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

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

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

Hydraulic pumps most commonly used in steering systems are of the （）.

A、lobe type

B、screw type

C、axial piston type

D、volute type

The （） returns the pump operating rod to mid position as soon as the helmsman stops turning the wheel.

A、hunting gear

B、cut-off level

C、servo-motor

D、swivel block

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