must, can, may+動詞的進行式，表示對進行中的事進行推測。例如：

　　1)They must be waiting anxiously now. 他們此刻一定在焦急地等待著。

　　2)Can they be working in the field now? 他們現在可能在地里勞動嗎?

　　八 He must be tired now, ___________?

　　1) He must have been tired last night after a day’s work, ____________?

　　2) He must have been to Hong Kong,___________?

　　keys: 1. isn’t he 2. wasn’t he 3. hasn’t he

　　Practice:

　　1. Sorry, I’m late. I ____________ have turned off the alarm clock and gone to sleep again.

　　A. might B. should C. can D. will

　　2. --- He didn’t pass his English exam.

　　--- So he ________ a good time during the Spring outing yesterday.

　　A. can’t have B. shouldn’t have C. mustn’t have had D. couldn’t have had

　　3. It’s nearly seven o’clock. Jack ________ be here at any moment.

　　A. must B. need C. should D. can

　　4. You can’t imagine that a well-behaved gentleman _______ be so rude to a lady.

　　A. might B. need C. should D. would

　　5. The boy must be in the classroom, _______ he?

　　A. mustn’t B. doesn’t C. hasn’t D. isn’t

　　6. --- Could I borrow your dictionary?

　　--- Yes, of course you ________.

　　A. might B. will C. can D. could

　　7. We wonder why Jim Green ______ say such things.

　　A. dared not to B. doesn’t dare to C. dares not to D. not dares

　　8. I talked a long time, and in the end I _____ make him believe me.

　　A. could B. was able to C. may D. might

　　Keys: ADCC(should表驚訝) DCBB