单项选择题
What harmful condition can result if a diesel engine is operated at very light loads for long periods of time?（）
A.increased carbon buildup B.burning of intake valves C.excessive firing pressures D.increased fuel consumption
单项选择题 Turbocharged four-stroke/cycle diesel engines utilize valve overlap for（）.
单项选择题 Operating a propulsion diesel engine at less than 30% of designed normal load for prolonged periods will result in （）.
单项选择题 A dirty fuel oil filter element can be detected by （）
