Always ensure that the turning gear is（）, even at the quay, the wake from other ships may turn the propeller and thus the engine.

A.supply clean air to the measuring compartment of the units for more accuracy
B.generaate the pressure required for the extraction of the oil mist from the
C.generate the pressure required for the extraction of the oil mist from the crankcase
D.supply clean air to the measuring track of the units for more accuracy

A.avoid false alarms as a result of condensing water vapor
B.avoid danger of frost under very cold weather
C.reduce the viscosity of the crankcase atmosphere in order to improve the fluidity
D.keep the temperature of the oil mist detectors in an appropriate range

A.The oil mist detectors
B.The smoke detectors
C.An oily water monitor
D.Oil discharge monitoring and controlling system