5.将一磁铁缓慢或者迅速插到闭合线圈中的同一位置处，不发生变化的物理量是(　　　 )

A.磁通量的变化量　　　　　　　　　　　　　　　　　　　　　　　　 B.磁通量的变化率

C.感应电流　　　　　　　　　　　　　　　　　　　　　　　　　　 D.流过导体横截面的电荷量

4.下列说法正确的是( 　　)

A.运动电荷在磁感应强度不为零的地方，一定受到洛伦兹力作用

B.运动电荷在某处不受洛伦兹力作用，则该处的磁感应强度不一定为零

C.洛伦兹力既不能改变粒子的动能，也不能改变粒子的动量

D.洛伦兹力对带电粒子不做功

3．赤道上空某处有竖立天空的避雷针，当带正电的云层经过避雷针的上方时，避雷针受到磁场力方向(　　 )

A．向东　　　　 B．向南　　　　 C．向西　　　　 D．向北

2．如图1所示，条形磁铁放在桌面上，一条通电的直导线由S极的上端平移到N极的上端的过程中，导线保持与磁铁垂直，导线的通电方向如图示，则这个过程中磁铁受到的摩擦力(磁铁保持静止)( 　　)

A．为零　　 　　　　

B．方向由向左变为向右

C．方向保持不变　　　　

D．方向由向右变为向左

1.关于光的直线传播及其现象的说法和判断正确的是( 　　)

A.光总是沿直线传播的

B.太阳照在浓密的树林里，地面上常出现许多圆形的光斑，这一现象表明树林里叶间小孔的形状是圆的

C.医院外科手术中的无影灯的照明效果是没有影子

D.在地球上不可能同时出现日全食和日环食现象

2.改为与其意思相近的词

borrow---keep　 buy---have　 become---be

catch a cold---have a cold　 put on---wear

1.改为be的形式

leave---be away(from)

die---be dead　　 get up---be up

go to sleep---be asleep

finish/end/stop---be over

go to bed---be in bed　　

go there---be there

come back---be back

marry---be married

begin/start---be on

open---be open(adj.)

fall ill---be ill

fall asleep/ill/sick---be asleep/ill/sick

close---be closed　 sleep--- be asleep

turn on---be on　　 lose---be lose

come---be in/here　　 arrive---be in

come to---be at/in　　 put on---be on

become---be　　 join---be in/a member of

42.状语从句的用法]

状语从句

1 地点状语从句通常由where, wherever 引导。

　Where I live there are plenty of trees.　 我住的地方树很多。 　Wherever I am I will be thinking of you.　 不管我在哪里我都会想到你。

2 方式状语从句 通常由as, (just) as…so…, as if, as though引导。

1) as, (just) as…so…引导的方式状语从句通常位于主句后，但在(just) as…so…结构中位于句首，这时as从句带有比喻的含义，意思是"正如…"，"就像"，多用于正式文体，例如： 　Always do to the others as you would be done by. 希望人家怎样待你，你就要怎样待人。

　As water is to fish, so air is to man.　 我们离不开空气，犹如鱼儿离不开水。

2) as if, as though 　 两者的意义和用法相同，引出的状语从句谓语多用虚拟语气，表示与事实相反，有时也用陈述语气，表示所说情况是事实或实现的可能性较大。汉译常作"仿佛……似的"，"好像……似的"，例如：

　They completely ignore these facts as if (as though) they never existed. 　他们完全忽略了这些事实，就仿佛它不存在似的。(与事实相反，谓语用虚拟语气。)

　He looks as if (as though) he had been hit by lighting. 　他那样子就像被雷击了似的。(与事实相反，谓语用虚拟语气。)

　It looks as if the weather may pick up very soon. 看来天气很快就会好起来。(实现的可能性较大，谓语用陈述语气。)

　说明：as if / as though也可以引导一个分词短语、不定式短语或无动词短语，例如：

He stared at me as if seeing me for first time.他目不转睛地看着我，就像第一次看见我似的。 3 原因状语从句 比较：because, since, as和for

1)　because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。 　 I didn't go, because I was afraid. 　 Since /As the weather is so bad, we have to delay our journey.

