Skinny Dipping 裸泳 来自幽默学英语网http://www.linkstom.cn/humor/

One day Jimmy went down to the pond for a dip, but before he could dive in he spied his teacher, Mrs. Smith, emerging from nude bathing. When Mrs. Smith saw Jimmy, she grabbed the nearest object - which happened to be an old wooden box - and held it in front of her.
"Young man, I know what you're thinking," she said.
"And I know what you're thinking," replied Jimmy. "You're thinking that box has a bottom on it!"

Jimmy去池塘游泳，他扎猛子前刚好看到了他的老师，Smith小姐，从裸泳中冒出头来。当Smith小姐看到Jimmy时，她赶紧抓过最近的一个物体---那碰巧是一个旧的木头盒子，挡在自己前面，说：“年轻人，我知道你在想什么！”“我也知道你在想什么，”Jimmy回答，“你一定以为这个盒子是有底的！”