What Am I Riddles

Question: What demands an answer, but asks no question?

Question: I build bridges of silver and crowns of gold.Who am I?

Question: Filled with garb,
the price is free.
Just return what you don't need.

What am I?

Question: The more you work, the more I'll eat.You keep me full, I'll keep you neat. What am I?

Question: I give advice to others,
yet I know nothing myself.
I am a hitchhiker destined to stay still.