D. Underline the correct item. 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.

21. You must pay your rent. That's the rule. (Вы должны платить за аренду. Это правило.) 22. You mustn't eat in the classroom. It's forbidden. (Вы не должны есть в классе. Это запрещено.) 23. You can't have any pets in this house. It's not allowed. (Вам нельзя держать никаких домашних животных в этом доме. Это не разрешено.)