Помогите, даю 40 балловChoose the correct item1) You "mustn039;t/don039;t have to"

Помогите, даю 40 баллов
Choose the correct item
1) You "mustn't/don't have to" use your phone in class.
2) Look at the clouds - it "must/might" rain later.
3) You "must/have" to take off your shoes before entering a Japanese home.
4) These clothes are old. I "might/need" to buy new ones.
5) I'd love another piece of cake , but i "mustn't/ don't need to".