Answer:
What is born on the ground but floats to the sky, to be returned back again from the clouds up high?
It is in every mountain, it's not in any hill, it's not in all the world, and yet it's in the mill.
I'm the son of water but when I return to water I die. Who am I?
What is something you can hold without ever touching?
What’s full of holes but still holds water?
What is yours but only used by others?