Answer:
What invention lets you look right through a wall?
I must be broken before you can use me.
I have two bodies joined together as one. When standing still I run and run.
To cross the water, I'm the way. For water I'm above, I touch it not and truth to say, I neither swim nor move. What am I?
I don't live within a house nor do I live without. Most will use me when they come in and again when they go out.
What made Cyclops quit teaching?