单项选择题
A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.
A.crankshaft revolution B.mechanical cycle of operation C.period of two combustion cycles D.cycle of two events
单项选择题 The effective stroke of a constant-stroke, individual, fuel injection pump is varied by the （）.
单项选择题 The ability of a fuel particle to travel into the combustion chamber before burning is called （）.
单项选择题 Proper atomization of fuel in diesel engine combustion chambers will （）.
