Answer:
It is not your enemy, yet we still beat it. What is it?
Why is a river rich?
What did the boy coffee say to the girl coffee?
What's behind every strong, beautiful woman?
Has 88 keys, but not one of them will open a door.
Who makes it, has no need of it. Who buys it, has no use for it. Who uses it, can't see it. What is it?