看到老师在黑板上画的一个圆，我便想到法国数学家、哲学家笛卡儿的名言：“愈学习，愈发现自己的无知”。这句话说得多好啊,圆把这句话表现得多么生动贴切呀!比方黑板便是无边无际的海，小圆的面积越来越大，随之圆的周长也越来越长，自然与学海的接触越来越多，就更加体会出 Seeing a circle drawn by the teacher on the blackboard, I think of the famous French mathematician and philosopher Descartes’s saying: “The more you learn, the more you discover your own ignorance.” Well, how well do you say this sentence, and how vivid it is in the circle! For example, the blackboard is an endless sea. The area of ​​the small circle is getting bigger and bigger, and the circumference of the circle is getting longer and longer. With more and more contacts between nature and the sea of ​​learning, we will realize more.