Answer:
I come out of the earth, I am sold in the market. The one who buys me cuts my tail, takes off my suit of silk, and weeps beside me when I am dead. What am I?
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
I am two-faced but bear only one. I have no legs but travel widely. Men spill much blood over me. Kings leave their imprint on me. What am I?
I am owned by the poor, the rich do not need me. If you eat me, you will die! What am I?
What can fill a room but takes up no space?
No matter how little or how much you use me, you change me every month.