单项选择题
A.splash method
B.mechanical force feed lubricators
C.detached sump method
D.internal cooling passages in the crankshafts and connecting rods
单项选择题 While troubleshooting a refrigeration system for low head pressure, liquid refrigerant flooding back from the evaporator is determined to be the causeIt may be necessary to （）.
单项选择题 Air trapped in the hydraulic fluid of a steering system should be indicated by （）.
单项选择题 Overgreasing of ball bearings installed on pumps will result in （）.