Ｊｏｋｅｓ　ａｎｄ　Ｈｕｍｏｒ

姜经志编译

How Much Is Four Minus Four?

One day, the teacher asked Sam, "How much is four minus four?"Sam was tongue-tied(张口结舌的).The teacher got angry and said,What a fool.You see, if I put four coins in your pock-et, but there is a hole in your pocket and all of them leak out (泄露). Now what is left in your pocket.""The hole, " replied Sam.