energy grade line

例句：

1. 1.The company has set a new energy efficiency standard for the industry.
   该公司为该行业设定了新的能源效率标准。
2. 2. The engineer used the energy grade line to determine the optimal operating point.
   工程师利用能量等级线来确定最优操作点。
3. 3. The energy grade line is crucial for determining the overall performance of the system.
   能量等级线对于确定系统的整体性能至关重要。