单项选择题 In a diesel engine, when refitting piston rings you should （） Ⅰ.check the ring gap at the smallest diameter of the cylinder Ⅱ. Remove carbon from the ring groove

单项选择题 In a diesel engine, an integral liner is one in which the cooling water （） Ⅰ.flows through the cylinder liner jackets Ⅱ.touches the outer side of the liner

单项选择题 Excessive lube oil consumption can result from worn or broken（）