Answer:
I am the greatest teacher out of them all, but alas in the end I kill my pupils.
Two bodies have I, though both joined in one. The more still I stand, the quicker I run.
My prefix is food. My suffix is rude. My infix comes in rounds. I keep you off the ground. What Am I?
I do not breathe, but I run and jump. I do not eat, but I swim and stretch. I do not drink, but I sleep and stand. I do not think, but I grow and play. I do not see, but you see me everyday.
I sleep by day, I fly by night. I have no feathers to aid my flight.
I have a face but no eyes hands but no arms.