What Am I Riddles

Question:

The dirtier I am, the whiter I get,
Leave a mark on me when you stand, I'll leave a mark on you when you sit.

What am I?

Question: Shake me and I'll do what you want,
but first you have to pull me from the ground.
I'm on the tip of your tongue and over your shoulder.

What am I?

Question: What can you see but not hear?

Question: A thousand wheels, but move I do not.
Call me what I am, call me a lot.

What am I?

Question: The more of me you have, the longer your life.
The more of me you have, the less you have left.

What am I?