Three things you have to do every day
Three things you can't do in a park
Three things you must do before you get on an airplane
Three things you don't have to do when you are on holiday
Three things you can't do in a library
Three things you will do in a cinema
Three things you should do if you want to lose weight
Three things you mustn't do when you are driving a car
Three things you may/might do later
Three things you mustn't do in a restaurant
Three places you can't go into without paying
Three things you have to do after class