(A) needn't to come (B) don't need come (C) don't need coming (D)needn't come
11. ___ you be here at eight o'clock tomorrow morning?
(A) Would (B) Should (C) Can (D) Could
12. ___ I have a talk with the Party Secretary now?
(A) Will (B) Did (C) May (D) Can
13. "You ___ read that article if you don’t want to.”
(A) needn't (B) mustn’t (C) haven't (D) can’t
14. When the storm comes all windows ___.
(A) ought to close (B) ought to be closing (C) ought to be closed (D) ought to closed
15. I ___ me what happened.
(A) would like you tell (B) would like you to tell
(C) would like you telling (D) would like you that you tell
16. I hope you can visit my country soon, because___ to show you some of the beautiful places near my home.
(A) I like (B) I'd like (C) I will like (D) I shall like
17. She ___ for yesterday's test, but she didn’t.
(A)should have studied (B) would study (C) might be studying (D)must have studied
18. He ___ breakfast at eight o'clock when he lived alone. But nowadays he ___ it at seven.
(A) was used to have ... is having (B) was used to having ...is having
(C) used to have ... has (D) used to having ...was
19. In the old society Grandpa Zhou ___ to work long hours a day.
(A) was working (B) was having (C) had (D) has
20. Everybody ___ in bed.
(A) has to spend some time (B) have to spend some time
(C) has to spend sometimes (D) have to spend sometimes
2) 选择合适的词或词组填空
1. I have a headache. I __________ take an aspirin.
(had better; would better)
2. He looks sleepy. He must __________ bed very late last night.
(go; have gone)
3. I want to go to the office, but you __________ with me.
(need not to go; need not go)
4. I ought __________ those books to the library last week.
(to have taken; to take)
5. The mother is telling her son, “You __________ eat with your fingers!”
(wouldn’t; mustn’t)
6. He was a good swimmer so he _______ swim to the river bank when the boat sank. (was able to; could)
7. To travel from England to Scotland you __________ a passport.
(don’t need; needn’t)
8. He went on foot, but he __________ by bus.
(ought have gone; should have gone)
9. A: Did Ken take the job in the bookstore?
B: No, but I think he __________.
(must have; should have)
10. He __________ talk for hours, if you let him.
(can; will)
11. You __________ use this toothbrush, it’s mine.
(may not; shall not)
12. No matter what people say, I __________ do as I like.
(shall; will)
13. “I’m willing to let you take whatever you like.” Means “you ______ take whatever you like.” (shall; will)
14. A: I haven’t felt well for a week.
B: You __________ see a doctor.
(had better; should have to)
15. A: He is late, __________ he have missed the bus?
B: Yes, he must have missed the bus.
(Can; Must)
二、强化练习
1) 选择填空
1. I didn’t see her in the meeting room this morning. She _____ at the meeting.
A. mustn’t have spoken B. shouldn’t have spoken
C. needn’t have spoken D. couldn’t have spoken
2. One ought _____ for what one hasn’t done.
A. not to be punished B. to not be punished
C. to not punished D. not be punished
3. If you really want yourself to be in good health, you must ___ always ___ so much.
A. not; be smoking B. not; have smoked
C. not; to smoke D. be not; smoking
4. With so much work on hand, you _____ to see the game last night.
A. mustn’t go B. shouldn’t go C. couldn’t have gone D. shouldn’t have gone
5. Most of the students felt rather disappointed at the English party. They say that it ______ better organized.
A. had been B. had to be C. must have been D. could have been
6. I’m surprised that he _____ in the exam.
A. should fail B. would have failed C. may have failed D. should have failed
7. The little girl _____ there alone.
A. not dare go B. dares not go C. dare not go D. dare not to go
8. “Must we do it now?” “No, you _____.”
