1 . He ________ have finished writing the paper. He hadn’t written a single word when I left him fifty minutes ago. (用适当的词填空)

2 . She ________ (participate) in the activity, for she was doing paperwork in the office then. （用适当的词填空）

3 . It’s said that they have swum to the island from the continent, but they ________ (不可能做到) because the ocean in between is too wide. (do) (根据汉语提示完成句子)

4 . I didn’t see Fred in the library this morning. He_____have borrowed that book.

A．mustn’t

B．shouldn’t

C．couldn’t

D．needn’t

5 . But for his timely help, we ______ our task in such a short time.

A．wouldn’t finish	B．haven’t finished
C．couldn’t have finished	D．can’t have finished

6 . She ________have participated in the activity, for she was doing paperwork in the office then. (用适当的词填空)

7 . — Excuse me, where is George?
— George ________ too far. His coffee is still warm.

A．must have gone	B．might have gone
C．can’t have gone	D．needn’t have gone

8 . George ______ too far. His tea is still warm.

A．should have gone

B．can’t have gone

C．might have gone

D．needn’t have gone

9 . —It’s really tiring for me to stand in the queue for three hours to get the G-train ticket.
—You _______. You could have got one online.

A．mustn’t have

B．shouldn’t have

C．can’t have

D．needn’t have