Pick up litter and th-
e world will glitter

On the wall of a science room (Pigeons) there is a display of posters advising people not to leave waste upon the ground, and move it in a binwardly direction. Examples of these are the above, "Pick up litter, and your reward will be a pint of bitter", "Recycle your waste, and your live to 108",. "Don't be dim, recycle your tins", etc.