Natural experiments are a powerful tool for understanding causal relationships in the real world.

Any woman who understands the problems of running a home will be nearer to understanding the problems of running a country.

生存的规则永远不会改变，无论你是在沙漠还是在办公室。

政府的职责是帮助那些无法自助的人。

The truth is always exciting. Speak it, then. Life is dull without it.

你不喜欢过新年吗？你能够重新开始，每人都有新的机会。

Life is too important to be taken seriously.

你必须成为你希望在世界上看到的改变。