2)　由because引导的从句如果放在句末，且前面有逗 号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。 　 He is absent today, because / for he is ill. 　 He must be ill, for he is absent today. 4 目的状语从句 可以由that, so that, in order that, lest, for fear that, in case等词引导，例如： 　 You must speak louder so that /in order that you can be heard by all. 　 He wrote the name down for fear that(lest) he should forget it. 　 Better take more clothes in case the weather is cold.

5 结果状语从句 常由so… that 或 such…that引导，掌握这两个句型，首先要了解so 和 such与其后的词的搭配规律。

比较：so和 such 　其规律由so与such的不同词性决定。such 是形容词，修饰名词或名词词组，so 是副词，只能修饰形容词或副词。 so 还可与表示数量的形容词many, few, much, little连用，形成固定搭配。

　so foolish　　　　such a fool　 　so nice a flower　　such a nice flower　 　so many / few flowers　 such nice flowers 　so much / little money. such rapid progress　 　so many people　　　such a lot of people　 ( so many 已成固定搭配，a lot of 虽相当于 many，但 a lot of 为名词性的，只能用such搭配。) 6 条件状语从句 连接词主要有 if, unless, as/so long as, on condition that 等。. 　if 引导的条件句有真实条件句和非真实条件句两种。非真实条件句已在虚拟语气中阐述。unless = if not.　 　 Let's go out for a walk unless you are too tired. 　 If you are not too tied, let's go out for a walk. 7 让步状语从句 though, although 　注意： 当有though, although时，后面的从句不能有but，但是 though 和yet可连用 　He is very old, but he still works very hard.　虽然他很老，但仍然努力地工作。 　Though the sore be healed, yet a scar may remain.伤口虽愈合，但伤疤留下了。 (谚语)

2)　as, though 引导的倒装句 　 as / though引导的让步从句必须表语或状语提前(形容词、副词、分词、实义动词提前)。 　Child as /though he was, he knew what was the right thing to do. 　= Though he was a small child, he knew what was the right thing to do.

注意： a.　句首名词不能带任何冠词。 　　b.　句首是实义动词，其他助动词放在主语后。如果实义动词有宾语和状语，随实义动词一起放在主语之前。 3)　ever if, even though.　即使We'll make a trip even though the weather is bad.

4) whether…or-　 不管……都Whether you believe it or not, it is true.

5)　"no matter +疑问词" 或"疑问词+后缀ever" No matter what happened, he would not mind. 　 替换：no matter what = whatever 　　 no matter who = whoever 　　 no matter when = whenever 　　 no matter where = wherever 　　 no matter which = whichever 　　 no matter how = however 　 注意：no matter 不能引导主语从句和宾语从句。 8 比较while, when, as 1)as, when 引导短暂性动作的动词。 　　 Just as / Just when / When I stopped my car, a man came up to me. 2)当从句的动作发生于主句动作之前，只能用when 引导这个从句，不可用as 或 while。 　　 When you have finished your work, you may have a rest. 3)从句表示"随时间推移"连词能用as，不用when 或while。 　　 As the day went on, the weather got worse.　日子一天天过去，天气越变越坏。

9 比较until和till 　此两个连词意义相同。肯定形式表示的意思是"做某事直至某时"，动词必须是延续性的。否定形式表达的意思是"直至某时才做某事"。动词为延续性或非延续性都可以。

1)Until可用于句首，而till通常不用于句首。 　Until you told me, I had heard nothing of what happened. 　直到你告诉我以前，出了什么事我一点也不知道。　 2)Until when 疑问句中，until要放在句首。 　 ---Until when are you staying?　你呆到什么时候？ 　 --- Until next Monday.　呆到下周一。　

注意：否定句可用另外两种句式表示。 (1)Not until …在句首，主句用倒装。 　Not until the early years of the 19th century did man know what heat is. 　直到19 世纪初，人类才知道热能是什么。 (2)　It is not until… that… 10 表示"一…就…"的结构 　hardly/scarcely…when/before, no sooner…than　和as soon as都可以表示"一…就…"的意思，例：

　I had hardly / scarcely got home when it began to rain. 　I had no sooner got home than it began to rain. 　As soon as I got home, it began to rain.

