单项选择题
A vessel towing astern in an operation which severely restricts the towing vessel and her tow in their ability to change course shall，when making way，exhibit（）.
A.the masthead lights for a towing vessel B.the lights for a vessel restricted in its ability to maneuver C.sidelights，stern light and towing light D.All of the above
单项选择题 A vessel towing a barge astern would show，at the stern（）.
单项选择题 A vessel sighting a northern right whale dead ahead should（）.
单项选择题 A vessel showing a rigid replica of the International Code flag “A” is engaged in（）.
