exercise不可數名詞的用法：
（身體或腦力的）活動，鍛煉，運動：
�。�1）Swimming is good exercise.
游泳是有益的運動。
�。�2）I don't get much exercise sitting in the office all day.
我整天坐在辦公室很少運動。
（3）The mind needs exercise as well as the body.
大腦同身體一樣需要鍛煉。
行使；運用；使用：
�。�1）the exercise of power by the government
政府權力的行使
�。�2）the exercise of discretion
自行決定權的行使