A. won’t B. needn’t C. can’t D. don’t
9. He said he would rather not _____ it right now.
A. doing B. to do C. do D. to be doing
10. You _____ to the meeting this afternoon if you have something important to do.
A. needn’t to come B. don’t need come C. don’t need coming D. needn’t come
11. Put on more clothes. You _____ be feeling cold with only a shirt on.
A. can B. could C. would D. must
12. I _____ play football than baseball.
A. would rather B. had better C. like better D. prefer
13. I thought you _____ like something to read, so I have brought you some books.
A. may B. might C. could D. must
14. There was plenty of times. She _____.
A. mustn’t have hurried B. couldn’t have hurried
C. must not hurry D. needn’t have hurried
15. The plant is dead. I _____ it more water.
A. will give B. would have given C. must give D. should have given
16. You _____ return the book now. You can keep it till next week if you like.
A. can’t B. mustn’t C. needn’t D. may not
17. It’s still early, you _____.
A. mustn’t hurry B. wouldn’t hurry C. may not hurry D. don’t have to hurry
18. Please open the window, _____?
A. can’t you B. aren’t you C. do you D. will you
19. We _____ for her because she never came.
A. mustn’t have waited B. shouldn’t have waited
C. mustn’t wait D. needn’t wait
20. — May I stop here? — No, you _____.
A. mustn’t B. might not C. needn’t D. won’t
21. It’s a fine day. Let’s go fishing, _____.
A. won’t we B. will we C. don’t we D. shall we
22. I didn’t see her in the meeting room this morning. She _____ at the meeting.
A. mustn’t have spoken B. shouldn’t have spoken
C. needn’t have spoken D. couldn’t have spoken
23. — Please don’t make a noise.
— _____. I’ll be as quiet as a mouse.
A. Yes, I won’t B. No, I won’t C. No, I will D. Yes, I will
24. The young man has made so much noise that he _____ not have been allowed to attend the concert.
A. could B. must C. would D. should
25. — Where is John? — He _____ in the library.
A. should be B. must be C. can be D. must have been
26. Since the road is wet this morning, _____ last night.
A. it must rain B. it must be raining
C. it must have rained D. it must have been rain
27. — Will your brother stay home tonight?
— I’m not quite sure. He _____ to the cinema tonight.
A. must go B. can go C. may go D. may be going
28. She’s already two hours late. What ______ to her?
A. can have happened B. may have happened
C. should have happened D. must happen
29. You must be a writer, _____?
A. mustn’t you B. are you C. must you D. aren’t you
30. I got up early that morning, but I _____ so because I had no work to do.
A. mustn’t have done B. didn’t need to do
C. needn’t have done D. can’t have done
31. He _____ have come here yesterday, but he didn’t.
A. could B. should C. ought to D. all the above
32. I missed the last bus, so I _____ go home on foot.
A. must B. have to C. may D. had to
33. He ought to win the first prize, _____ he?
A. oughtn’t B. shouldn’t C. mustn’t D. both A and B
34. Everyone _____ do his best for the modernizations of our country.
A. can B. may C. should D. might
35. Let’s clean our classroom, _____?
A. will you B. don’t we C. shall we D. do you
36. Let us play basketball, ______?
A. will you B. don’t we C. shall we D. do you
37. He asked me for this book many times. Please tell him that he _____ have it tomorrow.
A. must B. may C. shall D. both B and C
38. “Your phone number again? I _____ quite catch it.” “It’s 9568442.”
A. didn’t B. couldn’t C. don’t D. can’t
39. Mother _____ us stories when we were children.
A. was used to tell B. is used to telling C. used to tell D. used to telling
40. She would rather _____ more money on books _____ on clothes.
A. cost … not B. to spare … don’t C. pay … than D. spend … than
2）强化练习题
1) You____ all those clothes! We have a washing machine to do that sort of thing.
A) needn't have washed B) shouldn't have washed
C) must not have washed D) can not have washed
2) John's score on the test is the highest in the class; he____ last night.
A) should study B) should have studied
C) must have studied D) must have to study
3) The room is in a terrible mess; it ____cleaned.
A) can't have been B) shouldn't have been
C) mustn't have been D) wouldn't have been
4) Nobody knows how people first came to these islands. They ____ from South America on rafts.
A) must have sailed B) can sail C) might have sailed D) should have sailed 5) Mary was not in her bedroom yesterday afternoon. She ____ in her classroom.
A) should have been B) must have been C) must be D) should be 6) Bob said he was going to join our club but he didn't. He ____ his mind.
A) can't have changed B) wouldn't have changed
C) must have changed D) shouldn't have changed
7) You____ to town to see the film yesterday. It will be on TV tonight.
A) needn't go B) had better not go C) should not go D) needn't have gone
8) We____ the letter yesterday, but it didn't arrive.
A) must receive B) ought to receive
C) must have received D) ought to have received
9) With all the work on hand, he____ to the cinema last night.
