北师大版高中英语模块7 Unit 21 Human Biology 虚拟语气与情态动词

虚拟语气与情态动词
概念引入
虚拟语气是英语中三个语气之一，也是经常考查的语法项目之一，本单元我们将重点复习虚拟语气在if从句中的应用，并小结一下与虚拟语气关系紧密的情态动词的用法。先看下面句子：
1. Many contemporary amateur athletes would have broken world records if they had taken part in the first Olympic Games.
2. Ben Johnson would still be the 100 metres world record holder if he had not been caught taking drugs in the 1988 Olympics.
3. In the summer of 1996, everything must have been going perfectly for the twenty-five-year-old Texan cyclist.
4. There was 40% chance he would survive and a 60% chance he might die.
5. By the summer of 1999, he did not need to take any more medication and according to his doctors, was 98% “home” in his battle against cancer.
这些句子中的斜体词就是要讲的内容的具体应用。句1和句2中的是虚拟语气用在条件句中；句3和句4中的是情态动词的两种用法，而句5是即可作情态动词，又可以作实义动词的need的实义动词的用法。
用法讲解
虚拟语气（1）
if 引导的条件状语从句中的虚拟语气
英语中一般把条件句分为两种：真实条件句和非真实条件句。非真实条件句要用虚拟语气，表示说话人的愿望、假设、猜测或建议，而不表示客观存在的事实，根据与现在、过去及将来时间的事实相反的不同，其主句和从句的谓语有不同的形式，见下表：
主从句
时间
if 条件句
主句
与现在事实相反
动词过去式（be多用were）
would/should/could/might＋动词原形
与过去事实相反
had＋过去分词
would/should/could/might＋have＋过去分词
与将来事实相反
1. 动词过去式
2. should +动词原形
3. were to+动词原形
would/should/could/might＋动词原形
If I were a bird, I could fly to my hometown. （与现在事实相反）
如果我是一只鸟的话，我就能飞回家乡了。
If we had started earlier, we would not have missed the train. （与过去事实相反）
如果我们早点出发，就不会错过这列火车了。
What would happen if the earth should stop turning tomorrow? （与将来事实相反）
万一地球明天停止运转，会出现什么情况呢？
两点注意
1. 在 if 虚拟条件句中，如果谓语动词有were / should / had时，可以省略if，把were/should/had提到主语前，即条件从句要变为部分倒装句。
Were I at school again, I would study harder.
如果我可以再上学，我会更努力地学习。
Had you come earlier, you would have caught the bus.
如果你早一点到，你就会赶上那趟车了。
Should it rain (=Were it to rain), the crops would be saved.
如果下雨的话，庄稼就得救了。
2. 有时，句子没有直接给出假设情况的条件，而须通过上下文或介词短语等方式来表现的，如but for, without, or, but, otherwise等连接的介词短语和分句。
I would have come to see you, but I was too busy. 我本该来看你了，然而我太忙了。
But for his help, we would be working now. 要不是他的帮助，我们还会在工作呢。
Without your instruction, I would not have made such great progress.
要是没有你的指导，我不会取得如此大的进步。
虚拟语气（2）
混合虚拟条件句
虚拟条件句与主句所指的时间不一致(如一个是过去的，一个是现在的)，这时主、从句谓语动词的形式需要根据具体的时间来调整，从而构成混合虚拟条件句，即错综时间条件句。该句式中不仅仅存在时间的不同，更重要的是事实和假设的混合，其基本用法如下：
1．想象的过去事件可能对现在或将来有影响
If you had taken his advice then, you would be better now.
如果你当时听取了他的建议，你现在会好些。
If you hadn’t watched TV late last night, you wouldn’t be so sleepy now.
如果你昨晚看电视不看到那么晚，你现在就不会这么困倦。
2．想象的过去事件可能对现在正在进行的动作有影响
If I had studied hard, I would be studying in college now.
如果我努力学习的话，我现在就在大学里学习了。
If you had not given me a lift, I would be walking in the rain now.
如果你不让我搭车，我现在还冒雨走着呢。
3．非真实的常常是想象中的现在状态，可能对过去有影响
If I were you, I would have gone to Shanghai to watch the Expo then.
