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

The pressure range between the system cut in and cut out pressures in a refrigeration unit is known as（）

A、opposing operational drag

B、pressure distribution

C、differential

D、system purge

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

While loading bulk oil, you notice oil on the water near the bargeWhich of the following actions should you carry out FIRST?（）

A、Search the vessel for leaks

B、Notify terminal superintendent

C、Stop loading

D、Notify the Coast Guard

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

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

A、lobe type

B、screw type

C、axial piston type

D、volute type