单项选择题
A.only the replacement of the entire pump would be acceptable
B.the injection pump and injection nozzle must be replaced
C.either the barrel or plunger must be replaced
D.the barrel and plunger must be replaced as a unit
单项选择题 In a modern internal combustion diesel engine, the load carrying part of the engine is referred to as the（）
单项选择题 Black smoke exhausting from an operating diesel engine is an indication of poor combustion which may be caused by （）
单项选择题 Increasing the compression ratio of a diesel engine while maintaining the designed rate of fuel flow will result in （）