Answer:
I plow and plow but never sow.
Many people own a copy of me. Without me the world would fall.
I'm written with two letters, said with one and seen with two. What am I?
What word becomes shorter when you add two letters to it?
They come out at night without being called. They are lost in the day without being stolen. What are they?
For our ambrosia we were blessed, By Jupiter, with a sting of death. Though our might, to some is jest, We have quelled the dragon's breath. Who are we?