Question

用must, mustn't, can, can't填空。

1. Don't open your present now! In China you _____  wait and open it later.
2. —Can I do cleaning at Spring Festival?
    —No, you_____  .  
    —It's bad luck.
3. In America you _____  open your present immediately.
You don't have to wait!
4. In Britain you _____  ride your bicycle on the pavement _____. It's too dangerous.
5. In Britain, you _____ be 18 if you want to drive a car.

Answer 1

1. must  2. can't  3. can  4. mustn't  5. must