once every crankshaft revolution
once every two crankshaft revolutions
once every piston stroke
twice every piston stoke
第1题：
less even torque
higher cylinder head temperatures
fewer power strokes per revolution
greater weight/size requirements
第2题：
one half crankshaft speed in a two-stroke cycle diesel engine
crankshaft speed in a two-stroke cycle diesel engine
two times crankshaft speed in a two-stroke cycle diesel engine
one-fourth times crankshaft speed in a four-stroke cycle diesel engine
第3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.The direction of pressure on the journal in four-stroke engine is continuously
B.positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
C.four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
D.Low-stroke engines usually consume less lube oil than four-stroke engines
第4题：
Exhaust and scavenging
Scavenging and compression
Ignition and expansion
Exhaust and compression
第5题：
insufficient lubrication
improper piston cooling
blow-by
overload operation
第6题：
a single, long-stroke, slow-speed, turbocharged, two-stroke diesel engine
a single, long-stroke, medium-speed, turbocharged, four-stroke diesel engine
two medium-speed, turbocharged, four-stroke diesel engines
a variable-speed AC generator
第7题：
starting air and fuel pumps
piston cooling pumps
exhaust valves
all of the above
第8题：
once every crankshaft revolution
once every two crankshaft revolutions
once every piston stroke
twice every piston stroke
第9题：
most critical in a four-stroke cycle diesel engine
most critical in a two-stroke/cycle diesel engine
most critical in a four-stroke/cycle diesel engine if it is turbocharged
of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
第10题：
The direction of pressure on the journal in four-stroke engine is continuously
positive feed lubricators are installed on all bearings of four-stroke engine, whereas as a splash feed system is used on tow-stroke engine
four-stroke engines usually utilize a heavier grade of oil than tow-stroke engines
Low-stroke engines usually consume less lube oil than four-stroke engines