单项选择题
A.most critical in a four-stroke cycle diesel engine
B.most critical in a two-stroke/cycle diesel engine
C.most critical in a four-stroke/cycle diesel engine if it is turbocharged
D.of equal importance in a two-stroke/cycle diesel engine as in a four-stroke/cycle diesel engine
单项选择题 If the piston groove drain holes for the oil control rings become clogged, which of the following is likely to occur?（）
单项选择题 Many cast iron pistons are designed with heat dams, which serve to （）
单项选择题 The adverse effects of burning high sulfur fuel can be compensated for by using a cylinder oil having sufficient（）