单项选择题
A.an overfilled expansion tank
B.excess chromate treatment of the jacket water
C.a clogged raw water sea suction
D.cavitation erosion of the heat exchanger tubes
单项选择题 The possibility of damage from operating a diesel engine at critical speeds is reduced by the use of（）.
单项选择题 The air supplied to a diesel engine is compressed to （） (1) provide heat for the ignition of the fuel (2) decrease injection delay
单项选择题 In a normally operating diesel engine, the main cause of lubricating oil contamination in the crankcase is a result of the （）.