Whant causes humans to become thirsty?Why can't we maintain life without drink so much water?

问题描述:

Whant causes humans to become thirsty?Why can't we maintain life without drink so much water?
小女学识浅薄,望各位大虾鼎力相助,感激不尽!

是什么原因让人类感到口渴呢?
为什么我们不喝这么多的水就不能维持我们的生命呢?