单项选择题
A.litmus paper B.a combustible gas indicator C.an oxygen breathing apparatus D.an oxygen indicator
Continuous sounding of a fog whistle by a vessel is a s...
单项选择题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
Before entering the chain locker，you should（）.A.have so...
单项选择题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
According（）the report，the ship hit the wharf when berth...
单项选择题According（）the report，the ship hit the wharf when berthing.
A.of B.to C.for D.on
