单项选择题
A.lobe type B.screw type C.axial piston type D.volute type
When an auxiliary boiler is panting and emitting black ...
单项选择题When an auxiliary boiler is panting and emitting black smoke, you should （）.
A.increase the fuel oil temperature B.decrease the fuel oil temperature C.decrease the fuel oil supply pressure D.increase the air supply
Close the （）.A.keywayB.shaftC.packingD.valve
单项选择题Close the （）.
A.keyway B.shaft C.packing D.valve
Which pump is the self-priming pump?（）A.turbineB.centri...
单项选择题Which pump is the self-priming pump?（）
A.turbine B.centrifugal C.ejector D.mixed flow
