Answer:
I tremble at each breath of air, and yet can heaviest burdens bear.
Turn us on our backs and open up our stomachs you will be the wisest of men though at start a lummox.
Whoever makes it, tells it not. Whoever takes it, knows it not. Whoever knows it, wants it not. What is it?
What has three feet but no arms or legs?
There is a creature of God whose body is hardΝΎ it does not wish to eat unless you strike its head.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.