单项选择题
A.avoid unnecessary pints inventory
B.keep torsional vibration constant
C.use existing supports and braces
D.maintain specified injection characteristics
单项选择题 Friction, engine wear and oil consumption in a diesel engine are directly related to the （）.
单项选择题 Two important considerations for the proper lubrication of a diesel engine include the delivery of the oil in sufficient amount and the （）.
单项选择题 In a naturally aspirated diesel engine, the volume of air intake is directly related to engine （）.