单项选择题
A.power-driven vessel following a traffic lane
B.pilot vessel enroute to a pilot station
C.law enforcement vessel
D.All of the above
单项选择题 A sailing vessel is overtaking a power-driven vessel in a narrow channel，so as to pass on the power-driven vessel’s port side. The overtaken vessel will have to move to facilitate passage. The sailing vessel is the（）.
单项选择题 A power-driven vessel pushing aheador towing alongside displays navigation lights and（）.
单项选择题 A power-driven vessel leaving a quay or wharf must sound what signal? （）