单项选择题
In a diesel engine cooling system, the high temperature alarm contact maker will be activated on excessively high water discharge temperature from the （）
A.raw water pump discharge B.expansion tank outlet C.cooling water heat exchanger D.outlet engine jacket water outlet
单项选择题 In a diesel engine, a cylinder liner should be replaced if it is （） Ⅰ.Scuffed Ⅱ.Scored
单项选择题 Under normal conditions, the main source of crankcase oil contamination is attributed to （）
单项选择题 Valve cages are used on some large diesel engines to （）
