A.litmus paperB.a combustible gas indicatorC.an oxygen ……

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

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

单项选择题According（）the report，the ship hit the wharf when berthing.

A.of
B.to
C.for
D.on

单项选择题A vessel showing a yellow light over a white light at night is a vessel（）.

A.engaged in piloting
B.towing astern
C.engaged in fishing
D.in distress

单项选择题A message warning of a tropical storm should be sent as a(n)（）.

A.routine message
B.urgent message
C.distress message
D.safety message