如果我是你，当时我就去上海看世博会了。
If she didn’t speak a few languages, she wouldn’t have got that job.
如果她不会说几种语言，她就不能得到那份工作了。
附：4种条件句----另一种分类方法
按照习惯，一般把条件句分成两种：真实条件句和非真实条件句。条件句还可以分成：零条件句、第一条件句、第二条件句和第三条件句，前两种属于真实条件句，后两种属于非真实条件句。
零条件句：描述一件事总是紧跟另一件事发生的规律和情景。（总是真实的）
If I don’t eat breakfast, I always get hungry during class.
如果我不吃早餐的话，上课时总饿。
第一条件句：用来谈论将来发生的事情，或用来提出建议、要求或命令。（将来可能）
If the rain stops，the match will begin. 雨停了比赛就开始。
第二条件句：用来谈论想象的，将来不可能发生的事情，或现在不可能的情况。
（现在或将来不可能）
If my brother were here, everything would be all right.
如果我兄弟在这里，一切都会顺利了。
第三条件句：表示过去不真实的情景，想象过去未发生的事情。（过去不真实的情况）
If he had seen you yesterday, he would have asked you about it.
虚拟条件句做题技巧
1. 记熟虚拟条件句不同时间时主句、从句谓语的形式。
2. 根据时间状语、上下文逻辑关系、上下文句意或已给出的主句或从句，分别判断主句和从句与哪一时间的事实相反，从而选择合适的谓语形式。例如：
1）Grace doesn’t want to move to New York because she thinks if she ________ there, she wouldn’t be able to see her parents very often.
A．lives B．would live C．has lived D．were to live
解析：主句“Grace doesn’t want to move to New York”说明Grace尚未搬到纽约，所以think的宾语从句表示的是对将来的虚拟，if引导的虚拟条件从句中可用过去式或“should＋动词原形”或“were to＋动词原形”，因此选D。
2）Had they known what was coming next, they ________ second thoughts.
A．may have B．could have C．must have had D．might have had
解析：根据“Had they known ...”和句意可知，此处是省略了if的条件句，表示与过去事实相反的假设，所以主句用should/would/could/might＋have done结构，故D项正确。
3）Maybe if I ______science, and not literature then, I would be able to give you more help.
A．studied B．would study C．had studied D．was studying
解析：主句中“would be able to...”表示对现在的假设，但由if从句中的then可知，从句表示对过去情况的虚拟，是混合虚拟条件句，所以选C。
3. 注意除了考查主从句的谓语形式外，有时也考查表示相关事实的句子的谓语动作的形式，这时要根据已给出的虚拟语气的形式来判断说明事实的句子的时态。例如：
I would have come earlier, but I ________ that you were waiting for me.
A. didn’t know B. hadn’t known C. would have known D. haven’t known
解析：从would have come earlier可知，这是一个省略了if从句的与过去事实相反的虚拟条件句，but后连接的是表示真实事实的句子，所以用一般过去时。选A。
其它虚拟语气
I. 类条件句型
1. as if, as though引导的方式状语从句和表语从句有时用虚拟语气。
从句谓语动词的结构为：
1）发生在主句动作之前：had + 过去分词
2）与主句动作同时发生：过去时(be 用were )
3）发生在主句动作之后：would / could / might / should+原形动词
They began to talk warmly as if they had known each other for long.
他们开始热烈的谈论起来，就好像他们已相互认识很久了。
He coughed twice as if someone would come.
他咳嗽两声就好像有人要来了。
It seems as if/ as though she were an American.
