Studies show that even mild dehydration decreases alertness, increases fatigue, and negatively affects mental concentration.

研究显示，即便是轻微的脱水症状都能降低注意力甚至增加疲劳感，让专注力下降。

For example, you may find your peak times for mental concentration and studying, and schedule study blocks for your most difficult classes during these periods.

例如，你可能会发现你的精神集中和学习的高峰期，并在这些期间为你最困难的课程安排学习单元。