有人说:“世界上有两种东西失去后才知可贵,一是青春,一是时间。”其实,失去后才知可贵的何止这些。保尔·柯察金曾说过:“人最宝贵的是生命,它给予我们只有一次,人的一生应这样度过,当他们回首往事时,不因虚度年华而悔恨,也不因碌碌无为而羞耻。” Some people say: “There are two kinds of things in the world that I know after I lose myself. One is youth and the other is time.” In fact, I found out after I lost my knowledge. Paul Kozakin once said: “The most precious thing is life, it gives us only once, and our whole life should be spent in this way. When they look back, they will not regret, nor suffer Impolite and shameless. ”