如果你自由，你就不可预测。

Fear can hold you prisoner. Hope can set you free.

The most common form of despair is not being who you are.

At the close of our studies， we knew all the past of physics， but nothing of the present and the future.

学习之道，没有什么比能够弄清事物的始末，来龙去脉更重要的。