单选题During the power stroke of a four-stroke/cycle diesel engine, most of the side thrust of a trunk-type piston is absorbed by the（）Apiston skirtBpinionCcrossheadDcompression rings
单选题
During the power stroke of a four-stroke/cycle diesel engine, most of the side thrust of a trunk-type piston is absorbed by the（）
A
piston skirt
B
pinion
C
crosshead
D
compression rings
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