operating charge的用法和樣例：
例句
- Initial investment and operating costs usually favor the large single continuous digester.
較低的初始投資和運行費用通常使得間歇式蒸煮更受歡迎。 - The experimental results showed that dosing PAC was an effective way to increase membrane flux and decrease the operating cost of MBR.
向膜生物反應器內投加粉末活性炭是提高和維持膜通量的有效途徑，并且可以降低運行費用。
