An orange flag showing a black circle and square is a（）.

单项选择题An airplane wants a vessel to change course and proceed towards a vessel in distress. The actions of the aircraft to convey this message will NOT include（）.

A.circling the vessel at least once
B.heading in the direction of the distress location
C.flashing the navigation lights on and off
D.crossing ahead and rocking the wings

单项选择题ALL PASSENGERS OF DECK NO.2 ARE REQUESTED TO FOLLOW THE CREW MEMBERS WHO WILL ESCORT YOU TO YOUR ASSEMBLY STATIONS. From this sentence you can concluded that the vessel is in（）.

A.immediate danger to collide with another vessel
B.a situation in which more passengers will embark on board
C.berth and ready to disembark her passengers
D.distress

单项选择题All of the following are distress signals under the Rules EXCEPT（）.

A.International Code Signal AA
B.orange-colored smoke
C.red flares
D.the repeated raising and lowering of outstretched arms

单项选择题All of the following are distress signals EXCEPT（）.

A.the continuous sounding of any fog signal apparatus
B.giving five or more short and rapid blasts of the whistle
C.firing a gun at intervals of about a minute
D.a barrel with burning oil in it，on deck

单项选择题After putting on a self-contained breathing apparatus，you open the air supply and hear a continuous ringing of a bell. What does this mean?（）.

A.The unit is working properly
B.The face mask is not sealed properly
C.The air bottle needs to be refilled
D.The air supply hose has a leak