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单选题
In four strokes engine, the cycle of events is completed in four strokes of （）.
A
the cylinder
B
the crankshaft
C
the piston
D
the cross-head
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单选题A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.A
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mechanical cycle of operationC
period of two combustion cyclesD
cycle of two events
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