"The most important thing in empirical work is to be clear about the question you are trying to answer."
【释义】若不是在正午半夜的时候,连太阳和月亮都看不见。描绘了三峡峡谷幽深、遮天蔽日的景象。
地壳在某种程度上是过去时间的博物馆。