6. Read, chose and write.

Решение:

• 1. You must go to bed at 10 o'clock. (Предписание).
• 2. She mustn't visit her grandma on Sunday. (Запрет).
• 3. You must help your mother. (Предписание).
• 4. They mustn't talk in class. (Запрет).

Ответ: must, mustn't, must, mustn't