英语笑话:一个有效的方法Useful Way

　 A Useful Way

　　　　　　　　　Father: Jack, why do you drink so much water?
　　　　　　　　　Jack: I have just had an apple, Dad.
　　　　　　　　　Father: What's that got to do with it?
　　　　　　　　　Jack: I forgot to wash the apple.