Most hormone production is managed by a negative feedback system.

大多数激素的产生是由一个负反馈系统控制的。

Salt, on the other hand, is a negative feedback system — the desire for salt decreases as the sodium content of the body rises.

而盐是一种负反馈系统——人体对盐的欲望随着体内钠含量的增加而递减。