单项选择题
The common method of applying oil to the cylinder walls is by means of small pump assembled in units, known as （）.
A.mechanical lubricator B.lubrication function C.forced feed system D.bearing lubrication
单项选择题 The cleaned heated oil, after passing through the centrifuges, is to be pumped to a （）.
单项选择题 The cast iron guide-ways for （） are attached to the top section and seal off the crankcase.
单项选择题 The cast iron（）for the cross-head are attached to the top section and seal off the crankcase.