她像个美国人似的。
2. wish后接宾语从句时，从句谓语要用虚拟语气。
从句谓语动词的结构为：
1）发生在wish之前：had + 过去分词
2）与wish同时发生：过去时(be多用were)或would / could + have +过去分词
3）发生在wish之后：would / could +原形动词
注意：从句的形式与wish的时态无关。
I wish I were better looking. 要是我长得漂亮些就好了。
She wished she had stayed at home. 她多希望她当时留在家里了。
I wish you would go with us tomorrow. 要是你明天同我们一起去就好了。
I wished I were rich. 当时我多希望自己有钱。
3. if only与I wish一样，也用于表示与事实相反的愿望。
if only后所接虚拟语气的形式与if条件句所接形式相同。
If only she had had more courage! 她再勇敢一些就好了。
If only it would stop raining! 雨要是停了就好了。
If only he didn’t drive so fast. 但愿他车没开得那么快。
4. would/ should rather后接从句用虚拟语气。
从句谓语动词的形式：
1）一般过去时表示现在或将来的愿望。
2）用过去完成时表过去的愿望。
I’d rather you came next Saturday. 我宁愿你下星期六来。
—Shall I open the window? 我要不要把窗子打开?
—I’d rather you didn’t. 我看不要打开好。
I’d rather you hadn’t said it. 我真希望你没有这样说过。
Katie went by car and I’d rather she hadn’t. 凯蒂是坐汽车去的，我宁愿她不坐汽车去。
Ⅱ. “(should) +原形动词”型
1. advise, ask, demand, desire, decide, insist(坚决要求) , order, propose, request, suggest(建议), recommend(推荐), urge(力劝)等表示请求、要求、命令或建议等动词所接的宾语从句一般用虚拟语气，其虚拟语气的结构为：“(should) + 原形动词”，should可省。
The teacher advised that we should make good use of every minute here.
老师劝我们要好好地利用在这儿的每一分钟。
但是，当insist意为“坚决认为，坚持说”时，suggest意为“表明，暗含，暗示”时，宾语从句一般不用虚拟语气。
Tom insisted that he hadn’t stolen the watch. 汤姆坚持说他没有偷那块手表。
His smile suggested that he had succeeded in this exam. 他的微笑表明他考试考得很好。
2. 表语从句及同位语从句中虚拟语气
表示请求、要求、命令、建议等名词advice, desire, decision, idea, instruction, order, plan, proposal, recommendation, request, requirement, suggestion, wish充当句子的主语而后面接表语从句或它们后面接同位语时，表语从句及同位语从句多用虚拟语气。其虚拟语气的结构为：“(should) + 动词原形”，should可省。
We followed his advice that we should ask our teacher for help.
我们接受了他的建议：我们应该请求老师的帮助。
He told us his idea that he should go to university.
他告诉了我们他的想法：他想上大学。
His suggestion is that we should do our work more carefully.
他的建议就是我们的工作要更细心些。
Their plan is that they should build a new factory in their hometown.
他们的计划就是在家乡建一座新工厂。
3. 下面句型中的主语从句常用虚拟语气
从句谓语的结构：“(should) + 动词原形”，should可省。
1) It is/ was important (appropriate, desirable, necessary, etc.) that...
It is proper that an independent inquiry should take place. 进行独立调查很合适。
It is necessary that I should return it right now. 我有必要马上把它还回去。
2) It is/was amazing (strange, surprising, astonishing, a pity, a shame, a surprise, etc.) that...
表示说话人的惊异、懊悔、失望等情感，有“竟然”之意。
It’s strange that he should be so rude. 他竟如此无礼，真是奇怪。
It’s surprising that he should have failed. 他竟然失败了，真让人吃惊。
若不用虚拟语气也可以，则不带感彩，比较：
It’s a pity that he failed the exam. 他考试没及格，真是遗憾。
It’s a pity that he should have failed the exam. 他考试竟没及格，真是遗憾。
3) It is/ was suggested (requested, required, ordered, proposed, decided, etc.) that...
It was proposed that this matter be considered at the next meeting.
有人提议这事下次会议再讨论。
It is desired that this rule should be brought to the attention of the staff.
希望这条规则引起全体职员的注意。

Ⅲ. 定语从句中的虚拟语气
句型“It is (high / about) time that...”中的定语从句中的谓语动词须用虚拟语气：
结构：动词的过去式/ should + 动词原形（should不省略）
It is time that I went to pick up my daughter at school. 我该去学校接我的女儿了。
It is high time you should go to work. 你早该上班了。
Ⅳ. in order that, so that, for fear that, in case, lest等引导的目的状语从句的虚拟语气
从句的谓语动词形式为：should（may, might, can, could, would等）+动词原形
I gave her $100 in order that she might buy the bike she had wanted.
