单项选择题
Metal particles accumulated from the wearing of components in a diesel engine can result from lube oil that has been contaminated with（）.
A.abrasive particles B.metallic oxides C.corrosive acids D.any or all of the above
单项选择题 In a diesel engine, late fuel injection is indicated by black or gray exhaust smoke with（）
单项选择题 The cylinder liner forming the cylinder wall and the inside of the water jacket is called a（）
单项选择题 Which of the listed devices could be used as a substitute for a ring grooving tool?（）
