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Natural experiments are a powerful tool for understanding causal relationships in the real world.
我们阅读是为了知道自己并不孤单。
我们不是从祖先那里继承土地;我们是从子孙那里借来的。
Thinking is the hardest work there is, which is probably the reason why so few engage in it.
你必须相信你制定的长期计划,但你需要短期目标来激励和启发你。
The greatest stories are those that reveal the complexity of human nature.