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.

　　爸爸：杰克，你干嘛喝这么多水呀?

　　杰克：我刚才吃了个苹果，爸爸。

　　爸爸：可是这跟喝水有什么关系呢?

　　杰克：我忘了洗苹果呀。