不用圆规和曲尺，就不能画出方形和圆形。比喻做事要遵循一定的法则。
The man in the planning room, whose specialty under scientific management is planning ahead, invariably finds that the work can be done better and more economically by a subdivision of the labor.
The only true wisdom is in knowing you know nothing.
Silence can be as powerful as words, if you know how to listen.
The structure of DNA was a puzzle that demanded to be solved.
