单项选择题
A vessel not using a traffic separation scheme shall avoid it by as（）as is practicable.
A.wide a place B.wide a margin C.wide enough D.wide
单项选择题 Two short blasts of the whistle have all of the following meanings except（）.
单项选择题 Under international rules（）.
单项选择题 Under the rules, the term vessel includes（）.
