单项选择题
How many power strokes per crankshaft revolution are there in an eight cylinder, two stroke/cycle diesel engine?（）
A.One B.Two C.Four D.Eight
单项选择题 The highest pressure in a diesel engine cylinder normally occurs （）.
单项选择题 What causes diesel fuel to be ignited in the cylinder of an operating diesel engine?（）
单项选择题 The main purpose of the piston oil scraper rings is to （）.
