Keeping a proper balance between study and rest keeps us energetic.
在学习和休息之间保持适当的平衡，能使我们精力充沛。
We become more energetic, more alert, better able to take effective action.
我们变得更有活力、更警觉、更有能力采取有效的行动。
You should exercise more so as to keep energetic and you can work efficiently.
你应该多运动以保持精力充沛，才可以有效地工作。