Use must or mustn't.
1) You… go out. It is raining.
2) Your room is messy. You... do your room and wash the floor.
3) Bob has a high temperature. He... go to school.
4) Its eleven o'clock Betty… eat much chocolate.
5) You… play in the street. It's dangerous.
2)must
3)mustn’t
4)mustn’t
5)mustn’t