Other brain teasers:

1, Mrs. Wang talks all day, but she talks the least in a month. What month is it?

Answer: February.

2. What water can't be drunk?

Answer: salary.

Why can't the plane hit the stars no matter how high it flies?

Answer: The stars will twinkle.

4. Why do silkworm babies have money?

Answer: Because silkworms can cocoon (thrifty).

5. Why do geese fly to the south for the winter?

Answer: geese can't go south, so they fly.