单项选择题
A.dockmaster B.dock captain C.lockmaster D.lock foreman
A vessel which is being assisted by an icebreaker would...
单项选择题A vessel which is being assisted by an icebreaker would display a flag hoist consisting of the code numeral 4 when the vessel（）.
A.speed begins to drop B.stops C.receives ice damage D.becomes icebound
A vessel which is being assisted by an icebreaker shoul...
单项选择题A vessel which is being assisted by an icebreaker should indicate that she is ready to cast off the towline by（）.
A.displaying code letter Y (Yankee) B.sounding five short blasts on his whistle C.displaying code numeral 5 D.sounding one prolonged blast on his whistle
A vessel the passage of which is not to be impeded（）to ...
单项选择题A vessel the passage of which is not to be impeded（）to comply with this Rule when the two vessels are approaching one another so as to involve risk of collision.
A.remains fully obliged B.has no obligation C.is not necessarily D.is exempted
