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).

3 . 选词填空

can, could, may, might, must（包含其否定形式）

1. Helen ________ go on a trip with us, but she isn’t quite sure.
2. My sister met him at the theatre last night, so he ________ have attended your lecture.
3. —I am sure I saw Brian in the park this morning.
—You ________ be imagining things. He left for America last night.
4. —Is John coming by bus?
—Not sure. He should, but he ________. He likes riding his bike.
5. —Isn’t that your teacher over there?
—No, it ________ be him. I'm sure he doesn’t wear glasses.
6. I saw him just now, so he ________ have gone abroad.
7. We ________ have faced the difficulty together, but why didn’t you tell me?
8. —What has happened to George? He hasn’t turned up so far.
—I don’t know. He ________ have got lost in the woods.
9. —She looks very happy. She ________ have passed the exam.
—I guess so. It’s not difficult after all.
10. For example, you ________ want to be a pilot but ________ become one because your eyesight is not good enough.