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单选题
In a four-stroke engines the camshaft rotates at （）.
A
half the engine rotational speed
B
twice the engine rotational speed
C
the engine rotational speed
D
four times the engine rotational speed
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单选题What is the speed of the crankshaft in a four-stroke/cycle engine when the camshaft is turning at 750 rpm?（）A
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考题
单选题In a four-stroke engine the camshaft rotates at （）.A
half the engine speedB
twice the engine speedC
the engine speedD
four times the engine speed
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单选题The reversing cams of some four-stroke/cycle diesel engines are brought into position by （）A
sliding the camshaft along its axisB
rotating the cam 180C
rotating the cam followers 180D
moving the idler sprockets in the drive chain
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单选题The size of the exhaust valve opening is （）A
most critical in a four-stroke cycle diesel engineB
most critical in a two-stroke/cycle diesel engineC
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单选题Marine four-stroke diesel engines are mainly （）.A
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单选题（）, so they are widely used on board ship nowadays.A
Diesel engines have more advantages in comparison with gasoline enginesB
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单选题Proper lubrication of the main bearings is more easily obtained in a single acting, four-stroke/cycle diesel engine than in a tow-stroke/cycle diesel engine because（）.A
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单选题The rotor of the hydraulic motor rotates at a speed proportional to the （）.A
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A and BD
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考题
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考题
单选题When the direction handle of telegraph is moved, the relative position of camshaft and crankshaft will be（）A
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单选题（）uses one or two high pressure pumps for all the cylinders with one more standby, while（）have a separate high-pressure pump for each cylinder.A
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A two-stroke engine；four-stroke engines
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单选题With four-stroke engines, it takes four revolutions of the crank shaft to make （） power stroke(s).A
1B
2C
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单选题The purpose of the skirt or trunk in four-stroke cycle engines is to act in a similar manner to a （）.A
crossheadB
crownC
piston rodD
connecting rod
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单选题Turbocharged four-stroke/cycle diesel engines utilize valve overlap for（）.A
improving cylinder scavengingB
preheating the combustion chamberC
reducing air charge densityD
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单选题The camshaft on a four-stroke/cycle diesel engine provides a means to operate the （）.A
fuel injectorsB
exhaust valvesC
intake valvesD
all of the above
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单选题In a four-stroke/cycle diesel engine, the camshaft rotates at （）A
twice the crankshaft speedB
half the crankshaft speedC
the same speed as that of the crankshaftD
a speed independent of that of the crankshaft
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