5. Choose the correct word. 1 You must/needn't/can't eat in the classroom. It's not allowed! 2 Students can't/have to/don't have to take the rubbish out. The cleaners will do it. 3 You needn't/mustn't/can't enter the building after 10 o'clock. The entrance is closed.

Решение:

1. You mustn't eat in the classroom. It's not allowed! (Запрет).
2. Students don't have to take the rubbish out. The cleaners will do it. (Отсутствие необходимости).
3. You can't enter the building after 10 o'clock. The entrance is closed. (Невозможность, запрет).

Ответ: mustn't; don't have to; can't.