3 . When it comes to teachers’ praise or criticism, we ________ it seriously.
当谈到老师的表扬或批评时，我们最好认真对待。

4 . 选词填空。
1. He ________(must/might) get here in time ,but I can’t be sure.
2. He ________(can’t/mustn’t) have missed the train; he arrrived at the train station two hours early.
3. That must be a mistake. No, it ________(can’t/mustn’t) be a mistake.
4. Paul did a great job in the speech contest. He ________(must/can) have practised many times last week.
5. He ________(may/must) be at his office now, but you’d better make a phone to make sure.
6. Look, someone’s in the room. Who ________(can/must) it be ?
7. It ________(must have /may have) rained last night, for the ground is still wet.
8. I don’t know where she is, she ________(may/must) be in Wuhan.
9. With drones’ ability to see ahead, they ________(could/should ) signal any problem, so that fast -moving trains would be able to react in time.
10. I ________(needn’t/can’t) have bought so much wine -only two people came.

5 . I asked in the bookshop about Will Dutton’s latest book, but all they           tell me was that it would come out before the end of the year.

A．might

B．must

C．could

D．should

6 . 我没有指出他的错误，以便他可以不在他的学生面前丢脸。
I didn’t point out his mistake so that ________in front of his students.

9 . 从行为心理学分析，他奇怪的行为可能源于他最近的压力。(account)
From the perspective of behavioral psychology, ________________.

10 . Handshaking ________ have started as an ancient custom to demonstrate to a stranger that you had no weapon in your hand. (用适当的词填空)