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 All of the following are distress signals under the Rules EXCEPT（）.
单项选择题 What is NOT a distress signal?（）.
单项选择题 What would NOT be a distress signal?（）.
