Question

Must/mustn't,can/can't(i,you,he,she,it,we,they) you,must de quiet after 10.30. You mustn't play loud music after 10.30. You can put some poster on the walns. You can't make coffee in your room

Answer 1

1-you must study all day long if you want to pass the exam
2- you mustn't eat ice cream when you have a sore throat
3-you can play computer games.
4- you can't help her,she doesn't want your help