You ______ stop!
must
You MUST step on the grass. YES or NO?
No, you MUSN'T.
You ________ have brakes to stop the bike.
must
You ________ run near the swimming pool.
mustn't
You _________ stop and wait!
must
You MUSN'T wear a helmet when you go cycling. YES or NO?
No, you MUST.
You must eat or drink inside the library. YES or NO?
No, you MUSN'T.
You musn't _________.
take photos.
You ________ give your seat to older people.
must
You MUST play football in the classroom.
No, you MUSN'T.