Agriculture is not just a business; it's a way of life.

"Causal inference requires careful thought about the assumptions underlying your analysis."

眼睛不能同时看清楚两样东西，耳朵不能同时听清楚两种声音。

有两种自由——一种虚伪的自由，一个人可以为所欲为；一种真正的自由，一个人可以为所应为。