1 . 选词填空
1. He ____________(must/might) get here in time,   but I can’t be sure.
2. —How long ____________(may/must) I keep this book?
—You may keep it for two weeks.
3. He ____________ (can’t/mustn’t) have missed the train;   he arrived at the train station two hours early.
4. John, look at the time. ____________ (Must/Can) you play the piano at such a late hour?
5. She ____________(might/must) have achieved greater progress,   if you had given her more chances.
6. —That must be a mistake.
—No, it ____________ (can’t/mustn’t) be a mistake.
7. Paul did a great job in the speech contest. He ____________(must/can)have practised many times last week.
8. It is usually warm in my hometown in March, but it ____________(may/can)be rather cold sometimes.
9. I can make a lantern now,   but I ____________(can’t/couldn’t)when I was young.
10. —Can we go out and play football now?   
—No,   you ____________(can’t/mightn’t).

2 . 汤姆昨晚一定熬夜到很晚。他是那么困以至于刚才我们在一起唱歌的时候他睡着了。
Tom________ last night. He was________ he fell asleep when we sang a song together just now. (must)

5 . Sam was sure that the wallet ________ by one of the villagers, but it was not returned to him. （根据句意填空）