should ? ??

The parents were suprised to find their so-called good girl ___ have skipped classes once for a while. A.would B.might C.must D.should

解题思路： 理解含义
解题过程：
The parents were suprised to find their so-called good girl ___ have skipped classes once for a while.
A.would B.might C.must D.should
选D
本句意为：该父母吃惊的发现他们的所谓的好女儿竟然偶尔逃课。
should此处意为竟然的意思。
以下是关于情态动词的总结，供您学习
情态动词
情态动词
情态动词表示说话人的语气和情绪，本身词义不全，不能单独作谓语，后面必须与动词原形一起构成谓语。情态动词没有人称和数的变化，有的情态动词有过去式。常见的情态动词有can, could, may, might, must, have to, shall, should, will, would, ought to, need, dare, used to等。
一、 情态动词的基本用法
(一) can, could的用法
1．表示体力或脑力(知识、技能)所产生的能力。
Her mother can speak French.
He could read books in English when he was only five.
2．表示理论上的可能性。
Anybody can make mistakes.
Man can not live without air.
3．表示请求建议，用could 比 can语气更委婉。(回答用原形)
Could you wait a few days for the money?
Could you be here at eight o'clock tomorrow morning?
4．表示允许、许可，用could 比 can更委婉客气。
Could/Can I borrow your reference books?
You can smoke in the entrance hall.
【疑难点击】
1. 否定句、疑问句和感叹句中，表示怀疑、惊异、不相信的态度。
Can it be true?
You can't be serious!
Oh, dear, what on earth can this mean?
2. 表示“经过努力后终于能……”用be able to。
They were able to put out the fire without any help from the firefighters.
【疑难点击】
3. 惯用形式“can not (can't)…too/over/enough”。表示“无论怎么……也不(过分)”，用来加强语气。can not but do sth. 不得不；只好。
You can not be too careful.
I couldn't but choose to wait.
(二) may, might的用法
1. 表示允许、请求。
Might I…？ 比 May I…？ 语气更为委婉和有礼貌。
— May I ask you a question?
— Yes, please.
— May I watch TV after supper?
— Yes, you may.或No, you may not/ You'd better not./ You mustn't.(强烈的禁止语气)
2. 表示可能性，表示“或许”，“大概”。用于肯定句或否定句中，用might 比 may语气更加不肯定。
He may be very busy these days.
He might come tomorrow.
【疑难点击】
1. may, might用于目的状语从句中，含“为了……”或“以便……”之意。
Study hard that you may work better in the future.
They set out early so that they might arrive in time.
2. 惯用形式 may (might)as well＋动词原形：不妨做……
If that is the case, we may as well try.
Now that they were all here, she might as well speak her mind.
【疑难点击】
3. 表示祝愿(不用might)。采用部分倒装语序：may＋主语＋动词原形＋……！
May you succeed!
May the friendship between our two peoples last forever!
(三)must，have to的用法
1. must 表示“必须”。强调主观看法，只有现在时形式，否定式是must not(mustn't)，表示“禁止”，“不准”。
Everybody must obey the rules.
You mustn't speak like that to your mother.
— Must I be home before eight o'clock?
— Yes, you must. / — No, you needn't./No, you don't have to.
2. must表示有把握的推测，意为“一定，肯定”，用于肯定句中。　　
You must be hungry after the long walk.
Home cooking must be more delicious.
3. have to表示“必须，不得不”，着重强调客观需要，能用于更多时态(过去式和将来式)。
The students today will have to know how to use computers.
As he had broken his leg, he had to lie in bed.
【疑难点击】
must 有“偏要、硬要”之意。
— How old are you, madam?
— If you must know, I'm twice my son's age.
(四)will，would的用法
1. 用于各种人称，表示意志或决心。will指现在，would则指过去。
I will do my best to help you.
They said that they would help us.
2. 用于第二人称的疑问句中表示有礼貌的询问和请求，would 比 will更委婉。
Would you teach us how to drive a car?
Will you please give him a message when you see him?
3. 表示习惯性、经常性、倾向性，意为“总是”，“惯于”。 will指现在，would指过去。
Fish will die without water.
He will sit for hours reading.
He would come to see me on Sunday when he was in Beijing.
【疑难点击】
1. 表示说话人的推测，意为“大概，也许”。would 的肯定性不如will强，语气比较弱。
That will be the man you want to see.
Perhaps she would be willing to meet us.
2. 在if ,when ,until等连词引导的表示时间或条件的从句中要用一般时表将来，但在if 从句中有时为了表示意愿也可用will ，有“愿意”的意思。例如：
1) If you will read this article ,you will realize you are wrong.
2) If they won’t help us ,we can not finish the task within one month.
3. 如主语为物，则意为“不起作用”。如：
The drawer won't shut.
抽屉关不上了。
My fountain pen wouldn't write.
我的自来水笔不能写字了。
【疑难点击】
3. would 与used to 的区别：
①used to 表示过去的某种习惯，现在已经没那样的习惯了；would 表示过去有某种习惯，现在可能还有。
②表示过去的状态，只能用used to，不能用would。
There used to be a park here.
(五)shall，should, ought to的用法
1. shall用于第一、第三人称作主语的疑问句中，表示征求对方意见或请求指示。
Shall I turn off the light?
Shall he come in?
2. should 表示“应该”，表义务，责任，也可表示劝告，建议。
You should keep your promise.