注意：如果hardly, scarcely 或no sooner置于句首，句子必须用倒装结构： 　Hardly / Scarcely had I got home when it began to rain. 　No sooner had I got home than it began to rain.

[非延续性动词转换成延续性动词的表达法:]

非延续性动词转换成延续性动词的表达法:

1.情态动词的语法特征

　1) 情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。 　2) 情态动词 除ought 和have 外，后面只能接不带to 的不定式。 　3) 情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。 　4) 情态动词没有非谓语形式，即没有不定式，分词，等形式。

2 比较can 和be able to 1)can　could 表示能力；可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。 　They will be able to tell you the news soon. 他很快就能告诉你消息了。

2)只用be able to 　 a. 位于助动词后。 　 b. 情态动词后。 　 c. 表示过去某时刻动作时。 　 d. 用于句首表示条件。 　 e. 表示成功地做了某事时，只能用was/were able to， 不能用could。 　　He was able to flee Europe before the war broke out. 　= He managed to flee Europe before the war broke out. 注意：could不表示时态

1)提出委婉的请求，(注意在回答中不可用could)。 　 --- Could I have the television on?--- Yes, you can. / No, you can't.

2)在否定，疑问句中表示推测或怀疑。 　　 He couldn't be a bad man.　他不大可能是坏人。 3 比较may和might 1) 表示允许或请求；表示没有把握的推测；may 放在句首，表示祝愿。 　　May God bless you!　 He might be at home. 注意： might 表示推测时，不表示时态。只是可能性比may 小。

2) 成语： may/might as well，后面接不带to 的不定式，意为"不妨"。 　　 If that is the case, we may as well try.

典型例题 　Peter ___come with us tonight, but he isn't very sure yet. 　 A. must　B. may　 C. can　 D. will 　答案B. 表可能性只能用may.　此句意可从后半句推出。 4 比较have to和must　 1)　两词都是'必须'的意思，have to 表示客观的需要， must 表示说话人主观上的看法，既主观上的必要。 　My brother was very ill, so I had to call the doctor in the middle of the night.　我弟弟病得很厉害，我只得半夜里把医生请来。(客观上需要做这件事) 　He said that they must work hard. 他说他们必须努力工作。(主观上要做这件事)

2)　have to有人称、数、时态的变化，而must只有一种形式。但must 可用于间接引语中表示过去的必要或义务。 He had to look after his sister yesterday.

3) 在否定结构中： don't have to　 表示"不必" 　　　　　mustn't　　表示"禁止"， 　 You don't have to tell him about it.　 你不一定要把此事告诉他。 　 You mustn't tell him about it.　　你一定不要把这件事告诉他。 5 must表示推测 　1) must用在肯定句中表示较有把握的推测，意为"一定"。 　2) must表对现在的状态或现在正发生的事情的推测时， must 后面通常接系动词be 的原形或行为动词的进行式。 You have worked hard all day.You must be tired.　 你辛苦干一整天，一定累了。(对现在情况的推测判断) 　　He must be working in his office. 他一定在办公室工作呢。

　比较： 　　 He must be staying there.　他现在肯定呆在那里。 　　 He must stay there. 他必须呆在那。 　3) must 表示对已发生的事情的推测时，must 要接完成式。 I didn't hear the phone. I must have been asleep.　我刚才没有听到电话，我想必是睡着了。

　4) must表示对过去某时正发生的事情的推测，must 后面要接不定式的完成进行式。 　---Why didn't you answer my phone call? 　---Well, I must have been sleeping, so I didn't hear it.

　5) 否定推测用can't。 　 If Tom didn't leave here until five o'clock, he can't be home yet.　如果汤姆五点才离开这儿，他此时一定还未到家。 6 表示推测的用法 　can, could, may, might, must 皆可表示推测，其用法如下：

1)情态动词+动词原形。 　表示对现在或将来的情况的推测，此时动词通常为系动词。 　I don't know where she is, she may be in Wuhan. 2)情态动词+动词现在进行时。 　表示对现在或将来正在进行的情况进行推测。 　At this moment, our teacher must be correcting our exam papers. 　这时，我们老师想必在批改试卷。

