单项选择题
A.TBN number B.viscosity C.temperature D.foaming
The lower section of a piston is called the （）.A.landB....
单项选择题The lower section of a piston is called the （）.
A.land B.skirt C.crown D.plate
The diesel engine valve subjected to most severe condit...
单项选择题The diesel engine valve subjected to most severe conditions of service is the （）.
A.cylinder exhaust valve B.air starting valve C.air inlet valve D.cylinder relief valve
A piston in a four-stroke/cycle diesel engine makes fou...
单项选择题A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.
A.crankshaft revolution B.mechanical cycle of operation C.period of two combustion cycles D.cycle of two events
