Answer:
I am the thing that is used to make your weight. What am I?
I help engines spin and pants stay up.
I shrink smaller every time I take a bath.
I am always hungry, I must always be fed. The finger I lick will soon turn red. What am I?
A spirited jig I dance bright, banishing all but darkest night. Air can't kill me but water can. Share me, I won't get less unless wind ruins me. What am I?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.