3)情态动词+动词完成时。 　表示对过去情况的推测。 　We would have finished this work by the end of next December. 　明年十二月底前我们很可能已完成这项工作了。 　The road is wet. It must have rained last night. 　地是湿的，昨天晚上一定下雨了。

4)情态动词+动词的现在完成进行时。 　表示对过去正在发生事情的推测。 　Your mother must have been looking for you. 　你妈妈一定一直在找你。

5)推测的否定形式，疑问形式用can't, couldn't表示。 　Mike can't have found his car, for he came to work by bus this morning. 　迈克一定还没有找回他的车，因为早上他是坐公共汽车来上班的。

　注意：could, might表示推测时不表示时态，其推测的程度不如can, may。 7 情态动词+ have +过去分词 1) may(might) have + done sth, can (could) have + done sth　表示过去，推测过去时间里可能发生的事情。 　Philip may (might) have been hurt seriously in the car accident. 　Philip can (could) have been hurt seriously in the car accident.

2)　must have +done sth，对过去时间里可能发生的事情的推测，语气较强，具有"肯定"，"谅必"的意思。 　---Linda has gone to work, but her bicycle is still here. 　---She must have gone by bus.

3) ought to have done sth, should have done sth 　本应该做某事，而事实上并没有做。否定句表示"不该做某事而做了"。 　You ought to (should) have been more careful in this experiment. 　He ought not to have thrown the old clothes away.(事实上已扔了。) 　ought to 在语气上比should 要强。

4) needn't have done sth　 本没必要做某事 　I dressed very warmly for the trip, but I　needn't have done so. The weather was hot.

5) would like to have done sth　 本打算做某事　 　I would like to have read the article, but I was very busy then.

8 should 和ought to　 　should 和ought to 都为"应该"的意思，可用于各种人称。 　---Ought he to go? 　---Yes. I think he ought to. 　表示要求，命令时，语气由 should(应该)、had better最好)、must(必须)渐强。 9 had better表示"最好" 　had better 相当于一个助动词，它只有一种形式，它后面要跟动词原形。 　had better do sth 　had better not do sth 　It is pretty cold. You'd better put on my coat. 　She'd better not play with the dog.

　had better have done sth表示与事实相反的结果，意为"本来最好"。 　You had better have come earlier.

10 would rather表示"宁愿" 　would rather do 　would rather not do 　would rather… than…　 宁愿……而不愿。

　还有would sooner, had rather, had sooner都表示"宁愿"、"宁可"的意思。

　If I have a choice, I had sooner not continue my studies at this school. 　I would rather stay here than go home. = I would stay here rather than go home. 典型例题 ----Shall we go skating or stay at home? ----Which ___ do?　　　 A. do you rather　B. would you rather　 C. will you rather　 D. should you rather 答案B。本题考查情态动词rather的用法，would rather +do sth 意为"宁愿"，本题为疑问句，would 提前，所以选B。 11 will和would 　注意： 　1)would like； Would like to do = want to 想要，为固定搭配。 　 Would you like to go with me? 　2)Will you…?　Would you like…? 表示肯定含义的请求劝说时，疑问句中一般用some, 而不是any。 　 Would you like some cake? 　3)否定结构中用will，一般不用would, won't you是一种委婉语气。 　 Won't you sit down?

12 情态动词的回答方式 　 问句　　肯定回答　　否定回答 Need you…?　Yes, I must.　　No,I needn't Must you…?　　　　　　/don't have to.

典型例题 1)---Could I borrow your dictionary? 　---Yes, of course, you____.　 　 A. might　B. will　 C. can　 D. should 　 答案C.could表示委婉的语气，并不为时态。答语中of course，表示肯定的语气，允许某人做某事时，用can和 may来表达，不能用could或might。复习： will 与you连用，用来提出要求或下命令。should与you 连用，用来提出劝告。

2)---Shall I tell John about it? 　---No, you ___. I've told him already.　 　 A. needn't　B. wouldn't　C. mustn't　D. shouldn't 　 答案A。needn't 不必，不用。 wouldn't 将不, 不会的。 mustn't 禁止、不能。 shouldn't　不应该。本题为不需要，不必的意思，应用needn't。

