They __________ walk on the grass.
mustn't
It is raining. You __________ take your umbrella.
must
You __________ be friendly to everybody.
must
This is a secret. You __________ tell anybody.
mustn't
You __________ light fires in the forest.
mustn't
We __________ hurry or we will miss the bus.
must
The baby is sleeping. You __________ shout.
mustn't
She is ill, so she __________ see the doctor.
must
You __________ throw litter on the stairs.
mustn't
You __________ make noise in the library.
mustn't