Answer:
If I drink I die. If I eat I am fine. What am I?
I cannot be felt, seen or touched. Yet I can be found in everybody. My existence is always in debate, yet I have my own style of music. What am I?
I am filled with garb the price is free. Just return what you don't need.
I am taken from a mine and shut in a wooden case from which I am never released. Yet I am used by almost everybody. What am I?
You use me from your head to your toes. The more I work, the thinner I grow. What am I?
No matter how little or how much you use me, you change me every month.