Answer:
What five-letter word becomes shorter when you add two more letters?
Which button does not function when being pressed?
Who works when he plays and plays when he works?
Who is he that runs without a leg. And his house on his back?
What is round as a dishpan, deep as a tub, and still the oceans couldn't fill it up?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.