可持续采石不是选择，而是我们对后代的责任。

The only limit to our realization of tomorrow will be our doubts of today.

语言既是桥梁也是障碍，它连接我们也分隔我们。

What is the difference between a Turing machine and the modern computer? It's the same as that between Hillary's ascent of Everest and the establishment of a Hilton hotel on its peak.

The more time I spent on mathematics, the more excited I got.

译文：天气不寒冷，地面就不会被冻住，人没有到伤心的时候就不会流泪。赏析：人的言行总是随着外物的变化而变化。不以物喜不以己悲，其实很难做到的。