单选题The intake ports of a two-strike/cycle diesel engine are opened and closed by the action of the （）AcamshaftBpiston movementCexhaust valvesDvertical drive
单选题
The intake ports of a two-strike/cycle diesel engine are opened and closed by the action of the （）
A
camshaft
B
piston movement
C
exhaust valves
D
vertical drive
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