轮机英语单项选择题每日一练(2019.12.27)

单项选择题
（） provide the water to the pistons.
A.Pneumatic pipes
B.Hydraulic pipes
C.Telescopic pipes
D.Operating gas pipes
单项选择题
（）does not belong to the mooring trial item.
A.generator sets running trial
B.shafting intensity trial
C.the trail for pumps that working for ME
D.ME safety devices trial
单项选择题
While inspecting the main bearings on a diesel engine you find impregnated dirt and scratches in the bearing surface you would, therefore, suspect that （）
A.the bearing had been overheated
B.water was present in the oil
C.the lube oil was not being properly filtered
D.the maximum allowable bearing pressure had been exceeded
单项选择题
The frequency output of an operating alternator is controlled by the （）.
A.relative speed of the rotor poles
B.number of turns of wire in the armature coil
C.strength of the magnets used
D.output voltage
单项选择题
When the vessels steering wheel on the navigation bridge is turned, the difference existing between the position of the wheel and that of the rudder is known as （）.
A.proportional band
B.the error signal
C.the reset signal
D.feedback