海鲜的真正成本不在价格标签上，而在生态系统中。

The purpose of life is not to be happy. It is to be useful, to be honorable, to be compassionate, to have it make some difference that you have lived and lived well.

Sometimes the most important thing in a whole day is the rest we take between two deep breaths.

The beauty of instrumental variables is that they allow us to see the world in a new light.

爱是一个战场，但它是一个值得为之奋斗的战场。