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实证研究中最重要的是要清楚你想要回答的问题。
"The most important thing in empirical work is to be clear about the question you are trying to answer."
"The past is never dead. It's not even past."
Challenges are what make life interesting; overcoming them is what makes life meaningful.
能源的真实成本必须同时考虑其生产和遗留影响。