Complete the sentences with must or mustn't. you brush your teeth three times a day. you forget to do your homework regularly. you be nice to your classmates. you wear warm cothes when it is cold outside. you chew gum in class. you study hard if you want to pass your exams. you fight with your classmates. you play football in the classroom. you listen to your teacher very carefully. you forget your best friend's birthday. you be rude to your grandparents. you go to the dentist's twice a year. you stay in bed when you are ill. you feed zoo animals. you do your online exercises. встав те и не писать делай сам и т.п.
2. mustn't forget
3. must be nice
4. must wear
5. mustn't chew
6. must study
7. mustn't fight
8. mustn't play
9. must listen
10. mustn't forget
11. mustn't be rude
12. must go
13. must stay
14. mustn't feed
15. must do