A) mustn't go B) shouldn't have gone C) could not go D) couldn't have gone
10) Eve was late for class again. She ____earlier.
A) should get up B) must get up C) need to get up D) should have got up
11) I am feeling sick. I____ so much chocolate.
A) needn't have eaten B) couldn't have eaten
C) mustn't have eaten D) shouldn't have eaten
12) I didn't send out my application form last week, but I ____.
A) had B) would do C) should have D) might have to
13) Walking alone in the deserted village, John was scared. He thought he____ Tom to go with him.
A) might have asked B) should asked C) must have asked D) should have asked
14) When I got to the cinema, the film had already started; I____ there earlier.
A) ought to get B) ought to have got C) must have got D) must get
15) The road was muddy. It____ last night.
A) must rained B) must have rained C) must be rained D) could have rained
16) She can speak quite fluent English. She____.
A) must been in the U.S.A. for some time
B) must have been in the U.S.A. for some time
C) should have been in the U.S.A. for some time
D) May be in the U.S.A. for some time
17) You should bear in mind that he is not so strong as he____.
A) was used to be B) used to be C) was used to D) use to
18)“We didn't see him at the exhibition yesterday.”“He ___it.”
A) mustn't visit B) can't have visited C) should have gone to see D) may see
19) Mary ____my letter, otherwise she would have replied before now.
A) should have received B) has received
C) couldn't have received D) ought to have received
20) I ____ you a valuable present for your birthday, but I was short of money.
A) would have liked to give B) liked to give
C) have liked to give D) would like to give
21)“Where ____ my umbrella?”“Somebody ____ it away by mistake.”
A) is, must have taken B) is, must take
C) have been, must take D) is, takes
22) What ____ would happen if the director knew you felt that way?
A) will you suppose B) you suppose
C) do you suppose D) you would suppose
23) Two eyes ____see more than one.
A) can B) may C) will D) should
24) ____ you continue in your efforts and achieve new and greater successes.
A) Would B) Will C) May D) Should
25) We ought to help each other in our work, ____?
A) oughtn't we B) should we C) shouldn't we D) ought to we
26) Tom ____ better than to ask * for help.
A) shall know B) shouldn't know C) has known D) should have known
27) You ____ your tooth pulled out before it rot completely.
A) had better got B) had to get better C) had better to get D) had better get
28) When we got to the cinema, the film hasn't started yet, so we ____.
A) needn't hurry B) didn't need hurry
C) needn't to hurry D) needn't have hurried
29) It was really very dangerous; you ____ him seriously.
A) might have injured B) could injure
C) should have injured D) must injure
30) As he had heart attack, he was told that he ____ continue the work.
A) needn't B) may not C) mustn't D) can't
31) An Englishman who ____not speak Italian was once traveling in Italy.
A) must B) could C) may D) might
32) I ____like to make a suggestion.
A) could B) would C) must D) might
33) I know things are hard with you, but you ____try to get over the difficulties.
A) can B) may C) must D) ought
34 I can't find the recorder in the room. It ____ by somebody.
A) may have been taken away B) may leave
C) may take away D) must have taken away
35) He ____the 9:20 train because he didn't leave home till 9:25.