我给了她100美元，以便于她可能买她想要的自行车。
情态动词（1）
情态动词表示说话人的语气和情态，如需要、可能、愿意和怀疑等。情态动词有一定的词义，但不完整，必须和主要动词的原形一起构成谓语，常用的情态动词有：can, could, may, might, must, ought to, need, dare 以及shall, will, should, would；下面短语也表达情态动词的意义：be able to, be to do, had better, have to。
下面就从功能方面复习一下情态动词的具体用法。
1. 谈论义务和需要
1）must 必须（表示个人的观点）
2）have to 不得不（用于转述别人的观点，如老师的命令，规则等，有各种时态）
3）should，ought to 应该
4）shall（用于第二、三人称的陈述句，表示命令、警告、强制、威胁、决心等）
You must clean your teeth after every meal. 每次餐后你都应该刷牙。
We have to leave earlier to arrive on time. 我们不得不出发很早，以便准时到达。
Did you have to pay to go in the museum? 进入这家博物馆你必须付钱吗？
You shall apologize to him. 你要向他道歉。
2. 谈论允许和禁止
1）can/ could 2）may/ might
3）shall（用于第一、三人称的疑问句，用于征求对方的意见和指示）
4）will/ would (用于疑问句表示请求、邀请,would语气更委婉)
5) mustn’t /can’t （表示禁止）
You can’t play football in the street. 你不能在街上踢足球。
—Could I use your dictionary? 我能用一下你的词典吗？
—Yes, you can. 行，可以。
Shall I fetch some water for you? 要我去给你拿些水吗？
Will you see a movie with me? 你愿意和我去看电影吗？
Would you join us? 你愿意加入我们吗？(答语用will)
We mustn’t disturb them. 我们一定不要打扰他们。
They can’t tell me what to do. 他们不能告诉我该做什么。
3. 谈论无必要
1）don’t have to 2) needn’t（need用作情态动词，多用于否定句和疑问句）
We didn’t have to pay for the beer, it was free. 这些啤酒我们无需付钱，是免费的。
You needn’t bring any food, there’ll be enough. 你不需要带食物，会有足够的食物。
情态动词（2）
4. 谈论能力
can/ could 能够（可用be able to替换，was/ were able to还表示过去有能力而且运用能力做了某事，此时不能用could代替）
He can’t speak English.他不会讲英语。
My little daughter could sing and dance when she was two.
我女儿两岁时就会唱歌跳舞。
对比：He was able to swim across the river before he was tired out.
他筋疲力尽前得以能够游过了那条河。
5. 谈论可能性和猜想与猜测
1) can/ could 可能 (表推测?多用于疑问句和否定句，表示理论上的可能性时可用于肯定句)
Who can he be? 他会是谁呢？
John can’t see us in the crowd. 约翰不可能在人群中看见我们。
It can be very hot in our city in summer. 我们城市的夏天有时候会很热。（理论上的可能性）
2) may/ might 可能 (表推测多用于陈述句，might表示可能性更小些)
We may meet her at the station.我们可能会在车站遇到她。
He may not come to the party. 他可能不会来参加聚会。
Thinking it might rain, I decided to go in the car. 我当时以为会下雨，决定开车去。
3) must 一定（只用于肯定句）
There must be nobody in the room. 房间里一定没有人。
4) should/ ought to （按常理）应该
With her talent and experience — she should do well for herself.
凭着她的才能和经验，她自己应该能做得很好。
They ought to win — they’ve trained hard enough.
