Which of the followings needs not to be considered during bunkering?（）
A、All scuppers plugged by carpenter
B、Tanks sounded from time to time
C、Watch kept for leakage
D、Take oil samples
Hydraulic pumps most commonly used in steering systems are of the （）.
A、lobe type
B、screw type
C、axial piston type
D、volute type
Which of the listed devices is used to measure pressure and convert it to an electrical signal?（）
A、Transducer
B、Reducer
C、Transformer
D、Rectifier
If you must make an electricity connection in a poorly accessible spot, solder it and seal it against （）
A、metal
B、wood
C、water
D、plastic
A transformer in an electric circuit serves to （）
A、generate its own electrical power
B、transform electrical energy into mechanical energy
C、increase or decrease circuit voltage as required
D、convert AC current to DC current
Emergency generator is installed on board mainly to （）
A、connect to the busbar when the load increasing
B、supply power specially to charging panel
C、be put into operation during the ship arriving at or leaving port
D、ensure the power supply to critical equipment after the main switchboard out of power
