You can sit down and have a rest改为祈使句

You can sit down and have a rest改为祈使句
You mustn't sleep in class.
You may read some books.
You moustn't be late for school.
You'd better not litter here.
Can I use your rubber?
Will you please not play with my litter dog?
You must clean the windows.
You can't put your bike here.
You shouldn't ride a bike in the park.