单项选择题
Improper cooling of a diesel engine cylinder liner due to the accumulation of scale deposits may cause （）.
A.low compression pressure B.increased piston wear C.increased cylinder lube oil consumption D.poor contact between compression rings and liner
单项选择题 In describing engine operation, what does the term “cycle” mean?（）
单项选择题 An advantage of aluminum pistons, when compared to cast iron pistons is （）.
单项选择题 Which of the combustion parameters listed is used in a diesel engine, but NOT related to the injection system?（）
