单项选择题
A decrease in the flash point of diesel engine lube oil indicates the lube oil has become （）.
A.contaminated with sludge B.contaminated with carbon C.diluted with fuel oil D.diluted with water
单项选择题 The emulsion of the oil is mainly caused by （）.
单项选择题 Impurities in the fuel oil will affect the operation of the engine, which has （） the use of separator and some other devices.
单项选择题 The lube oil to lubricate the surfaces of the cylinder liners is spread over by the （）.
