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

【释义】君子的言论，真实可靠且有证据。

你必须相信过程并相信自己。

No matter how good you get you can always get better, and that's the exciting part.

Leadership means making tough decisions even when they are unpopular.

The best part about being a woman is the power to bring life into the world.

怪物是真的，鬼魂也是。它们住在我们心里，有时，它们会赢。