一些代数恒等式可以用平面图形的面积来表示.

一些代数恒等式可以用平面图形的面积来表示.
一些代数恒等式可以用平面图形的面积来表示.

一些代数恒等式可以用平面图形的面积来表示.
A Boy and His Tree
A long time ago,there was a huge apple tree.A little boy loved to come and play around it every day.He climbed to the tree top,ate the apples,took a nap under the shadow… He loved the tree and the tree loved to play with him.
　　Time went by…The little boy had grown up and he no longer played around the tree.
　　One day,the boy came back to the tree and looked sad.“Come and play with me,” the tree asked the boy.
　　“I am no longer a kid,I don’t play around trees anymore.” The boy replied,“I want toys.I need money to buy them.” “Sorry,but I don’t have money…but you can pick all my apples and sell them.So,you will have money.” The boy was so excited.He picked all the apples on the tree and left happily.The boy didn’t come back after he picked the apples.The tree was sad.
　　One day,the boy returned and the tree was so excited.“Come and play with me.” The tree said.“I don’t have time to play.I have to work for my family.We need a house for shelter.Can you help me?” “Sorry,but I don’t have a house.But you can cut off my branches to build your house.” So the boy cut all the branches of the tree and left happily.
　　The tree was glad to see him happy but the boy didn’t appear since then.The tree was again lonely and sad.One hot summer day,the boy returned and the tree was delighted.“Come and play with me!” the tree said.
　　“I am sad and getting old.I want to go sailing to relax myself.Can you give me a boat?” “Use my trunk to build the boat.You can sail and be happy.” So the boy cut the tree trunk to make a boat.He went sailing and did not show up for a long time.
　　Finally,the boy returned after he left for so many years.“Sorry,my boy.But I don’t have anything for you anymore.No more apples for you.” the tree said.“ I don’t have teeth to bite.” The boy replied.“ No more trunk for you to climb on.” “I am too old for that now.” the boy said.“I really want to give you something…the only thing left is my dying roots.” The tree said with tears.“I don’t need much now,just a place to rest.I am tired after all these years.” The boy replied.“Good!Old tree roots are the best place to lean on and rest.Come here,please sit down with me and have a rest.” The boy sat down and the tree was glad and smiled with tears…
　　This is a story of everyone.The tree is our parent.When we were young,we loved to play with Mom and Dad… When we grow up,we leave them,and only come to them when we need something or when we are in trouble.No matter what,parents will always be there and give everything they could to make you happy.You may think that the boy is cruel to the tree but that