A) can reach B) could catch C) may not catch D) couldn't have caught
3) 单句改错（先判断句子是否正确，正确的句子不需改动。）
1. Ought you smoke so much?
2. If Fred didn’t leave here before five, he mustn’t be home yet.
3. I’m going home. I don’t want to but I must, because my mother asked me not to go out after dark.
4. After I’ve finished my course, I’ll can speak English fluently.
5. I can be seeing the top of the tower in this bedroom.
6. You are not able to play football in the park on Sundays, though you may do so on weekdays.
7. He can’t be working at this hour!
8. Mary Blake ought to not be home by now.
9. His luggage is still here, he must not have left.
10. I used to writing poetry myself when I was his age.
三、能力提升
1. You _____ return the book now. You can keep it till next week if you like.
A. can’t B. mustn’t C. needn’t D. may not
2. Where is my pen? I _____ it.
A. might lose B. would have lost C. should have lost D. must have lost
3. I wish I _____ you yesterday.
A. seen B. did see C. had seen D. were to see
4. I didn’t hear the phone. I _____ asleep.
A. must be B. must have been C. should be D. should have been
5. If my lawyer _____ here last Saturday, he _____ me from going.
A. had been; would have prevented B. had been; would prevent
C. were; would prevent D. were; would have prevented
6. He _____ you more help, even though he was very busy.
A. might have given B. might have C. may have given D. may give
7. If it _____ for the snow, we _____ the mountain yesterday.
A. were not; could have climbed B. were not; could climb
C. had not been; could have climbed D. had not been; could climb
8. Without electricity human life _____ quite difficult today.
A. is B. will be C. would have been D. would be
9. A computer _____ think for itself, it must be told what to do.
A. can’t B. couldn’t C. may not D. might not
10. Jenny _____ have kept her word. I wonder why she changed her mind.
A. must B. should C. need D. would
11. We _____ last night, but we went to the concert instead.
A. must have studied B. might study C. should have studied D. would study
12. — Could I borrow your dictionary?
— Yes, of course you _____.
A. might B. will C. can D. should
13. Tom ought not to _____ me your secret, but he meant no harm.
A. have told B. tell C. be telling D. having told
14. — If he _____, he _____ that food.
— Luckily he was sent to the hospital immediately.
A. was warned; would not take B. had been warned; would not have taken
C. would be warned; had not taken D. would have been warned; had not taken
15. Peter _____ come with us tonight, but he isn’t very sure yet.
A. must B. may C. can D. will
16. I told Sally how to get here, but perhaps I _____ for her.
A. had to write it out B. must have written it out
C. should have written it out D. ought to write it out
17. I didn’t see your sister at the meeting. If she _____, she would have met my brother.
A. has come B. did come C. came D. had come
18. — 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
19. When a pencil is partly in a glass of water, it looks as if it _____.
A. breaks B. has broken C. were broken D. had been broken
20. It’s nearly seven o’clock. Jack _____ be here at any moment.
A. must B. need C. should D. can
21.— There were already five people in the car but they managed to take me as well.
— It _____ a comfortable journey.
A. can’t be B. shouldn’t be C. mustn’t have been D. couldn’t have been
22. Johnny, you _____ play with the knife, you _____ hurt yourself.
A. won’t; can’t B. mustn’t; may C. shouldn’t; must D. can’t; shouldn’t
23. The fire spread through the hotel very quickly but everyone _____ get out.
A. had to B. would C. could D. was able to
24. — When can I come for the photos? I need them tomorrow afternoon.
— They _____ be ready by 12:00.
A. can B. should C. might D. need
25. — I stayed at a hotel while in New York.
— Oh, did you? You _____ with Barbara.
A. could have stayed B. could stay C. would stay D. must have stayed
26. — Will you stay for lunch?
— Sorry, _____. My brother is coming to see me.
A. I mustn’t B. I can’t C. I needn’t D. I won’t
27. — Are you coming to Jeff’s party?
— I’m not sure. I _____ go to the concert instead.
A. must B. would C. should D. might
28. — Write to me when you get home.
— _____.
A. I must B. I should C. I will D. I can
29. I was really anxious about you, you _____ home without a word.
A. mustn’t leave B. shouldn’t have left C. couldn’t have left D. needn’t leave
30. — Is John coming by train?
— He should, but he _____ not. He likes driving his car.
