单项选择题
A vessel may enter a traffic separation zone（）.
A.in an emergency B.to engage in fishing within the zone C.to cross the traffic separation scheme D.All of the above
单项选择题 A ship that，at any time，operates seaward of the outermost boundary of the territorial sea is required to prepare，submit，and maintain a(n)（）.
单项选择题 A safety shackle is identified by its（）.
单项选择题 A person who sees someone fall overboard should（）.
