2018高考译林版英语一轮复习讲义：第1部分 选修9 Units 1-2

Units 1－2

Ⅰ.写作单词——会拼写

1．content adj. 满意，满足，甘愿

2．owe v t. 归因于，归功于；欠……债3．affair n. 风流韵事；公共事务；事件4．stress v t. 强调；重读

n. 强调；重读，重音；压力5．sentence v t. 判刑

n. 判决，宣判

6．merry adj. 欢乐的，愉快的

→merrily ad v. 欢乐地，愉快地

7．settle v. 定居，停留，(使)平静

→settlement n. 定居点；定居；(问题的)解决→settler n. 移民

8．equip v t. 装备，配备

→equipment n. 装备，设备，用具

9．thrill n. 兴奋，激动

v t. 使非常兴奋、激动

→thrilled adj. 非常激动的，兴奋的

→thrilling adj. 令人激动的

10．consider v. 考虑，认为

→considering prep.& conj. 考虑到，鉴于

→considerable adj. 相当大(或多)的，值得重视的

→considerate adj. 关心的，体贴的

→consideration n. 考虑

11．associate v t. 联想，联系

adj. 非正式的；副职的

→association n. 联系；交往

12．appoint v t. 任命，委任；指定(时间、地点) →appointment n. 任命；约会

13．assist v. 帮助，援助

→assistance n. 帮助，援助

→assistant n. 助手，副手

14．count v. 计数，有价值

→countless adj. 无数的，数不清的15．absolute adj. 绝对的，完全的

→absolutely ad v. 绝对地，完全地

16．freeze v. (使)结冰，凝固

→freezing adj. 极冷的，冰冻的

ad v. 极冷地

→frozen adj. 冷冻的，冷藏的，冻僵的17．assess v. 评估，评价

→assessment n. 评估，评价

18．inspire v. 鼓舞，激励

→inspiration n. 灵感；启发灵感的人(或事物) 19．recreate v. 消遣

→recreation n. 娱乐，消遣

20．immigrate v i. 移居，移民

→immigration n. 移民，移居

→immigrant n. 移民

Ⅱ.阅读单词——要识记

2018高考物理一轮复习42机械振动新人教版

42机械振动 一、选择题(每小题均有多个选项符合题目要求) 1．如图所示是某一质点做简谐运动的图象，下列说法正确的是( ) A．在第1 s内，质点速度逐渐增大 B．在第1 s内，质点加速度逐渐增大 C．在第1 s内，质点的回复力逐渐增大 D．在第4 s内质点的动能逐渐增大 E．在第4 s内质点的机械能逐渐增大 2．铺设铁轨时，每两根钢轨接缝处都必须留有一定的间隙，匀速运行的列车经过轨端接缝处时，车轮就会受到一次冲击．由于每一根钢轨长度相等．所以这个冲击力是周期性的，列车受到周期性的冲击做受迫振动．普通钢轨长为12.6 m，列车固有振动周期为0.315 s．下列说法正确的是( ) A．列车的危险速率为20 m/s B．列车的危险速率为40 m/s C．列车过桥需要减速，是为了防止发生共振现象 D．列车运行的振动频率和列车的固有频率总是相等的 E．增加钢轨的长度有利于列车高速运行 3．一质点做简谐运动的图象如图所示，下列说法正确的是( ) A．质点振动的频率是4 Hz B．在10 s内质点经过的路程是20 cm C．第4 s末质点的速度最大 D．在t＝1 s和t＝3 s两时刻，质点的位移大小相等、方向相同 E．在t＝2 s和t＝6 s两时刻，质点的速度相同 4．甲、乙两弹簧振子的振动图象如图所示，则可知( ) A．两弹簧振子完全相同 B．两弹簧振子所受的回复力最大值之比F甲F乙＝2：1 C．振子甲的速度为零时，振子乙的速度最大 D．两振子的振动频率之比f甲f乙＝1：2 E．振子乙的速度为最大时，振子甲的速度不一定为零 二、非选择题 5．有两个同学利用假期分别去参观北大和南大的物理实验室，各自在那里利用先进的DIS系统较准确地探究了“单摆的周期T与摆长l的关系”，他们通过校园网交换实验数据，并由计算机绘制了T2－l图象，如图甲所示．去北大的同学所测实验结果对应的图线是

