3. Say what you must or mustn't do.

Решение:

• 1. You must walk on the grass in the park. (Это общее правило поведения в парке.)
• 2. You must help people. (Это моральный долг.)
• 3. You mustn't speak on the mobile in class. (Это правило поведения на уроке.)
• 4. You must take photos in the museum. (Это разрешено, если нет специальных запретов.)
• 5. You must look after the pets well. (Это обязанность, если у вас есть питомцы.)
• 6. You mustn't go to bed very late. (Это рекомендация для здоровья.)
• 7. You mustn't talk with friends in the lesson. (Это правило поведения на уроке.)
• 8. You mustn't shout at people. (Это правило вежливости и уважения.)

Ответ:

• 1. You must walk on the grass in the park.
• 2. You must help people.
• 3. You mustn't speak on the mobile in class.
• 4. You must take photos in the museum.
• 5. You must look after the pets well.
• 6. You mustn't go to bed very late.
• 7. You mustn't talk with friends in the lesson.
• 8. You mustn't shout at people.