甲类三管英语考试试题.doc

In the two stroke diesel engine, it is designed so that the oil impingement is timed to proceed only on the piston ring belt during ________.
A. compression stroke B. suction stroke C. expansion stroke D. exhaust stroke
In a four stroke engine, which process lasts the longest period?
A. exhaust and suction process B. suction and compression process
C. combustion and exhaust process D. working and exhaust process
On what do you depend having the air cooler of main engine chemically washed?
A. increased air pressure difference before and aft air cooler
B. reduced exhaust temperature in all cylinders
C. reduced temperature difference between water inlet and outlet
D. both A and C
When occurring a fire in the scavenge air box, the following measures should be taken except for________.
A. reducing speed to SLOW and asking bridge for permission to stop
B. stopping the fuel oil supply
C. switching-on the auxiliary blowers
D. putting the scavenge air box fire extinguishing equipment into function
Continuous surging of turbocharger can be caused by________.①crash stop of engine; ②increased back pressure after .;③fouled or damaged turbine nozzle ring.
A. all are correct B. ②and ③ are correct
C. none of the above is correct D. ① only is correct
When a sudden increase in steam demand occurs from the boiler, the water level in the drum at the higher pressure will_______.
A. rise quickly B. rise slowly
C. drop quickly D. drop slowly
On modern ships, centrifugal pump with a self-primer has replaced reciprocating pump as bilge pump because________.
A. centrifugal pump is cheaper than reciprocating pump
B. the size of centrifugal pump with same capacity is smaller than that of reciprocating pump
C. centrifugal pump makes maintenance easier than reciprocating pump dose
D. all of the above
Which cause of following will not lead to refrigerati