问题：
[单选] The required amount in the change of speed necessary before a governor will make a corrective movement is known as （）.
speed droop。sensitivity。stability。promptne。
问题：
[单选] Which of the following problems may occur if the opening pressure of a fuel injection nozzle is greater than specified by the engine manufacturer?（）
The amount of fuel injected will be increased。The start of injection will be retarded。The nozzle will permit fuel to dribble。The spray pattern will be distorted。
问题：
[单选] Exhaust valve grooving and corrosion is caused by certain components of residual fuel oilThese components are sodium, sulfur, and （）.
vanadium。carbon。copper。ash。
问题：
[单选] High firing pressures and a low exhaust temperature in a diesel engine may result from （）.
decreased piston to cylinder head clearance。increased exhaust system back pressure。early fuel injection timing。low scavenge air temperature。
问题：
[单选] Poor combustion in a diesel engine can be caused by （）.
high compression pressure。low intake air temperature。low exhaust pressure。high scavenge air pressure。
问题：
[单选] The longer the ignition delay period occurs in a diesel engine, the （）.
less fuel will enter the cylinder。lower will be cylinder compression temperatures。more complete will be fuel combustion。more rapid will be the rise in combustion pressure。
问题：
[单选] Which term describes piston pins having bearing surfaces in both the piston bosses and connecting rod eye?（）
Stationary。Full floating。Semi-floating。Free rolling。
问题：
[单选] Which of the following devices is common to both mechanical and hydraulic governors?（）
Direct linkage between the ball-head and fuel rack。A servomotor。A compensating device。Flyweight。
问题：
[单选] On most diesel engines, the governor controls the output speed by （）.
controlling the amount of fuel injected into the cylinders。varying the speed of the turbocharger。adjusting the compression ratio。changing the timing of the fuel injection camshaft。
问题：
[单选] Any increase in the exhaust back pressure of a four-stroke/cycle diesel engine will （）.
reduce engine horsepower output。aid in silencing the exhaust noise。increase the mean effective pressure。contribute to effective cylinder scavenging。
