问题详情

Proper lubrication of the main bearing is more easily obtained in a single acting four-stroke/cycle diesel engine than in a single acting two-stroke/cycle diesel engine because ____.
A.bearing pressure in a four-strokecycle acting single diesel engine is continually reversed
B.bearing pressure in a two-strokecycle single acting diesel engine is continually reversed
C.the maximum bearing pressure is higher in a single acting two-stroke/cycle diesel engine
D.two-stoke/cycle diesel engines require more complicated lubrication piping请帮忙给出正确答案和分析，谢谢！