3)---Don't forget to come to my birthday party tomorrow. 　---______. 　A. I don't　 B.　I won't　 C. I can't　D. I haven't 　答案B.　will既可当作情态动词，表请求、建议、也可作为实义动词表"意愿、意志、决心"，本题表示决心，选B。 13 带to 的情态动词 　　 带to 的情态动词有四个：ought to, have to, used to, be to, 如加上have got to ,(=must), be able to，为六个。它们的疑问，否定形式应予以注意： 　 Do they have to pay their bill before the end of the month? 　 She didn't use to play tennis before she was fourteen. 　 You ought not to have told her all about it. 　 Ought he to see a heart specialist at once.?

　 ought to 本身作为情态动词使用。其他的词作为实义动词使用，变疑问，否定时，须有do 等助动词协助。

典型例题 　Tom ought not to ___ me your secret, but he meant no harm.　 　A.have told　B.tell　C.be telling　D. having told 　答案A。由于后句为过去时，告诉秘密的动作又发生在其前因，此地应用过去完成时，但它在情态动词 ought to 后，所以用have。 14 比较need和dare 　 这两词既可做实义动词用，又可做情态动词用。作为情态动词，两者都只能用于疑问句，否定句和条件句。 need 作实义动词时后面的不定式必须带to，而dare作实义动词用时, 后面的to 时常可以被省略。 1) 实义动词： need　(需要, 要求) 　　　　 need + n. / to do sth 2) 情态动词： need，只用原形need后加do，否定形式为need not。 　Need you go yet? 　Yes, I must. / No, I needn't. 3) need 的被动含义：need, want, require, worth(形容词)后面接doing也可以表示被动：　 　need doing = need to be done

40.take的用法]

take可作及物动词和不及物动词，主要有以下用法： 一、take作拿，拿走，带去讲。如： Please take the tea-things away. 请把茶具拿走。 You\'d better take your umbrella along. 你最好把雨伞带着。 二、take作"吃(喝)，乘坐，接受" 讲。如： She asked us to take tea with her. 她请我们和她一起喝茶。 We are waiting to take the plane to Yan\'an. 我们在等着乘飞机去延安。 I\'m very glad that you\'ve taken their advice. 我很高兴你接受了他们的建议。 三、take作"测量，照(相)，记录"讲。如： The doctor took my temperature. 医生量了我的体温。 We took photos on the Great Wall.我们在长城上照了相。 四、take作"花费，需要"讲。如： It takes many hands to do the work. 这项工作需要许多人去做。 五、take + n. 构成的词组：take effect生效，发生作用；take aim瞄准； take care当心，注意；take office就职； take trouble 费事；take notes作笔记；take pains费力；take place发生；take heart鼓起勇气。如： These measures are just beginning to take effect. 这些措施刚开始见效。 The player knelt down to take aim. 这位选手跪下来瞄准。 Take care that you don\'t slip. 当心别滑倒了。 Take notes, summarise and help the speaker decide. 作笔记，总结一下，然后帮助发言者作决定。 He took office at a most difficult time. 他是在极其困难的时候就职的。 六、take + adv.　 prep. 构成的词组：take away 拿走，拿开；take back 收回；take down拆开，记下；take in 欺骗，领会，包括，容纳；take off 起飞，成名，脱掉；take on呈现，接纳；take out取出，拔出；take up 学习，占去，从事，接纳；take over 接收，接管；take to 喜欢。 如： I should take back what I said. 我应该收回我说的话。 She was taken in at the railway station. 在火车站她被骗了。 Take off your wet shoes and come in. 脱掉湿鞋进来吧。 The plane took off at 8 a.m. 飞机是早晨8点起飞的。 The tour takes in some famous old castles. 这趟观光旅游包括若干著名的古堡。 七、take + n. + 介词构成的词组：take account of 考虑；take advantage of 利用；take care of 照顾，照管；take charge of 负责，管理；take hold of 抓住；take notice of 注意；take part in 参加；take pride in为......感到骄傲； take delight in乐于； take interest in对......感兴趣；take pity on同情。如： She soon took charge of the work. 她很快就负责这项工作了。 She took hold of the little tree. 她抓住了小树。 Take particular notice of that man. 要特别注意那个人。 He took part in the contest last month. 上个月他参加了竞赛。

[41情态动词的用法]