http://www.funology.com/riddles/

Q: What has a foot but no legs?
A: A snail

Q: Poor people have it. Rich people need it. If you eat it you die. What is it?
A: Nothing

Q: What comes down but never goes up?
A: Rain

Q: I’m tall when I’m young and I’m short when I’m old. What am I?
A: A candle