Bai 3

1Must

2mustn’t

3 mustn’t

4 must

5 must

6 must

7 mustn’t

8 mustn’t

9 mustn’t

Bai 4

1 you should be on time

3 you should  bring your business

5 you should say…being treated

7 you should make loud gulding noises when drinking

2 you shouldn’tpass food one pair of chopsticker to the other

4 you shouldn’t bring outside food into restaurants

6 you shouldn’t  use the phone in trains and elevators

8 you shouldn’t drink or eat while walking

10 you shouldn’t use your chopstivks to point at somebody