唐山一中2018届高三英语一轮复习课上检测卷(3)

高三年级课本复习Book3Unit1 课上检测卷 一、单词(每题3分；共30分) 1.(v.) 道歉(n.) 道歉 2.(n.) 信任;信仰→(v.) 相信;信任 3.(n.) 许可;允许→(v.)允许;许可 4.(adj.) 宗教的;信奉宗教的→(n.)宗教 5.(n.)农业;农学(ddj.)农业的 6.(n.)独立;自主→(adj.) 独立地;存主见的 7.(adj.) 明显的;显而易见的→(adv.) 明显地;显然 8.(adj.)充满活力的;精力充沛→(n.) 能量;精力;能源 9.(vt.) 赞美;钦佩;羡慕(n.)钦佩;羡慕→(adj.)令人钦佩的 10.(n.)起源;由来(adj.) 原始的;最初的;原创的(adv.)最初;起初;本来 二、短语(每题3分; 共30分) 1.发生 2.纪念；追念 3.盛装;打扮;装饰 4.期望;期待 5.好像 6.出现;到场 7.守信用;履行诺言8. 屏息;屏气 9.出发;动身;使爆炸10.使…想起… 三、单句语法填空(每题4分;共20分) 1.Although he didn't play well at first,he entertained a firm (believe)in final victory. 2.You need (permit) from the World Wide Web before you can access information. 3.She speaks English so well that her friends are filled with (admire). 4. (remind) not to miss the flight at 15:20,the manager set out for the airport in a hurry. 5. ---I often fall asleep at work. ---Why not drink some tea? Tea can keep you (energy). 四、短语填空(每题4分;共20分) 1.Once you have promised to do something,you should (守信用). 2.The government set up a monument (为了纪念)the heroes who died in the war. 3.Don't panic! Do you know how many times you need (被提醒)this? 4.The holiday we have been (期待)came at last. 5.You must (向...道歉)your teacher for being so rude.

2018年高考英语总复习微专题训练

Ⅰ.语境填词 1．The ________(manage) decided to choose a responsible person to perform the task. 2．Gathering clouds ________(announce) the oncoming storm. 3．Smith said he is ________(innocence)，but many people think he is lying. 4．Now it became ________(evidence) that he spoke two languages at once. 5．He must be made to answer for these terrible ________(犯罪)． Ⅱ.单项填空 6．—Bob’s ________ the branches from the tree.Go and ________ for firewood.Bill!

—Do you think I’m really ________ for this kind of work? A．cut away；cut them up；cut through B．cut off；cut them down；cut through C．cut away；cut them up；cut out D．cut off；cut them down；cut out 7．—How are you going to ________ these problems? —I really don’t know what to ________.Will you help me out? A．deal with；do with B．deal with；do C．do with；do with D．do with；do 8．The word “ungelivable” based on Chinese，which has become a big hit online very quickly，________ a message that Chinese can also serve as an addition to English vocabulary. A．delivers B．simplifies C．declares D．clarifies 9．If you have any doubts about your health，you’d better________ your doctor at once. A．convince B．consult C．avoid D．affect 10．The company has got ________ from many users both at home and abroad for top-quality products and services.(2016·无锡一模) A．benefit B．apology C．credit D．envy Ⅰ.阅读理解 (2016·苏州一模) The newspaper must provide for the reader the facts，pure，unprejudiced，objectively selected facts.But in these days of complex news it must provide more；it must supply interpretation，the meaning of the facts.This is the most important

2018届高考英语(译林版)总复习真题研练40(有解析)

