1 . — Tom graduated from college at a very young age.
— Oh, he ________ have been a very smart boy then. （用适当的词填空）

2 . My wallet is nowhere to be found. I must ___________ (drop) it when I was on the bus.

3 . Mr. White has just bought a new car. His boss must ___________(increase) his salary.

4 . —I phoned you last night, but...
—I didn't hear the phone. I_________asleep.

A．should be	B．should have been
C．must be	D．must have been

5 . My key isn’t in my backpack. Where on earth________ I have put it?

A．can

B．would

C．should

D．must

6 . Mary’s bedroom is so tidy. She ________ have cleaned it last night.

A．can

B．need

C．must

D．should

7 . Hannah一定是在承诺不告诉他人之后将我的成绩告诉了我的同学们。（must）

8 . He knows so much about the problem. He must have ________ (参考) to lots of books.

9 . We________ have watched that thriller in the cinema, because we may have horrible dreams at night.

A．needn’t

B．shouldn’t

C．mustn’t

D．couldn’t

10 . Green先生一定因为昨天在会上鲁莽的行为被处罚了。(must have done)
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