单项选择题
A.Proper refrigerant charge B.Faulty expansion valve C.Insufficient refrigerant D.Solenoid valve stuck open
Moisture in a refrigeration system can cause （）.A.freez...
单项选择题Moisture in a refrigeration system can cause （）.
A.freezing the expansion valve closed B.corrosion of system piping C.improper temperature regulation D.all of the above
When the propeller blades are integral with the hub, th...
单项选择题When the propeller blades are integral with the hub, the propeller is called a （）.
A.built up propeller B.solid propeller C.controllable pitch propeller D.suction back propeller
The tendency of a flammable liquid to vaporize is indic...
单项选择题The tendency of a flammable liquid to vaporize is indicated by its （）.
A.ignition temperature B.flash point C.flammable range D.convection index
