老年并不有趣，直到你真正步入老年。
Old age is not interesting until one gets there.
Darkness cannot drive out darkness: only light can do that. Hate cannot drive out hate: only love can do that.
In mathematics, the simplest questions often lead to the most profound discoveries.
The least I can do is speak out for those who cannot speak for themselves.
"There is only one real sin, and that is to persuade oneself that the second-best is anything but the second-best."
True progress happens when we balance economic growth with environmental stewardship.
实现任何有价值的事情的三个重要要素是：努力工作、坚持不懈和常识。