working costs的用法和样例：
例句
- Initial investment and operating costs usually favor the large single continuous digester.
较低的初始投资和运行费用通常使得间歇式蒸煮更受欢迎。 - But the lifetime operational costs of wireless LANs can be substantially less than those of wired LANs, particularly in environments requiring frequent modification.
但在寿命周期内，无线局域网的运行费用大大低于有线局域网，尤其是在需要频率调制的环境中时。