按道理说他们会赢——他们训练很刻苦。
5）will 会，将（表示趋势和预测）
They will have finished reading by now. 他们现在大概已读完了。
He’ll be late, as usual. 像平时一样，他会晚来的。
6. 做决定
will 将
I’ll talk to Jim about it. 我会与吉姆谈谈这件事。
I won’t go there. 我不会去那里。
情态动词（3）
Ⅰ. 某些情态动词的其他用法
1. may表祝愿
May you succeed！祝你成功！
2. must表示“偏要，硬要”，常指做令人不愉快的事。
Must you shout so loudly? 你非得这么大声吗？
3. should表示惊奇、怀疑、不满的情绪。
He should be careless to such an important matter. 他竟然对这么重要的事那么粗心。
4. will/ would
1）表意愿、意志、决心，可用于各种人称。
2）表示习惯性动作。
I’ve asked her but she won’t come. 我已经问过她，但她不愿意来。
I felt he would go with me. 我感觉他愿意和我去。
As a young man, he would play basketball. 小时候，他常常打篮球。
5. shall 用于第二、三人称，表示说话人的许诺。
Tell Jerry that he shall get a gift if he is nice. 告诉杰里，如果表现好，他会得到一份礼物。
2. 情态动词＋have done的用法
1）must have done 想必/准是/一定做了
It must have rained last night, for the road was quite muddy.
昨天晚上一定下雨了，因为路上非常泥泞。
2）can have done/ cannot have done 可能/不可能做过
The ground is very dry, so it can’t have rained last night.
地面很干燥，所以昨晚不可能下过雨。
Can he have gone to his aunt’s? 他可能去他姑姑家了吗？
3）may (not) have done 过去可能（没有）做过
He may not have finished the work. 他可能还没完成工作。
She might have caught a cold. 她也许感冒了。
4）could have done （肯定句中）本有能力做
You could have done better, but you were too careless.
你本可以做得更好，但是你太粗心了。
5) should/ ought to have done 本应该做（实际上没有做）
I should have studied hard, but it was too late. 我本应该努力学习，但是现在太晚了。
6) shouldn’t have done 本不应该做（实际上做了）
You shouldn’t have told her the truth. 你本不该告诉她实情的。
7) needn’t have done 本不需要做 （注意与didn’t need to do的区别）
didn’t need to do中的need是实义动词，所以要加do/did构成否定和疑问，后接动词时要加to do，表示“过去不需要做某事”。
needn’t have done中的need是情态动词，可以直接构成否定与疑问，后接动词时要接原形，接have done时，表示“本不需要做某事，结果做了”。
She didn’t need to play because the match was cancelled.
她不需要去打球，因为比赛取消了。（实际上也没有去）
We needn’t have brought any food to the party — there was plenty already.
我们本来不需要带食物去聚会，已经有很多了。（实际上“我们”带了）
巩固练习
Ⅰ. 用动词的适当形式填空。
If I had a dictionary, I ________ (lend) it to you yesterday.
If they ________ (study) hard, they would be college students now.
If Mary ________ (not be catch) in the rain that day, she ________ (not have) a fever now.
If I were you，I _________ (not miss) the film last night．
If you _________ (ask) him when you saw him last time，you _________ (know) what to do now．
If I__________ (not work) all night, I __________ (not feel) tired now.
Ⅱ. 单项选择。
1. I got close enough to hear them speaking Chinese, and I said “Ni Hao”, just as I ________ do in China.
A．must B．might C．can D．should
2. —________ you interrupt now? Can’t you see I’m on the phone?
—Sorry Sir, but it’s urgent.
A．Can B．Should C．Must D．Would
3. I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.
A．couldn’t B．mustn’t C．shouldn’t D．needn’t
4. One of our rules is that every student ________ wear school uniform while at school.
A．might B．could C．shall D．will
5. — Happy birthday!
—Thank you! It’s the best present I________ for.
A．should have wished B．must have wished
C．may have wished D．could have wished
6. We ________ have bought so much food now that Suzie won’t be with us for dinner.
A．may not B．needn’t C．can’t D．mustn’t
7. I’m going to Europe on vacation together with John if I ________ find the money.
A．can B．might C．would D．need
8. Miss Pei is on time for everything. How ________ it be ________ she was late for the opening ceremony?
A. must; where B. can; that C. should; when D. might; if
9. In fact, you ________ go outside at all. There’s a supermarket just downstairs.
A. couldn’t B. mustn’t C. needn’t D. shouldn’t
10. Can you imagine that a smart man like him ________ make such a stupid mistake?
A. might B. should C. would D. need
11. —It was the drug, rather than the disease, that killed the boy.
