Answer:
What hangs in the sky by day but at night goes away?
What has one head, one foot, and four legs?
Once you know it exists, it no longer exists. What is it?
What has only two words, but thousands of letters?
You walk into a room with a match, a kerosene lamp and a fireplace. Which do you light first?
Two little holes in the side of a hill. Just as you come to the cherry-red mill.