Which of the conditions listed will cause a refrigeration compressor to run constantly without simultaneously decreasing the temperature in the refrigerated space?( )

A．Shortage of refrigerant oil

B．Slight shortage of refrigerant

C．Excessive condenser cooling water flow

D．Faulty expansion valve

[单选题]Which of the listed conditions can be considered as the single greatest cause of accidents?A．SpeedB．Excessive knowledge or skillC．Human errorD．Excitement

[单选题]Which of the listed conditions can be considered as the single greatest cause of accident?A．SpeedB．Excessive knowledge or skillC．Human errorD．Excitement

[单选题]Which of the following problems can cause fluctuating pressures in the closed cooling system of a main propulsion diesel engine?（）A . Defective temperature controls in the systemB . Cavitation in the cooling water pumpC . Opened vent in the cooling s

[单选题]Which of the listed factors will indicate the most about the ability of a fuel to ignite in a diesel engine?A．ViscosityB．Sulfur contentC．Pour pointD．Cetane number

[单选题]Which of the substances listed is satisfactorily removed from the fuel by a centrifugal oil purifier?（）A . ImpuritiesB . Lube oilC . GasolineD . Diesel fuel

[单选题]Which of the listed pressure control valves would be used to establish the maximum operating pressure of a hydraulic system?A．Pressure-reducing valveB．Unloading valveC．Counterbalance valveD．Pressure-relief valve

[单选题]Which of the processes listed would be the most satisfactory method to use to lower the humidity of the air being circulated by an air conditioning system?A．Cooling the air to a temperature just above dew pointB．Heating the air to a point at which mo

[单选题]Which of the units listed is used to combust waste in the engine room?A．BoilerB．IncineratorC．Generator

[单选题]Which of the listed fire extinguishers cannot be easily recharged aboard ship?A．Soda acidB．Carbon dioxideC．Dry chemicalD．cartridge-operated Foam

[单选题]Which of the listed devices may be used as a digital device?A．variable resistorB．diodeC．strain gaugeD．thermistor