自动控制的根本问题是在存在干扰的情况下维持期望状态。

A book is a garden, an orchard, a storehouse, a party, a company by the way, a counselor, a multitude of counselors.

The most dangerous phrase in the language is, 'We've always done it this way.'

数学的进步是通过不断质疑已建立的真理来实现的。

The past is never dead. It's not even past.