1 . —Would you like to go swimming with me this afternoon?
—I’d love to. But I’ m afraid I________. I have too much work to do.

A．can’t

B．mustn’t

C．needn’t

D．may not

2 . 开始打雷的时候，他们可能落在了后面，还走错了路。(might, fall, take)
When the thunder started, ________ and _____.

3 . —I can’t give up smoking, doctor.
—For your health, I’m afraid you     .

A．may

B．can

C．have to

4 . — Where will you start your work after graduation?
— Mmm, it’s not been decided yet. I____ continue my study for a higher degree.

A．need	B．must
C．would	D．may

5 . Although this ____ sound like a simple task, great care is needed.

A．must

B．may

C．shall

D．should