选用can, could, may, must, shall, should, will, would, can’t, mustn’t, needn’t或have to
填空:
1. There is air around us, thought we ________ see it.
2. Your mother is getting better and better. You _______ worry about her.
3. You _______ play football in the busy street.
4. “_______ it be true ?.” “Yes. It _______ be true indeed.”
5. Tom _______ come to the party tonight, but I’m not sure.