A. must B. can C. need D. may
解答部分
基础训练部分
1——5 ACCCC 6——10 DDBCD 11——15 CCACB 16——20 BACCA
1. had better 2. have gone 3. need not go 4. to have taken
5. mustn’t 6. was able to 7. don’t need 8. should have gone
9. should have 10. will 11. shall not 12. will
13. shall 14. had better 15. Can
强化练习1）选择填空部分答案解析
1. D. must表示推测时不用于否定句；shouldn’t have done sth. 表示“本不应该做某事而实际上做了”；needn’t have done sth. 表示“本来不必做某事而实际上做了”；couldn’t have done sth. 表示“不可能做过某事”。根据题意，选D。
2. A. 情态动词ought 后要接带to的不定式，ought to do 的否定式是ought not to do，所以答案是A。
3. A. must not always be doing sth. 表示“不要老是做谋事”，含有埋怨、指责、反感等感情色彩。
4. D. 题中的A项和B项都指现在情况；couldn’t have gone表示“不可能去过”；shouldn’t have gone表示“本不应该去而实际上去了”。根据题意，选D。
5. D. could have done sth. 表示“本来能够做某事而实际上未能做成”。
6. D. should可用于表示惊奇、感叹、不满等感情色彩的句子，如指过去的动作，则要用should have done sth. Would 和 may通常不带感情色彩。
7. C. 题中的dare是情态动词，后接不带to的不定式，主要用于疑问句、否定句和条件句中。
8. B. must开头的疑问句，否定答语用needn’t或don’t have to。
9. C. would rather通常也视为情态动词（组），后接动词原形，其否定形式为would rather not。
10. D. need作为情态动词，其否定形式为needn’t；作实义动词时，其否定形式为don’t (doesn’t) need to do。
11. D. must用在肯定句中表推测时，语气比could, would等肯定得多。此处“must + 不定式进行式”表“想必正在……”之意。
12. A. would rather … than …，意为“宁愿（做）……而不（做）……”。
13. B. 由句意可知，这是对过去发生的事情不太有把握的推测。
14. D. needn’t have done意为“过去不必做而做了某事”。
15. D. should have done表示“过去应该做而没有做某事”。
16. C. can’t（不能），mustn’t（不准），may not（不可以），均不合题意。
17. D. don’t have to = needn’t
18. D. will用在第二人称的疑问句中，为询问（或征求）对方的意愿或向对方提出请求之意。
19. B. should not have done表示“过去不应该做而做了某事”，含有“后悔”、“责备”、“劝告”，“批评”之意。
20. A. may开头的疑问句，否定答语常用mustn’t。
21. D. 疑问句中shall用于第一、三人称，用来征询对方的意见。
22. D. 推测“她不可能在会上发言”，must表示推测时，不能用于否定句中。
23. B. will在此处表示“意志（向）”。
24. D. should not have done表示“过去不应该做而做了某事”，含有“后悔”、“责备”、“劝告”，“批评”之意。
25. B. must do表示对现在的事实进行推测。
26. C. must have done用于对过去发生的事情进行推测，且较有把握。
27. C. 表示推测时，must比may语气肯定。
28. A. can表推测，只用于否定句和疑问句中。
29. D. must表示推测时，其后的反意问句有两种情况：①对现存状态（现在的事实）进行推测时，反意疑问句中动词用其一般现在形式。②对过去发生的事情进行推测时，若有表过去的时间状语，反意问句用动词的过去式。
30. C. needn’t have done表示“过去不必做而做了某事”，若表示“不必做某事（且实际上未做）”则用“didn’t / don’t / doesn’t need to.”
31. D. A表示“本能够”，B, C表“本应该”。
32. D. have to表示客观上要求做某事，must表示主观上认为必须做某事。
33. D. ought to的反意问句应用oughtn’t或shouldn’t开头。
34. C. should 含“按理应该做……”、“有义务做……”之意。
35. C. Let’s 中的us一般包括对方在内。
36. A. Let us中的us一般不包括对方在内。
37. D. may和shall均可表“允诺”。
38. A. 由句后得知句意为“我开始没听清楚对方的电话号码”，为对过去的事实或发生动作的表述。
39. C. used to do“过去（常）做某事”，be used to doing“习惯于做某事”。
40. D. would rather后接动词原形。Spend … on sth.为常用结构。
强化练习2）答案
1——5 ACACB 6——10 CDDDD 11——15 DCDBB 16——20 BBCCA
21——25 ACACA 26——30 DDDAC 31——35 BBCAD
强化练习3）单句改错答案
1. (No mistake)在否定句和疑问句中，ought后面的to可省。
2. mustn’t — can’t 3. must — have to 4. can — be able to
5. be seeing — see 6. are not able to — cannot 7. (No mistake)
8. to not — not to 9. must — can 10. writing — write
能力提升答案全解
1．C 从原题中You can keep it till next week if you like这一信息句可知，“你不必现在还”。
2．D 从原题中Where is my pen?这一信息句可告诉考生，“笔丢了”，丢的动作是过去发生的。因此用must + have done表示对过去事实的肯定猜测。
3．C 原题中的yesterday这一信息词告诉考生，在wish后的宾语从句中，用过去完成时，表示与过去事实相反的愿望。
4．B 从原题中的I didn’t hear the phone.这一信息可以判断出，用must have done表示过去事实的准确的肯定猜测。
5．A 从原题中last Saturday这一信息词可知，条件句中用表示与过去事实相反的过去完成时，主句用would + have done。
6．A might have + 过去分词，在次是虚拟语气，表示“本来可以给你更多的帮助”，而事实则是帮助较少。
7．C 从原题中的yesterday这一信息词暗示考生，该句应选用与过去事实相反的过去完成时，If it had not been for … “要不是因为……”。
8．D 原题中的Without electricity相当于一个条件句：If there were no electricity,故主句用human life would be quite difficult today.
