Good Riddles

Question: Drop me and the world will shatter,
and you can always find me where you empty your bladder.

What am I?

Question: Different lights make me strange,
for each one my size will change.

What am I?

Question: I'm the eyelid to your life and hide you when you're inside.
You can draw me and you can pull me, but you must leave to see my good side.

What am I?

Question: There was once three trees. The first tree did whatever the third tree did, and the third tree did what ever the second one does. What happens if tree number two gets cut down?

Question: What goes around comes around?