单项选择题
When you are firing a pyrotechnic distress signal，it should be aimed（）.
A.horizontally and directly abeam of your vessel B.at the vessel whose attention you want to attract C.into the wind D.at greater than 60 degrees above the horizon
单项选择题 When two vessels are in immediate danger of collision，the stand-on vessel must（）.
单项选择题 What is NOT a distress signal?（）
