Сomplete the sentences with must or mustn't.
1)You ____ do an allready test before you dye your hair.
2)You____stay in the sun for a long time.It's bad for your skin.
3)You____ride your skatebord without a helmet.
4)You____wear that skirt at school again. It's too short and it's too tight.
5)You____put on a coat.It's very cold outside.