Answer:
I start new then become old. Start clean but become dirty. I usually start big then become little. What am I?
Whoever made me doesn't want me. Whoever bought me doesn't need me. Whoever uses me doesn't know me. What am I?
I have cities without people forests without trees and oceans without water. What am I?
What can you catch but not throw?
I help engines spin and pants stay up.
A word of five letters, Upside down is the same, A shark does this, But itβs not to blame. What is the word?