Answer:
I have cities with no people forests with no trees and oceans with no water.
I am used when you jump off a bridge for fun.
I may be made of metal bone or wood and have many teeth. My bite hurts no one and the ladies love me.
The more holes you cover the lower I go.
I go up and down at the same time. Up towards to sky and down towards the ground. What am I?
When is it bad luck to see a black cat?