一枝粉笔被老师轻而易举地折断了，几乎是悄无声息。这是为什么呢？我想，假如是一根铁棒，会被折断吗？不会。粉笔本身太脆弱，它只是由一些石膏粉经过简单加工而成的，它没有千锤万凿、烈火焚烧的经历，当然比不上铁。由此我想到：“打铁还须自身硬。”一个人要想在激烈的竞 A piece of chalk was easily broken by the teacher, almost quietly. Why is this? I think, if it is an iron bar, will be broken it? will not. Chalk itself is too fragile, it is simply made of some gypsum powder through simple processing, it does not have a thousand and one thousand guns, burning fire experience, of course, less than iron. From this I think: “Blacksmith must own hard.” A person to think in the fierce competition