be quiet
You must be quiet in the museum.
touch the crocodiles
You mustn't touch the crocodiles in the zoo.
pay before you leave
You must pay before you leave the supermarket.
wear slippers
You must wear slippers in the swimming pool.
run on the stairs
You mustn't run on the stairs at the school.
wash hands
You must wash hands in the hospital.
throw away your rubbish
You mustn't throw away your rubbish in the park.
eat
You mustn't eat in the library.
return your books on time
You must return your books on time to the library.
feed the animals
You mustn't feed the animals in the pet shop.
buy a ticket before you get on the train
You must buy a ticket before you get on the train at the train station.
tidy your desk
You must tidy your desk in the school.