The world is full of stories, but only a few are worth telling.

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。

"The most important thing is to stay focused on the mission."

Mathematics is the language with which God has written the universe.

For me they normally happen, these career crises, often, actually, on a Sunday evening, just as the sun is starting to set, and the gap between my hopes for myself and the reality of my life starts to diverge so painfully that I normally end up weeping into a pillow.

The passion for office among members of Congress is very great, if not absolutely disreputable.