Say what you must or mustn't do.
1)Walk on the grass in the park
2)Help people
3)Speak on the mobile in class
4)Take photos in the museum
5)Look after the pets will
6)Go to bed very late
7)Talk with friends in the lessons
8)Shout at people

1. We must not walk on the grass in the parks
2. We must help people
3. We must not speak on the mobile in class
4. We must not take photos in the museum
5. We must look after the pets 
6. We must not go to bed very late
7. We must not talk with friends in the lessons
8. We must not shout at people