in the evening.Mother asks her little boy,"Darling,what does the teacher teach you today?""Nothing,Mom"answeres the boy,"But I teach her.""Really?My dear!""Yes,she asks me what is one plus two,and I tell her three."nothing[ˈnʌθɪŋ]：没有东西; 没有事情tell[tɛl]：告诉，辨别