bài tập must vs mustn't

You _______ let your dog play in the fountain.

You _______ put litter in the garbage can.

You _______ walk on the grass.

You _______ pick the flowers.

You _______ walk on the path.

You ______ climb the trees in the park.

You ______ do your homework. Then you can play outside.

You _____ leave any litter in the library.

You ______ be quiet and sit nicely in the classroom.

You ______ walk your dog in the museum.