The math teacher drew a coordinate system on the blackboard, put down the chalk in his hand, swallowed and began to teach students how to write the coordinates of a point. At this time, old Hyun Positive was prone on his desk, biting his pen, and couldn't listen to the math teacher. The sun is like a woman in her thirties, showing off her coquettish posture. The sun stung the old porch to sleep. The old porch drew the curtain, "Zhi-"The old porch turned around and saw his sharp eyes through the math teacher's glasses. "Liu Xuan! What are you doing? ! Do you think you are smart? I tell you, I have taught more students who are smarter than you. what do you want to do? You! " The math teacher became more and more angry and began to blush and have a thick neck. It seems that he is about to have a heart attack. Lao Xuan thought that the math teacher must feel that he was the landlord of the evil old society. He is the representative of the poor peasants and wants to strangle himself. Linguistically speaking, this metaphor is not appropriate, but Lao Xuan feels that the math teacher can only express his hatred of gnashing his teeth. The math teacher calmed down. "good! Liu Xuan, then tell me what the coordinates are. " Old porch pouted, "well ... let me think, oh! I don't know, "the old porch smiled cunningly and sat down happily. What will happen next? First, the teacher starts swearing, then the members of the Commission for Discipline Inspection will record their disciplinary actions, then they will be called to the office, and finally they will be punished for mopping the floor. Everything is logical, and Lao Xuan suddenly feels that school public health has its own credit.

The good student next to him sarcastically said, "You are so smart that you really don't know what the coordinates are?" . Lao Xuan suddenly thought about the math teacher's question "What are the coordinates?" Lao Xuan picked up the bitten pen and brushed it hard on the paper. He wrote: If it is good to be greater than zero, it is bad to be less than zero, the X axis is life, and the Y axis is learning, then:

(0, y), (y≥0) It was a childhood that passed by in a hurry.

The old porch in childhood was just Xiao Xuan. At that time, Xiao Xuan was not as bad or even excellent as the old porch, but those cleverness were only useful to parents. Mother always takes a group of aunts home. Mom will let Xiao Xuan watch Teletubbies alone in the room, and Xiao Xuan will run into the room, happily turn on the TV and watch Teletubbies carefully. Teletubbies have nothing to look at, just a few dolls with antennas twisting their butts together until Xiao Xuan becomes an old porch, and he can't understand his original behavior. When the aunts saw obedient Xiao Xuan, they would inspire motherhood, and they would pounce on Xiao Xuan like animals, touching his head and exclaiming, "What a lovely child! I'm sure I can be an old Tsinghua in the future. Which is better than my home! " Aunties always say that. Mothers always like to compare with their children. Before comparing, they always criticize the children first, and then praise them. Several years later, Xiao Xuan finally learned in the Chinese book that this is called restraining first and then promoting, not to mention the extremely low probability of being admitted to Tsinghua. How did this happen in Xiao Xuan? But Xiao Xuan can never deny her knowledge of her mother's generation, or her mother will be angry. If her mother gets angry, the consequences will be serious. So Xiao Xuan just obeyed Nuo Nuo's nod and went shopping happily with the money given by his aunts.

This shows that the old porch in childhood is very clever.