9．A can可以表示一种客观上的能力，本句can’t，表示“不能，不会”。
10．B 从原题总的“I wonder why she changed her mind”“我不知道为何他改变了主意了。”这句话告诉考生Janny没有守诺言。因此，用should + have done，表示“过去本应该做某事，而实际上没有做”。
11．C 可参看10题。意思是：“昨晚本应该学习，但是却去听音乐会了。”
12．C 原题中的could不是过去时，而表示一种委婉、客气的礼貌用语。因此用could提问时，用can回答。同样用would，might提问，用will和may回答。[注意]①— Would you rather do such a thing? — Yes, I would.
②— Would you like some tea? — Yes, I would.
这两个对话中的would rather，would like是惯用法，故不能用will来回答。因为在这两个句型中，will不能去替换would。
13．A 可参看10、15题。该句意思是：“汤姆本来不该告诉我你的秘密，但他没有伤害你的意思。”ought not to have done = shouldn’t have done
14．B 从答语中的Luckily he was sent to the hospital immediately这一信息句可提示考生，条件句应填表示与过去事实相反的时态。
15．B 从原题中的but he isn’t very sure yet这一信息句可暗示考生，Peter当晚来的可能性不大。A是“准来，肯定来”，D是“将要来”。
16．C 可参看10、11、13题。“本应该”而事实上没有……
17．D 从原题中I didn’t see your sister at the meeting和后文she would have met my brother这两个信息句可知，if条件句中应填与过去事实相反的过去完成时。可参看6、7、14题。
18．A 你不必告诉他。因为I’ve told him already这一信息句已暗示考生了。
19．C 当as if引导虚拟语气的句子是，如果主句与从句中的谓语词所表达的动作同时发生时，as if后接一般过去时。例如：He walked as if he were lame.如果从句中的谓语动作发生个在主句谓语动作之前，则用过去完成时。例如：He talked as if he had known the secret.不论主句中的谓语是现在时还是过去时。
20．C 只要考生抓住nearly一词和后文at any moment（随时的意思）这两个信息词语，就能很快选出C项，表示逻辑推测，意思是“快七点钟了，杰克一会儿就该到了。”
21．D 根据句意，是对过去情况的推测。“当时决不可能是一次舒服的乘车。”must表示对过去的推测只能用于肯定句。
22．B mustn’t表示“禁止”；may表示“有可能”。句子的意思是：“你不可以玩刀，可能会伤你自己。”
23．D 该题在考考生could与was able to之间的区别。Was able to表示在困难的情况下，经过一番周折而“能……”，并且成功地做了。
24．B 该题考查情态动词should表推测的用法。Can和might都可以表示可能性，用might则语气更加不肯定。Need表示“需要”、“必需”。Should可以表示推测，结合实际，合乎逻辑，意为“应当”、“该”。根据第一个说话者说的I need them tomorrow afternoon的语境，可以确定正确答案为B。
25．A 该题在考查“情态动词+不定式的完成式”的用法，从会话的语境看，空白处应填“could + have +过去分词”表示过去本来能做到的事而事实上没有做到。
26．B 该题考查表示请求的英语口语，用will来向第二人称提问的疑问结构，是表达一种意愿和请求，是以疑问的形式来表达较为婉转的祈使语气，意思是“请你……，好吗？”，对于这种问句的肯定答语可用Sure! Certainly! Yes, of course. I’d be glad to等；否定回答通常是I’m sorry, I can’t. No, I’m afraid I can’t. I’m sorry, but … I ‘d like to, but …等。
27．D might表示“可能性”。
28．C 意思是“我会的”。对祈使句的肯定回答。
29．B shouldn’t have done为本来不该做某事，而事实上做了。
30．D 用may not可表示“可能不”。而can not则表示断然的否定推测“不可能”。A，C意思不符。