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單項選擇題

Deficient oxygen content inside a chain locker can be detected with（）.

A.litmus paper
B.a combustible gas indicator
C.an oxygen breathing apparatus
D.an oxygen indicator

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單項選擇題

Continuous sounding of a fog whistle by a vessel is a signal（）.

A.that the vessel is anchored
B.to request the draw span of a bridge to be opened
C.of distress
D.that the vessel is broken down and drifting

單項選擇題

Before entering the chain locker，you should（）.

A.have someone standing by
B.make sure there is sufficient air within the locker
C.de-energize the windlass
D.All of the above

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