Good Riddles

 
Riddle #2 (easy)

Question: What occurs once in a minute, twice in a moment and never in one thousand years?

Riddle #571 (medium)

Question: What is something that you always have with you but you always leave behind?

Riddle #38 (easy)

Question: The person who buys me doesn't need me, the person who makes me doesn't want me, and the person who uses me can't appreciate me.

What am I?

Riddle #210 (medium)

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: Under pressure is the only way I work,
and by myself is the only way I'm hurt.

What am I?