I should help him because he is in trouble now.
Young people should be polite.
3. should表示按常规、常理推测，意为“可能”或“应该”。
They should arrive by one o'clock.
Mother should be back by now.
4. 提出意见、请求、建议时，可用should表示委婉、谦逊的语气，意为“可”，“倒是”。
Should you like some tea?
I should think you are mistaken.
5. ought to表示责任和义务，意为“应该”，语气比 should强；还可表推测。
You ought to finish your work before you go home.
You ought to obey your parents when they are right.
You have practiced for a long time. There ought to be no difficulty for you.
【疑难点击】
1. shall 用于第二、三人称作主语的陈述句中，表示说话人的决心、意志、许诺、命令、警告、威胁等。
You shall go with me.
I promise you shall see them again.
You shall not leave your post.
2. Why/How ＋should结构表示说话人对某事不能理解、感到意外、惊异等意思，意为“竟会”。
Why should you be so late?
你今天来得怎么这么晚？
How should I know?
我怎会知道！(意为：我不知道。)
3. should表示意外或惊讶 It’s strange that he should come so late. 他竟然来这么迟真是奇怪。 I’m sorry that this should have happened. 我很遗憾竟然发生这种事。 I’m surprised that he should say so. 他竟这样说，这使我很惊讶。
(六)need的用法
1. need作情态动词表示“需要”，“必要”。通常用于否定句、疑问句、条件句中，且只有现在时，其他时态用“have to”的相应形式代替。
You needn't water the tomato plants now.
— Need he come now?
— Yes, he must. / No, he needn't / he doesn't have to.
2. need还可以用作行为动词，其变化和一般的动词相同。若主语为动作承受者时用动词主动形式表示被动意义或用不定式的被动形式。　　
We need to have a rest.
The house needs repairing.
＝The house needs to be repaired.
(七)dare的用法
1. dare作情态动词表示“敢于”，用于否定句、疑问句和条件句中。
She dare not go there.
How dare he do such a thing?
2. 惯用短语“I dare say”意为“我想，大概”。
I dare say he is right.
3. dare还可以用作行为动词，其变化与一般动词相同。
The girl didn't dare to go home.
Do you dare to jump into the ocean?
I don't dare (to) ask her.
【注意】在否定句中时，dare后的“to＋动词原形”可以省略to。
二、情态动词的其他用法
情态动词除各自有自己的词义外，还可以表示猜测和责备(虚拟)等意义。
(一)情态动词表推测的用法
can /must/may/should这四个情态动词可以用于推测，可以对现在状态、现在正在进行的动作、过去已经发生的动作或对将来发生的动作进行推测。
1．对现在状态、现在正在进行的动作的推测，用“情态动词＋动词原形”结构，不同用法如下：
(1) can
can用于否定句：意为“不可能”。
The door is locked. He can not have got home.
(2) may
(1)用于肯定句，意为“也许，可能”(might 的可能性更小)。用于否定句，意为“也许不/没有，可能不/没有”(注意与can't 否定猜测时意思的对比)。
He has a car. He may come by car, but I am not sure.
No one comes to answer the phone. He may not be at home.
(3) must
只能用于“肯定句”表示猜测，意为：“肯定，必定”(＝I am sure that…)。
(4) should/ought to
用于肯定句，意为 “理应，应当”(按常规、常理、风俗习惯等进行推测)。
It's spring now. It should be warm.
The new coat ought to be ready on Thursday.
2．对过去所发生的事情的推测，用“情态动词＋完成式”结构，不同用法如下：
(1) must have done 一定做过某事。
There's no light in the room. They must have gone to bed.
(2) cannot have done 表示对过去所发生的行为的怀疑和不肯定。
(3) could have done 本来可以做而实际上未做。
You could have done the work better.
你本来可以把工作做得更好一些的。
(4) may/might have done 也许/或许已经…… ；本来可能……(但实际上没有发生)；本来应该或可以做某事(含有轻微的责备语气)。
He may not have finished the work.
他或许没有完成这项工作。
He might have given you more help, even though he was very busy.
他也许可以给你更多的帮助，尽管他很忙。
(5) should / ought to have done 本来应该做而实际上未做。
You ought to have done the exercise more carefully.
你本应该更加仔细地做这个练习。
You should have been here five minutes ago.
你本来应该5分钟以前到这儿。
(6) ought not to have done/shouldn't have done本来不应该做（而实际上做了）
needn't have done 本来不必做某事
We shouldn't have waited for her because she never came.
我们本来就不必等她，因为她从未来过。
You needn't have come over yourself. You could have given me a ring instead.
你本来不必亲自来，只要给我通个电话就行了。
【疑难点击】
1. 当must作“必须”意义时，其反意部分用needn‘t; 当含有mustn’t时，其反意部分用must/may；
You must go now, needn't you?
You mustn't smoke here, must/may you?
2. 当情态动词表推测时，反意部分的动词形式根据情态动词后面所隐含的时间来确定。
You must be hungry now, aren't you?
You must have heard about it, haven't you?
You must have watched that football match last night, didn't you? 同学：不知这样的解答您能否满意，如有不同意见，请在下面的继续讨论中留言好吗？赵君老师愿意与您再次进行亲切的交流。匆忙中难免有疏漏，请多包涵哦。祝：学习不断进步，开心每一天！
最终答案：略