Task 1：阅读下面短文，从短文后各题所给的四个选项(A、B、C和D)中，选出可以填入空白处的最佳选项。 (2016·全国Ⅰ) A Heroic Driver Larry works with Transport Drivers，Inc.One morning in 2009，Larry was __1__ along 165 north after delivering to one of his__2__.Suddenly，he saw a car with its bright lights on.__3__he got closer，he found __4__vehicle upside down on the road.One more look and he noticed__5__shooting out from under the__6__https://www.wendangku.net/doc/e47989869.html,rry pulled over，set the brake and__7__the fire extinguisher (灭火器)．Two good bursts from the extinguisher and the fire was put out. The man who had his bright lights on__8__and told Larry he had__9__an emergency call.They__10__ heard a woman's voice coming from the wrecked (毁坏的) vehicle.__11__the vehicle，they saw that a woman was trying to get out of the broken window.They told her to stay__12__until the emergency personnel arrived，__13__she thought the car was going to__14__.Larry told her that he had already put out the fire and she should not move__15__she injured her neck. Once fire and emergency people arrived，Larry and the other man__16__and let them go to work.Then，Larry asked the__17__if he was needed or __18__ to go.They let him and the other man go. One thing is__19__—Larry went above and beyond the call of duty by getting so close to the burning vehicle! His__20__most likely saved the woman's life. 【语篇解读】这是一篇夹叙夹议文。短文讲述了货运司机拉里看到了一辆翻倒着火的汽车，不顾个人安危对伤者实施救助的故事。 1．A.walking B．touring C．traveling D．rushing 答案C[考查语境中动词的辨析。由下文的pulled over，set the brake等词可知，拉里送完货物之后正在道路上行驶。因此答案选C。] 2．A.passengers B．colleagues C．employers D．customers 答案D[考查语境中名词的辨析。拉里是送货司机，当然是将货物送到顾客(customers)手里。] 3．A.Since B．Although

2018版高考英语(人教通用)大一轮复习-满分必背+

必修一Unit 1Friendship Ⅰ.常考单词必背 1．upset adj.心烦意乱的；不安的；不适的vt.(upset，upset) 使不安；使心烦；打翻，碰倒；打乱 She was upset about losing her job. 她正为失去工作而心烦意乱。 Losing the ring upset her very much. 遗失戒指使她很心烦意乱。 [快速闪记] be upset about/over/at sth 为某事心烦 upset oneself about sth 为某事而烦恼 2．ignore vt.不理睬；忽视 Either she didn't see me wave or she ignored me on purpose.要么她没看见我招手，要么就是故意不理我。 [快速闪记] ignorant adj.不了解的，无知的 ignorance n．不了解，无知 3．concern vt.(使)担忧；涉及；关系到n．担心；关注；(利害)关系 The accident was concerned with the bus driver. 这次事故与公交车司机有关。 There is some cause for concern but no need for alarm. 是有点令人忧虑，但不必惊慌。 [快速闪记] concerned adj.担心的；关注的 be concerned about/for关心；担忧；挂念

be concerned with牵涉到……，与……有关 as/so far as...be concerned关于；至于；就……而言 4．power n．能力；力量；权力 The power was cut off and the street was entirely in darkness.断电后街道完全陷入了黑暗。 She was the one who had the power to hire or fire people.有权雇用或解雇人的是她。[快速闪记] (1)come to power上台，当权，表示动作，不能和一段时间连用。 (2)be in power当权，执政，表示状态，可以和一段时间连用。 (3)have the power to do sth 具有做某事的能力、权力 beyond/out of one's power某人力所不能及 5．settle vi.安家；定居；停留vt.使定居；安排；解决 They calmed down and settled their problem soon. 他们镇静下来并很快把问题解决了。 Mr.Wang settled down in America soon after he got there.王先生到美国后不久就定居下来了。 [快速闪记] (1)settle down舒适地坐下；安静下来；定居下来 settle down to sth/doing sth开始认真对待某事；定下心来做某事 (2)settlement n．解决；协议 6．suffer vt.& vi.遭受；忍受；经历 We'll suffer hunger one day if we don't care about the farmland.如果我们不关注农田，将来我们会挨饿的。 [快速闪记] suffering n．痛苦；苦难sufferer n．患病者；受难者 7．pack vi.& vt.捆扎；包装；打行李n．小包；包裹 As soon as I graduated，I packed my bags and moved to the west of China.一毕业我就收拾行李去了中国西部。 A pack of reporters were waiting outside for the latest news.一群记者在外面等待最

2018高考物理大一轮复习全真模拟试题精编(十)

