她大多数晚上锻炼，通常是跑步。

She ___exercises most evenings, usually by running.

健身房的一次锻炼会锻炼所有主要肌肉群。

A work-out in the gym will ___exercise all the major muscle groups.

我和莎拉在健身房，我们正在锻炼时听到汤姆和约翰在谈论它。

I was at the gym with Sarah, we were ___exercising when we heard Tom talking about it with John.