单项选择题
A.fuel oil B.cooling water C.steam D.power
During working of an air compressor, （） should be drain...
单项选择题During working of an air compressor, （） should be drained.
A.oil sump B.oil separator C.outlet pipe D.inlet pipe
A.inter cooler B.cylinder C.outlet pipe D.inlet pipe
Before starting an air compressor, It should be （）.A.un...
单项选择题Before starting an air compressor, It should be （）.
A.unloaded B.primed C.filled with water D.greased
