Making something variable is easy. Controlling duration of constancy is the trick.

In times of change, the learners inherit the earth, while the learned find themselves beautifully equipped to deal with a world that no longer exists.《Steel and Strategy》

采矿技术的创新不是可选项，而是决定采掘业未来的生命线。

世界历史可以这样总结:强国总行不义。等到他们醒悟了,他们不已经不再强了。

解释：神态傲慢，谁还愿意和你相处呢？最洁白的东西好像十分黑暗，最道德的人好像有所不足。