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單項(xiàng)選擇題

Wear occurring at the tips of the reduction gear teeth is usually the result of （）.

A.surface fatigue
B.fretting corrosion
C.heavy overloading
D.gear misalignment

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單項(xiàng)選擇題

The following preparations are essential for any （） of marine diesel engine before it may be started.

A.doing
B.make
C.turn
D.operating

單項(xiàng)選擇題

The diesel engine consumes considerably less fuel than the steam engine for equal output, （） enables a motor-ship to load more cargo.

A.why
B.which
C.in which
D.on which

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