Answer:
Many people own a copy of me. Without me the world would fall.
In a tunnel of darkness lies a beast or iron. It can only attack when pulled back. What is it?
I am a shimmering field that reaches far. Yet I have no tracks and am crossed without paths. What am I?
What's the capital of France?
I am a king who's good at measuring stuff. What am I?
What made Cyclops quit teaching?