单项选择题
The bore of each cylinder is formed in a liner which can be （） when worn out.
A.welded B.replaced C.drilled again D.bored
单项选择题 The bed-plate is secured in the longitudinal direction by means of bolts known as （）.
单项选择题 The bearing shells depend on the accuracy of （） to held them in a truly circular shape.
单项选择题 The bearing shell generally has （） for location and oil grooves round the center of its axial length.
