n.

1. 活力，干劲[U]
   They are working with energy.

   他们正在干劲十足地工作。

2. 精力，能力[U][P]
   They devoted all their energies to the job.

   他们把自己的全部精力投入这项工作。

3. 【物】能，能量[U]

n.

1. the strength and vitality required for sustained activity.
   ▸ (energies) a person's physical and mental powers as applied to a particular activity.
2. power derived from physical or chemical resources to provide light and heat or to work machines.
3. Physics  the property of matter and radiation which is manifest as a capacity to perform work.