Every problem in mathematics is an opportunity to learn something new.

互联网的精髓是自由和分享。

Coal will remain a vital energy source, but only if we evolve with the times.

解释：齐国是强国，利用它的强大进攻宋国，让他逞强，燕国就可以乘机打败齐国；齐国是大国，利用它的大国野心吞并宋国，增加土地，燕国就可以乘机进攻。

I think the most important thing in life is to be true to yourself.

我们都是自己故事中的英雄。