useful energy

• 有效能,有用能

useful energy的用法和样例：

例句

1. A jet plane before takeoff has a certain store of available energy in its fuel.
   喷气式飞机起飞前已在燃料中贮存了一定的可资用能。
2. The State shall exercise strict administration of energy conservation in key energy-using units.
   第二十条国家对重点用能单位要加强节能管理。