单项选择题 A two-stroke diesel engine exhaust temperature will be lower than a four-stroke diesel engine of the same displacement because the （） (1) MEP is lower and the scavenging air is cooling the exhaust gases (2) valve overlap in a four-stroke

单项选择题 A magnetic strainer is used in the diesel engine reduction gear oil system to remove small particles of（）.

单项选择题 Which of the substances listed is satisfactorily removed from the fuel by a centrifugal oil purifier?（）