complete the sentences with must or musn't 

we___________step on the grass in the yard.

everyone_______wear a life vest when boating.

student _________ pick flowers in the school garden.

we________leave now or we'll miss the plane.

your hands are dirty. You ______ touch anything.

you______take photos in the gallery.

we_________book the tickets before it's too late.

you______use a mobile phone when the palne is taking off.

giups em vs em ddg caanf =__))