单项选择题
Either a low injection pressure or a leakage of piston rings is able to lead （）.
A.a high exhaust temperature B.a high smoky exhaust C.a high output D.a high compression
单项选择题 Each piston stuffing box is provided with two sealing rings and three（）
单项选择题 Each journal and pin should be examined for （） and grooving.
单项选择题 Each cylinder liner on the marine medium speed engines （）.
