The man in the prison asked a new comer why he was sent there. The new comer answered: I am out of luck, I think. A few days ago I was walking in the street when I saw a piece of dirty rope. I thought nobody wanted it and so I picked it up and took it home. 

　　But it is not against the law to pick up a piece of rope and take home! 

　　I told you I had bad luck, didn't I? the man sighed, The trouble is that I didn't notice there was an ox at the other end of that rope. 

　　绳子还是公牛？ 

　　在监狱里，一个人问新来的犯人为什么被关进来。新来的犯人回答说：我想我真是倒霉。几天前我在街上走的时候，看到一根脏绳子，以为没人要了，便捡起来带了回家。 

　　但是，捡一根绳子带回家并不犯法啊！ 

　　我告诉过你我倒霉了吧？那个人叹了口气，麻烦的就是我没有注意到绳子的那一头还有一头公牛。