2018年高考物理全真模拟试题（十） 满分110分，时间60分钟 第Ⅰ卷(选择题共48分) 选择题：本题共8小题，每小题6分．在每小题给出的四个选项中，第1～4题只有一项符合题目要求，第5～8题有多项符合题目要求．全部选对的得6分，选对但不全的得3分，有选错的得0分． 1．下列说法正确的是() A．自然界的电荷只有两种，库仑把它们命名为正电荷和负电荷 B．欧姆发现了电流的热效应 C．楞次根据通电螺线管的磁场和条形磁铁的磁场的相似性，提出了分子电流假说D．电流的单位“安培”是国际单位制中的基本单位 2．如图所示，静止在水平地面上倾角为θ的光滑斜面体上，有一斜劈A，A的上表面水平且放有一斜劈B，B的上表面上有一物块C，A、B、C一起沿斜面匀加速下滑．已知A、B、C的质量均为m，重力加速度为g.下列说法正确的是() A．A、B间摩擦力为零 B．C可能只受两个力作用 C．A加速度大小为g cos θ D．斜面体受到地面的摩擦力为零 3．如图所示，真空中两个等量异种点电荷＋q(q＞0)和－q以相同角速度绕O点在纸面中沿逆时针方向匀速转动，O点离＋q较近，则() A．O点的磁感应强度方向始终垂直纸面向外 B．O点的磁感应强度方向始终垂直纸面向里 C．O点的磁感应强度方向随时间周期性变化 D．O点的磁感应强度大小随时间周期性变化 4．如图甲所示，以等腰直角三角形ABC为边界的有界匀强磁场垂直于纸面向里，一个等腰直角三角形线框abc的直角边ab的长是AB长的一半，线框abc在纸面内，线框的cb 边与磁场边界BC在同一直线上，现在让线框匀速地向右通过磁场区域，速度始终平行于BC边，则在线框穿过磁场的过程中，线框中产生的电流随时间变化的关系图象是(设电流沿顺时针方向为正)()

2018高考英语一轮复习构想 Unit 1 Art课时作业 新人教版选修6

Unit 1 Art Ⅰ.阅读理解 A Here I will introduce some books to you. Cook Yourself Young By (author) Elizabeth Peyton-Jones Want to look and feel 10 years younger? Keen to remove bags under your eyes, and other unpleasant symptoms of ageing? Long to lose weight and stay slim? All you need is to change what you eat and to COOK YOURSELF YOUNG. In her revolutionary new book, Cook Yourself Young, a health expert Elizabeth Peyton-Jones explains how simply by changing the way you cook you can make yourself look younger and live a healthier, more balanced life. Celebrations and Special Days By (author) Ellen Lawrence In Celebrations and Special Days, young readers will join children around the world as they celebrate religious festivals and special family days, such as weddings and coming of age ceremonies. From Holi to Hanukkah, Easter to Ramadan, readers will join families as they prepare special meals, decorate their homes, and take part in the special times that shape our lives. The Story of the Lost Child By (author) Elena Ferrante “Nothing quite like this has ever been published before，” said The Guardian newspaper about the Neapolitan Novels in 2014, “Those Who Leave and Those Who Stay, the third book in the series, was an international bestseller and a New York Times Notable Book of the Year.” Its author was considered as one of the greatest novelists of our time by the New York Times Book Review. This fourth and final installment in the series raises the bar even higher and indeed confirms Elena Ferrante as one of the world's best living storytellers. 【解题导语】本文是说明文，介绍了三本书的相关信息。 1．Which book should you buy if you want to look young? A. Cook Yourself Young. B. Celebrations and Special Days. C. The Story of the Lost Child. D. New York Times Book Review. 答案与解析：A 考查细节理解。根据Cook Yourself Young部分最后一句中的“by changing the way you cook you can make yourself look younger”可知，Cook Yourself Young这本书介绍了如何通过健康的饮食来使人们保持年轻，故A项正确。 2．Who is Celebrations and Special Days intended for? A. Old people. B. All the people. C. Young people. D. Middle-aged people. 答案与解析：C 考查细节理解。根据Celebrations and Special Days部分第一句中的“In Celebrations and Special Days, young readers will join children around the world”可知，Celebrations and Special Days这本书的阅读对象是年轻人，故C项正确。 3．What can we learn about Elena Ferrante? A. She is the greatest novelist in the US. B. Her books sell best at the present time. C. She is the author of Celebrations and Special Days. D. She belongs to the best living storytellers. 答案与解析：D 考查推理判断。根据最后一段中的“and indeed confirms Elena

