Lock up your libraries if you like; but there is no gate, no lock, no bolt that you can set upon the freedom of my mind.
当每个人都试图同时出售时，流动性就消失了。
Leadership is about making tough decisions today that will benefit future generations.
数学是给不同事物以相同名称的艺术。
"The role of the infinitely small in nature is infinitely large."