1.They must do morning exercise.
2I must buy a cake to day.
3 My school starts at 8.30. I have to get up at 7.
4 You must wear a uniform at school.
5 You mustn't speak loudly in the cinema.
6 Tomorrow is Sunday. i don't have to wash up.
7 You should go there.
8 You should be more carefull.
9 I think Mary should join.
10 Sam, you must look after your little brothe.