2018年高考英语复习题大全134

. --- Now day has ______. --- OK. We have been staying up the whole night. A. begun B. gone C. lighted D. broken . He never gives himself any rest; he’s always at ______. A. those B. it C. himself D. that . _____ was known to them that Bob had broken his promise _____ he would give them a rise. A. What; what B. It; which C. As; that D. It; that . She keeps a supply of candles in the kitchen in case of power ______. A. drop B. lack C. failure D. absence . I think that he must be looking up the information in the library, ______? A. isn’t he B. don’t I C. do you D. must he . It doesn’t make ______ to buy that expensive coat when these cheaper ones are just as good. A. decision B. promise C. sense D. peace . Miss Smith is a friend of ______. A. Mary’s mother’s B. the mother of Mary C. mother of Mary’s D. Mary’s of mother . The dog, _____, will be made a good watchdog. A. to train properly B. being trained properly C. properly to train D. trained properly . The -storeyed building, when _____, will shut out the sun _____ up the rooms in my house. A. completed; lighted B. completing; lighting C. completing; lighted D. completed; lighting . He is rather difficult to make friends with, but his friendship, _____, is more true than any other. A. once gained B. when to gain C. after gaining D. while gaining . _____ two years to looking after her mother, she badly needed a holiday. A. Devoted

2018届高考英语(译林版)总复习真题研练68 Word版含解析

Task 1：阅读下列材料，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。 (2015·浙江，C)If humans were truly at home under the light of the moon and stars，we would go in darkness happily，the midnight world as visible to us as it is to the vast number of nocturnal(夜间活动的) species on this planet.Instead，we are diurnal creatures，with eyes adapted to living in the sun's light.This is a basic evolutionary fact，even though most of us don't think of ourselves as diurnal beings.Yet it's the only way to explain what we've done to the night：We've engineered it to receive us by filling it with light. The benefits of this kind of engineering come with consequences—called light pollution—whose effects scientists are only now beginning to study.Light pollution is largely the result of bad lighting design，which allows artificial light to shine outward and upward into the sky.Ill-designed lighting washes out the darkness of night and completely changes the light levels—and light rhythms—to which many forms of life，including ourselves，have adapted.Wherever human light spills into the natural world，some aspect of life is affected. In most cities the sky looks as though it has been emptied of stars，leaving behind a vacant haze (霾) that mirrors our fear of the dark.We've grown so used to this orange haze that the original glory of an unlit night—dark enough for the planet Venus to throw shadows on Earth—is wholly beyond our experience，beyond memory almost. We've lit up the night as if it were an unoccupied country，when nothing could be further from the truth.Among mammals alone，the number of nocturnal species is astonishing.Light is a powerful biological force，and on many species it acts as a magnet(磁铁)．The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on la nd or by the light from gas flares on marine oil platforms.Migrating at night，birds tend to collide with brightly lit tall buildings.

2018届高考英语一轮复习阶段综合检测四4

阶段综合检测(四) (时间：100分钟满分：100分) 班级________姓名________得分________ 选择题部分(共65分) 第一部分：英语知识运用(共两节，满分35分) 第一节：单项填空(共15小题；每小题1分，满分15分) 从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。 ()https://www.wendangku.net/doc/e47989869.html,k ________ by five pence per pound. A．is risen B．is raised C．has risen D．has lifted ()2.The output of machines in 2005 is ________ it was in 2002. A． 5 times what B．5 times that C．5 times as many D．5 times of ()3.It is reported that the employment situation in east China ________ in the last two months, with a rebound in monthly figures. A．has improved B．improved C．was improved D．was improving ()4.The computer was used in teaching. As a result, not only ________， but students became more interested in the lessons. A．saved was teachers' energy B．was teachers' energy saved C．teachers' energy was saved D．was saved teachers' energy ()5.—I'm sorry. I ________ at you the other day. —Forget it. I was a bit out of control myself. A．should't shout B．should't have shouted C．mustn't shout D．mustn't have shouted ()6.—Has the doctor ________ the weak child ________ his illness? —No, the doctor didn't ________ him. A．cured; for; treat B．cured; of; treat C．cured; for; cure D．cured; of; cure ()7.(2016·苏北四市联 考)New version of Paris climate agreement ________， the whole world has seen a promising future of lower planet-warming greenhouse gas emissions. A．releasing B．released C．has released D．has been released ()8.Don't forget you can get ________ when you're swimming. A．burning B．burnt C．being burnt D．to be burnt ()9.________ the technology developing, the games will become more and more ________. A．As; amazing B．Of; amazed C．With; amazing D．For; amazed

