Lubricating oil should be changed on a heavy duty diesel engine when（）. ["it gets dark in color","a sample rubbed between fingers feels thin","it has been in use for a specified interval","it no longer supports combustio"]
船舶电气工艺阶段的含义是什么？
营销是讲求方法的，如果具体的营销技巧与方法运用不当，直接影响营销活动的成败，但所有的营销技巧都是建立在充分了解尊重（）的基础上。 ["主管","自己","同事","顾客"]
分布式计算机系统是一种特殊的（）。 ["联机系统","计算机网络","具有通信功能的单机系统","都不是"]
When finish work on the oil separator, you should（）firstly. ["cut off the power","cut off the oil inlet","open guide water valve","close oil outlet value"]
电容器验收项目有哪些？
