Underline the correct item: e.g. You must/mustn't talk during the test. It's against the rules. 21 You must/can't pay your rent. That's the rule. 22 You must/mustn't eat in the classroom. It's forbidden. 23 You must/can't have any pets in this house. It's not allowed. 24 You must/mustn't go to the doctor. You look very ill. 25 You must/can't go to school. That's the law.