英語幽默:4個英語謎語

Q: What starts with E, ends with E and only has one letter?
A: An envelope.

Q: If you drop a white hat into the Red Sea, what does it become?
A: Wet.

Q: What do you call a boomerang that won't come back?
A: A stick.

Q: What is white when it's dirty and black when it's clean?
A: A blackboard.