"The mind is its own place, and in itself can make a heaven of hell, a hell of heaven."
心灵是自己的地方，它本身可以把地狱变成天堂，把天堂变成地狱。
数学是理性的音乐。
Free trade is the key to the prosperity of a nation.
危机中往往隐藏着机遇，关键是如何把握。
"The best way to learn is to do it, to make mistakes, and to learn from them."