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單項(xiàng)選擇題

The lower section of a piston is called the （）.

A.land
B.skirt
C.crown
D.plate

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單項(xiàng)選擇題

The diesel engine valve subjected to most severe conditions of service is the （）.

A.cylinder exhaust valve
B.air starting valve
C.air inlet valve
D.cylinder relief valve

單項(xiàng)選擇題

A piston in a four-stroke/cycle diesel engine makes four strokes during each （）.

A.crankshaft revolution
B.mechanical cycle of operation
C.period of two combustion cycles
D.cycle of two events

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