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