operational use作战使用operationaladj.操作的；运作的；可用的；作战的operational risk management操作风险管理operational characteristics操棕性,运行特性operational standardization经营标准Operational Needs Statement作战军需报表operational system analysis运算系统分析operational guiding thought作战指导思想operational decision scheme作战决策方案Operational Control Command操作员控制指令Operational Digital Network作战/运行数宇网络operational reference model运作参考模型

1. I need to buy car relay ,please and contact us.
   我们需要求购汽车继电器，请联系我们。
2. Only one relay is closed at any time.
   在某一时间，仅有一个继电器是闭合的。