1 . 只有你努力学习，才能取得进步。
_____________________________ you work hard, _______________________ make progress.

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

A．may

B．can

C．have to

3 . Reading a large number of books ________ make us wiser.

A．should

B．can

C．need

D．must

4 . 在空白处填适当的情态动词。
1. “Look at these tracks. It ______ be a wolf.” “Don’t be so sure. I think it ______ be a fox.”
2. I didn’t see her in the meeting room this morning. She ______ have spoken at the meeting.
3. It’s a very kind offer, but I really ______ accept it.
4. The boss said to the secretary, “If you work well, you ______ have a rise.”

5 . —Where did you get this book?
—I picked it up from a second-hand bookshop if you ______ know.

A．must

B．will

C．can

D．shall