单项选择题
A 20-meter power-driven vessel pushing ahead or towing alongside will display（）.
A.a single white light forward B.two masthead lights in a vertical line C.two towing lights in a vertical line D.two all-round red lights where they can best be seen
单项选择题 A traffic separation zone is that part of a traffic separation scheme which（）.
单项选择题 A vessel using a traffic separation scheme shall（）.
单项选择题 In a traffic separation scheme，when joining a traffic lane from the side，a vessel shall do so（）.