—He ________ still alive today if he ________ that drug.
A．would be; hadn’t taken B．is; didn’t take
C．would have been; hadn’t taken D．will be; hasn’t taken
12. Our former maths teacher moved to Beijing last year, otherwise, he ________ us.
A. would still have taught B. would still be teaching
C. will still teach D. should still teach
13. Sorry, I am too busy now. If I ________ time, I would certainly go for an outing with you.
A．have had B．had had C．have D．had
14. —Did Jack take the doctor’s advice that he _______ in bed for a couple of days?
—If only he________.
A．lies；does B．lay；did C．lie；did D．lie；had
15. —Sorry for having kept you waiting. But for the traffic jam，I________20 minutes earlier.
—Never mind. I haven’t been waiting that long.
A．arrived B．would arrive C．would have arrived D．had arrived
16. We ________ to the station because it was so near. But we took a taxi.
A．walked B．had walked C．could have walked D．had to
17. —I saw your uncle take a taxi to the airport. Why didn’t you drive him there?
—I ________. But my car________.
A．would；was fixed B．would have；was fixed
C．would have；was being fixed D．did；was being fixed
18. —Amazing！You ________ wear slippers at work!
—Don’t you know it’s a fashion?
A．must B．should C．can D．May
19. ________for the fact that she got hit by a car and broke her leg on her way to school，she might have passed the exam.
A．Had it not been B．Hadn’t it been C．Was it not D．Were it not
20. After the bell rings，which indicates the ending of the exam，you ________stay where you are until all your papers are collected.
A．shall B．would C．will D．can
Ⅲ.完成句子。
根据已给的汉语或英语提示，完成句子。
1.如果他遵照医生的劝告，现在病就好了。
If he _________ the doctor’s advice, he would recover already．
2.如果我当时在学校用功读书，我现在就有一个更好的工作了。
If I ________ harder at school, I ________ a better job now.
3.如果我不害怕蜘蛛的话，我就会把它抓起来的。
If I wasn’t afraid of spiders, I _________ it up.
4.要是他们一大早就出发的话，再过半个小时就该到了。
If they had started in the early morning, they _________ in half an hour．
5.如果昨晚下雨的话，今天就要凉快些了。
If it ________ last night, it _________ cooler today.
6. You didn’t have any breakfast, so you are hungry now.
If you _______ breakfast, you _______ hungry now.
7. You didn’t listen to the teacher, so you can’t work out the maths problem now.
If you ________ to the teacher, you _________ the maths problem now.
8. He hurt his legs in the last training, so he will not take part in the coming running race.
If he________ his legs, he _________ the coming running race.
Ⅳ. 翻译短文。
今天我们埋葬了我们的二十一岁的儿子。他于星期五晚上在一场摩托车事故中当场死去。我是多么希望在我们上一次谈话的最后一刻知道将要发生这样的事，倘若我知道我一定会对他说“吉姆，我爱你，我为你感到非常骄傲。”我应该早点抓紧时间去认真回味他每一次带给那些爱他的人的祝福，我应该抓紧时间去仔细回味他那美丽的微笑，他笑的声音，那种纯真的爱，那种对别人纯洁无暇的爱。
答案与解析：
Ⅰ. 用动词的适当形式填空。
