煤炭曾是工业进步的支柱，但其未来必须平衡经济需求与环境责任。

The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.

自然实验可以为经济问题提供有价值的见解。

"To live is the rarest thing in the world. Most people exist, that is all."

及时采撷你的花蕾，旧时光一去不回，今天尚在微笑的花朵，明日便在风中枯萎。