【高三英语试题精选】2018届高三英语专项复习题：Unit 1 Disneyland

2018届高三英语专项复习题：Unit 1 Disneyland Do you remember ___ he came? -- Yes, I do He came by car A ho B when C that D if 6 It is generally considered unwise to give a child ____ he or she wants A however B whatever C whichever D whenever 7The reporter said that the UFO _____ east to west when he sait A was travelling B travelled C had been travelling D was to travel 8 A puter can only do _____ you have instructed it to do A ho B after C what Dwhen KeysDCAAABAC 二、阅读理解 AWalt Disney Walt Disney died in 1966, but hid work and his dreams did not die A negeneration of children watched his animal movies such as Snohite and even his old Mickey Mouse cartoons These are the sane Disney creations the parents and grandparents of these children enjoyed Millions of people also came to the United states to enjoy Disneyland in California and Disney World But although Disney’s work was extraordinary, in many ways Walt Disney was an ordinary man He was born in Chicago and had a rather typical childhood in the Midwest his family was not rich or successful In fact, his father failed in business several times Walt had to work hard, but he did not mind He did not mind hard work, and he did not give up easily One summer Walt wanted a fob at the post office, but they told

通用版2018高考英语一轮复习第1部分基础知识解读Unit1Friendship.doc

Unit 1 Friendship Ⅰ.写作单词——会拼写 1．upset adj. 心烦意乱的；不安的；不适的 vt. 使不安；使心烦 2．ignore vt. 不理睬；忽视 3．calm vt.&vi. (使)平静；(使)镇定 adj. 平静的；镇静的；沉着的4．grateful adj. 感激的；表示谢意的5．loose adj. 松的；松开的 6．teenager n. 十几岁的青少年 7．power n. 能力；力量；权力 →powerful adj. 强大的；有力的 →powerless adj. 无力的 8．suffer vt.&vi. 遭受；忍受；经历 →suffering n. 折磨；苦难 9．recover vi.&vt. 痊愈；恢复；重新获得 →recovery n. 恢复；康复 10．entire adj. 整个的；完全的；全部的 →entirely adv. 完全地；全然地；整个地11．dust n. 灰尘 →dusty adj. 积满灰尘的 12．settle vt. 使定居；安排；解决 →settler n. 移居者；定居者 →settlement n. 解决；处理 13．concern vt. (使)担忧；涉及；关系到 n. 担心；关注；(利害)关系 →concerned adj. 担心的；忧虑的 →concerning prep. 关于；涉及 14．exact adj. 准确的；精密的；精确的

→exactly adv. 确实如此；正是；确切地15．agree vi. 同意 →agreement n. 协议；同意；一致 →disagree vi. 不同意 16．like vt. 喜欢 prep. 像；如同 →dislike n．&vt. 不喜欢；厌恶17．outdoor adj. 户外的；室外的 →outdoors adv. 在户外；在野外 n. 野外；郊外 →indoors adv. 在室内；进入户内 Ⅱ.阅读单词——要识记 18．curtain n．窗帘；门帘；幕布19．series n. 连续；系列 20．thunder vi. 打雷；雷鸣 n. 雷；雷声 21．tip n. 提示；技巧；尖；尖端；小费vt. 倾斜；翻倒 22．partner n. 伙伴；合作者；合伙人23．highway n. 公路；大路 24．item n. 项目；条款 25．swap vt.交换 高频短语——会默写 1．add up 合计 2．calm(...)down (使)平静下来；(使)镇定下来3．be concerned about 关心；挂念 4．go through 经历；经受；完成；仔细检查5．set down 记下；放下；登记 6．a series of 一连串的；一系列；一套7．on purpose 故意地；有目的地 8．at dusk 在黄昏时刻 9．face to face 面对面地

