I'm a Letter-carrier
A doctor told his patient there was nothing really the matter with him. " All you requir is more outdoor life; walk two or three miles regularly everyday; by the way, what's your business? "
　" I'm a letter-carrier." the patient answered.

我是邮递员

　医生告诉他的病人说他没有什么毛病。“你现在需要的就是更多的　户外生活；天天坚持走二三里路；顺便问一下，你是干什么工作的？”
　“我是邮递员。”病人回答。