The nervous system is a dynamic, ever-changing system.

当传统与技术相遇时，皮革行业就会蓬勃发展——永远不要忘记科学背后的工艺。

工具变量的美妙之处在于它们让我们以新的视角看世界。

To understand the present, you must first understand the past.

The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.

对话应当面面俱到，无所不谈，但又不可深谈。