Помогите а то не знаю тему пропустила

1) I mustn't go to school on Sundays.
2) We mustn't make noise. My little sister is asleep.
3) I mustn't spend much money.
4) I don't have to do this exercise in writing.
5) He mustn't forget to mail this letter tomorrow.
6) You don't have to come to the party.
7) You don't have to eat it if you don't like it.
8) They don't have to study music this year.