单项选择题
A.cylinder cover B.cooling water C.oil cup D.drain valve
Open the （）before starting an air compressor.A.unload v...
单项选择题Open the （）before starting an air compressor.
A.unload valve B.cooling water C.oil cup D.sump
Supply the （）before starting an air compressor.A.fuel o...
单项选择题Supply the （）before starting an air compressor.
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
