What's activity is this?
You must put litter in the garbage can.
What's activity is this?
You must wash your hands.
What's activity is this?
You must be quiet.
What's activity is this?
You mustn't walk your dog here.
What's activity is this?
You mustn't walk on the grass.
What's activity is this?
You mustn't take photos here.
What's activity is this?
You mustn't eat here.
What's activity is this?
You mustn't ride your bike here.
