The state, therefore, has not existed from all eternity. There have been societies that did without it, that had no notion of the state or state power. At a certain stage of economic development, which was necessarily bound up with the split of society into classes, the state became a necessity.

如同海水奔流向东，世间万物都在革新中趋向大同境界。

在田野的寂静中，过去的回声越来越响亮。

群星不会因为像萤火虫而怯於出现。

PID控制器是控制工程师的通用工具，适用于各种各样的过程。

要解决复杂的问题，我们必须首先理解产生这些问题的系统。

真理的光芒常常在困境中闪耀。

I can never be safe; I always try and go against the grain. As soon as I accomplish one thing, I just set a higher goal. That's how I've gotten to where I am.