Answer:
What has keys but no locks a space but no room and you can enter but can't go in?
You use a knife to slice my head but you weep beside me when I am dead
Travel a mile and I will change, travel a million and I will end as I started. What am I?
What is so delicate that saying its name breaks it?
You can see me in water, but I never get wet. What am I?
What made Cyclops quit teaching?