当第一萃取塔压差波动时应检查()并作相应处理。 ["检查硅油添加情况","判断塔内有无堵塞","检查相关调节阀工作状况","检查压差导压管拌热情况"]
油污的极性可分为() ["A、极性","B、非极性","C、水性","D、非水性"]
发电机的绝缘试验项目有哪些?
涂装方法的发展方向是:() ["A、自动化","B、无污染","C、高效化","D、人工化"]
往复泵理论流量只与泵缸或活塞的()及每一周期内吸排液次数等有关。 ["冲程","截面积","阀开度","往复频率"]
简述同步电动机失磁后的后果及其处理方法?