubs and classes.I started training with my coach, John Blackie, in my mid-teens. We met when I was eight as he ran the kids academy at my running club. Along with my parents, the three of them always emphasized that they just wanted me to be happy. They never pushed me too early. And, as I've got older, I've realized that's unique. When running became serious, I knew that if it all stopped being fun for me, I could stop doing it. They put Dina the person before Dina the runner. Yes, the public might be disappointed and the newspapers might have a pop(抨击),but my parents and friends are still going to love me, and my coach is still going to be there. That knowledgeallows me to stay relaxed under pressure.Being as prepared as I can be is crucial as it keeps me calm and able to deliver in the moment. When I was studying history at university, I'd choose exams over coursework because I knew I could put the work in and perform under pressure. I was studying heavy things every day, like people facing prejudice because of their skin, or women sacrificing their lives for others to have the right to vote. It made me realize how lucky I am that the thing that gets me most frustrated is somebody beating me on the track. While, yes, I make sacrifices-some easy, such as not drinking and going out, and some harder, like restricting the food that I eat-ultimately, what I do is entertainment.Everyone's asking me about Tokyo Olympics, but I'm more focused on today. It's important for me to keep my hopes and dreams separate from other people's. I'm grateful everybody wants me to do well, but my next step has to be for me, not anyone else.29. What does the underlined sentence in Paragraph 1 probably mean?A. Asher-Smith is the victim of the sprinting world.B. Asher-Smith becomes the focus of media coverage.C. Asher-Smith now runs faster than those she chased.D. Asher-Smith is no match for older racers in competitions.30. Paragraph 4 indicates that Asher-Smith's parents and coach .A. prioritize her personal well-beingB. justify her failure to continue runningC. put her interests above the other runnersD. shelter her from the criticism of the media31. What impact does her university life have on her?A. It makes her lead a cosy life today.B. It allows her to face prejudice bravelyC. It enables her to be better prepared as an athlete.D. It inspires her to fight for women's human rights.32.What does the passage mainly talk about?A. What it takes to be a gold medal sprinter.B. Why it is hard to rise to fame in sprinting.C. Who one can turn to in pursuit of the dream.D. How parents discipline a sprinting champion.第二节(共5小题;每小题2分,满分10分)根据短文内容,从短文后的选项中选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。