单项选择题
A.the amount of lube oil additives increase
B.piston speeds increase
C.injection pressure decrease
D.engine speeds decrease
单项选择题 To reduce the weight of the reciprocating parts, pistons of high-speed engines are made considerably shorterThis results in （）
单项选择题 Which of the following statements concerning cylinder liner wear is true?（）
单项选择题 If clearance between a piston and the cylinder wall is excessive, piston slap will occurThe slap itself is caused by （）