Read and underline. Then…

1 A: You must/mustn't put your hand up to ask a question.B: OK, Miss.2 A: What's the matter.Officer? B: You must/mustn't park your car here.3. A: You must/mustn't do any sports for two weeks.B: OK, thank you, doctor.4 A: You must/mustn't buy a ticket before you get on the bus.B: Really? Where do I get one from?