如果你在上课的时候总是不能集中精神,感觉头脑有点迟钝或是记忆力下降,你多半会告诉自己:“最近学习太累,压力太大了。要是能美美地睡上一觉该有多幸福啊!”不过,也许你缺乏的不只是睡眠,还可能是水。你一定会说,感觉口渴的时候我就去喝水了,怎么还会缺水呢?问题就出在这里啦。当你感觉口渴时,你的身体其实已经缺水一段时间了。换句话 If you can not always concentrate, feel a bit sluggish or have a memory loss during class, you probably tell yourself: “I was too tired to study lately and was over stressed. Happiness! ”However, maybe you are not only lacking in sleep, but also water. You must say, when I feel thirsty, I go to drink water, how can I still have water? The problem lies here. When you feel thirsty, your body is actually short of water for some time. In other words