单项选择题
When you are firing a pyrotechnic distress signal，it should be aimed at（）.
A.straight overhead B.at the vessel whose attention you are trying to get C.into the wind D.about 60 degrees above the horizon
单项选择题 When should distress flares and rockets be used? （）
单项选择题 When sending a DSC call，the vessel’s（）.
单项选择题 When can routine communications be resumed when radio silence has been imposed?（）