2018高考物理一轮总复习(人教版)课时作业22附解析

课时作业 (本栏目内容，在学生用书中以独立形式分册装订！) 一、选择题(1～6题为单项选择题，7～10题为多项选择题) 1. (2017·陕西安康二调)如图所示，对于电场线中的A、B、C三点，下列判断正确的是() A．A点的电势最低 B．B点的电场强度最大 C．同一正电荷在A、B两点受的电场力大小相等 D．同一负电荷在C点具有的电势能比在A点的大 解析：根据电场线的特点，沿着电场线方向电势逐渐降低，则φA>φC>φB，又知同一负电荷在电势越低处电势能越大，则同一负电荷在C点具有的电势能比在A点的大，所以A错误，D正确；因在同一电场中电场线越密，电场强度越大，则知A点电场强度最大，所以B错误；因电场中E A>E B，则同一正电荷在A、B 两点所受电场力关系为F A>F B，所以C错误。 答案： D 2. 如图，水平天花板下用长度相同的绝缘细线悬挂起来的两个相同的带电小球A、B，左边放一带正电的固定球P时，两悬线都保持竖直方向。下面说法正确的是() A．A球带正电，B球带负电，并且A球带电荷量较P球带电荷量大 B．A球带正电，B球带负电，并且A球带电荷量较P球带电荷量小 C．A球带负电，B球带正电，并且A球带电荷量较P球带电荷量小 D．A球带负电，B球带正电，并且A球带电荷量较P球带电荷量大 解析：A、B悬线都处于竖直方向，表明沿水平方向均处于平衡状态，由此可判断A球带负电，B球带正电，结合库仑定律知，A球带电荷量较P球带电荷量小。故选C。 答案： C 3.

将两个质量均为m 的小球a 、b 用绝缘细线相连，竖直悬挂于O 点，其中球a 带正电、电荷量为q ，球b 不带电，现加一电场强度方向平行竖直平面的匀强电场(没画出)，使整个装置处于平衡状态，且绷紧的绝缘细线Oa 与竖直方向的夹角为θ＝30°，如图所示，则所加匀强电场的电场强度大小可能为( ) A.mg 4q B ．mg q C.mg 2q D ． 3mg 4q 解析： 取小球a 、b 整体作为研究对象，则受重力2mg 、悬线拉力F T 和电场力F 作用处于平衡，此三力满足如图所示的三角形关系，由图知F 的最小值为2mg sin 30°＝mg ，由F ＝qE 知A 、C 、D 错，B 对。 答案： B 4．如图所示，一个绝缘圆环，当它的1 4均匀带电且电荷量为＋q 时，圆心O 处的电场强度大小为E ，现 使半圆ABC 均匀带电＋2q ，而另一半圆ADC 均匀带电－2q ，则圆心O 处的电场强度的大小和方向为( ) A ．22E ，方向由O 指向D B ．4E ，方向由O 指向D C ．22E ，方向由O 指向B D ．0 解析： 由题意可知，若14圆AB 带电荷量为q ，AB 在圆心处场强为E ，方向由O 指向CD 中点，若1 4圆 CD 带电荷量为－q ，CD 在圆心处的场强也是E ，且方向与14圆AB 在圆心处场强相同；同理，1 4圆BC 、AD 在圆心处的场强也是E ，方向由O 指向AD 中点。合成各场强可得，圆心O 处的场强大小为22E ，方向由O 指向D 。因此A 正确。 答案： A 5．(2017·内蒙古包头测评)如图甲所示，在某一电场中有一条直电场线，在电场线上取A 、B 两点，将一个电子由A 点以某一初速度释放，它能沿直线运动到B 点，且到达B 点时速度恰为零，电子运动的v -t 图象如图乙所示。则下列判断正确的是( )