Вживання must, mustn't

You ... eat in your classroom.

You ... put litter in the bin.

You ... be quiet in class.

We ... do our homework.

You ... talk in class.

You ... turn off your mobile phone at school.

You ... walk on the grass.

You ... run at home.

You ... wash your hands.

You ... walk on the path in the park.

You ...... walk on the grass in the park