Answer:
In a tunnel of darkness lies a beast of iron. I can only attack when pulled back. What am I?
I am the place to turn to when nature calls. What am I?
I have cities with no people forests with no trees and oceans with no water.
I run through hills. I veer around mountains. I leap over rivers and crawl through the forests. Step out your door to find me. What am I?
I regularly change shape yet remain a sphere. I am always there but not often seen. What am I?
I flow from the Homerβs mouth when he sees doughnuts.