单项选择题
A.backfire through the air intakes
B.develop less power under load
C.have high firing pressures
D.lift its cylinder relief valves
单项选择题 A condition that can increase the foaming tendency of lube oil is （）
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