1. would have lent 2. had studied 3. hadn’t been caught; would not have
4. wouldn’t have missed 5. had asked; would know 6. hadn’t worked; wouldn’t feel
Ⅱ. 单项选择。
1. B。句意：我尽量靠近他们以便听见他们说汉语，而且我会像我在中国可能做的那样说“你好”。might表示“可能”。故选B。
2. C。句意：“你偏要现在打扰我吗？难道你没有看到我正在打电话吗？”“对不起，先生，但是情况太紧急了。”must表示“偏要，硬要”。选C项。
3. D。句意：我不需要用闹钟叫我起床，因为每天早上六点都会有一列火车经过我家门口。应选“不需要”，即needn’t。
4. C。句意：我们的一条规定是学生在校时都必须要穿校服。shall用于第二、三人称，表示说话人给对方命令、警告、允诺或威胁。
5. D。句意：谢谢你！这是我所能期望的最好的礼物了。could have wished意为“过去可能希望”，符合句意。
6. B。注意后面的now that从句：Suzie不与我们一起吃饭。所以前面是在说我们本没有必要买那么多食物。needn’t have done表示某事已经做了，但后来觉得没必要去做，因此常含有责备或遗憾之意，常译成“本来不必……”，句意：我们本来不必买这么多食物的，因为Suzie不与我们一起吃饭。
7. A。句意：如果我能弄到钱，我就和John一起去欧洲度假。结合前后部分的内容可知，此处表示的是能力。故用can“能，会”。
8. B。can表示可能性的推测，常用于疑问句或否定句中；may表“可能性”常用于肯定句或否定句中；must常用于肯定句中表推测，意为“一定……”，所以选B。第二空用that引导形式主语it所代替的主语从句。
9. C。根据下文“楼下就有超市”，所以填needn’t，表示“没有必要”。couldn’t表示“不能”，指过去没有能力；mustn’t表示“禁止”，意为“一定不要”；shouldn’t意为“不应该”。
10. B。句意：你能想象一个像他这样的聪明人竟然犯这样的愚蠢的错误吗？根据句意，选B。should此处用于表示惊讶，意为“竟然”。
11. A。考查混合条件句。从句与过去情况相反(根据第一句话可知)，主句与现在情况相反(根据today可知)，故选A项。
12. B。考查含蓄条件句和混合条件句。otherwise表示的含蓄条件，相当于if he hadn’t moved to Beijing last year, 但结果不是过去的情况，而是现在的情况，为错综条件句。句意：我们以前的数学老师去年搬到北京去了，否则，他现在会仍然教我们。
13. D。句意：抱歉，我现在太忙了。如果我有时间的话，我会和你一起外出郊游。由句意可知，是对现在的事实的假设，所以if从句用一般过去时态。
14. D。句意：——杰克是否采纳了医生的建议，在家里躺了几天？——要是他真那样做就好了。第一空考查advice的同位语从句，从句中的谓语用(should＋)动词原形，所以选lie；第二空if only表示“但愿……，要是……的话就好了”，其后用虚拟语气，根据Did Jack...可知与过去事实相反，故选had，相当于“If only he had taken...”。
15. C。句意：——很抱歉让你久等了。若不是交通堵塞，我就提前20分钟到了。——没关系，我没等那么久。but for若不是因为，如果没有。依句意可知，此句是一个与过去事实相反的虚拟语气，所以主句用would have done，因此选C。
16. C。句意：我们本来可以走着去车站的，因为非常近，但是我们坐的出租车。could have done过去本来能够做某事。
17. C。句意：——我看到你叔叔打的去了机场，你为什么不开车去送他呢？——我本愿意去送他，但我的车当时正在修理。would表示“现在或将来愿意”，故被排除；did表示“的确做了”，不符合句意，排除；would have表示“过去本愿意”，符合要求；第二空表示“我的车当时正被修理”，需用过去进行时。
18. B。句意为：——真奇怪！你竟然穿着拖鞋上班。——难道你不知道这是一种时尚吗？should表示“竟然”，其他选项不能表示此意。
19. A。句意：要不是因为在上学的路上被汽车撞了且腿部骨折，她可能就通过考试了。根据句意及主句谓语动词形式可知从句是与过去事实相反的虚拟语气，故答案为A。
20. A。句意：当标志着考试结束的铃响后，你们必须等试卷全部被收起来后。shall用于第二人称，表示“命令”。
Ⅲ. 完成句子。
1. had followed 2. had studied; would have 3. would have picked
4. would arrive 5. had rained; would be 6. had had; wouldn’t be
7. had listened; could work out 8. hadn’t hurt; would take part in
Ⅳ. 翻译短文。
Today we buried our 20-year-old son. He was killed in a motorcycle accident on Friday night. How I wish I had known when I talked to him last that it would be the last time. If I had only known I would have said, “Jim, I love you and I’m very proud of you.”
I would have taken the time to count the many blessings he brought to the lives of the many who loved him. I would have taken time to appreciate his beautiful smile, the sound of his laughter, his genuine love of people.