注意:could用来表示请求时,是一种委婉的说法,回答时不可用过去式could 进行回答。而要用原形can --Could you tell me the way to the post office , Please? --Yes, I can. 4.常用于疑问句或否定句,表示惊异、怀疑或不相信的态度。 Can hard work change a person that much? ( How can you be so careless.) 练习 从A、B、C、D四个选项中,选出可以填入空白处的最佳选项。 1. Mike, you ______ play with fire. You______ burn yourself. A. won’t; can’t B. mustn’t; may C. don’t have to; must D. have got to; shouldn’t 2. You ______ see the doctor, Joe. You don’t look very well. A. must B. shall C. may D. can 3. —Must I clean the window now? —No, you ______. A. mustn’t B. needn’t C. can’t D. may not 4. Jack’s ill, so they ______ change their plans. A. must B. should C. have got to D. ought to 5. Harry has been reading all day —he ______ be tired. A. should B. has got to C. has to D. must 6. –Lucy doesn’t mind lending you her dictionary. -- She _____. I’ve already borrowed one. A. can’t B. mustn’t C. needn’t D. shouldn’t 7. He paid for a seat, when he ______ have entered free. A. could B. would C. must D. need 8. John, look at the time. _____ you play the piano at such a late hour? A. Must B. Can C. May D. Need 9. I often see lights in that empty house. Do you think I ____ report it to the police? A. should B. may C. will D. can 10. –Isn’t that Ann’s husband over there? -- No, it _____ be him—I’m sure he doesn’t wear glasses. A. can’t B. must not C. won’t D. may not 11. Children under 12 years of age in that country ____ be under supervision when in a public library. A. must B. may C. can D. need 12. I _____ put Tracy a visit, I’m not sure whether I will have time this Sunday. A. should B. might C. would D. could 13. –Who is the girl standing over there? --Well, if you ____ know, her name is Mabel. A. may B. can C. must D. shall 14. –Tom graduated from college at a very young age. --Oh, he ____ have been a very smart boy then. A. could B. should C. might D. must 15. How _____ you say that you really understand the whole story if you have covered only part of the article? A. can B. must C. need D. may 16. My English-Chinese dictionary has disappeared. Who _____ have taken it? A. should B. must C. must D. would 17. It has been announced that candidates _____ remain in their seats until all the papers have been collected. (责任编辑:admin) |