其他节日纪念过去；植树节则为未来着想。

理解一个句子意味着理解一种语言。

数学不是沿着一条清理得很好的高速公路小心行进，而是进入一个陌生的荒野的旅程，探险者常常会迷路。

I constantly see people rise in life who are not the smartest, sometimes not even the most diligent, but they are learning machines. They go to bed every night a little wiser than they were when they got up.