单项选择题
A.chromed B.welded C.galvanized D.bolted
Either a low injection pressure or a leakage of piston ...
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
Each piston stuffing box is provided with two sealing r...
单项选择题Each piston stuffing box is provided with two sealing rings and three（）
A.packings B.piston rings C.distributor rings D.scraper rings
Each journal and pin should be examined for （） and groo...
单项选择题Each journal and pin should be examined for （） and grooving.
A.bridges B.recesses C.rears D.ridging
