单项选择题
A.lubricating oil
B.compressed air
C.cooling water
D.sealing ring
单项选择题 The joint face between the cylinder cover and the liner is arranged ()the combustion process as possible.
单项选择题 The interface between the liquid seal (water) and the oil should be positioned () possible to the bowl periphery.
单项选择题 The inner part of the condenser should be cleaned with ().