A vessel may exhibit lights other than those prescribed by the Rules as long as the additional lights（）.

单项选择题A vessel engaged in trawling will show identification lights of（）.

A.a red light over a white light
B.a white light over a red light
C.a green light over a white light
D.two red lights in a vertical line

单项选择题A vessel engaged in mine clearance operations is called（）.

A.a vessel restricted in her ability to maneuver
B.a vessel not under command
C.a vessel constrained by her draught
D.a vessel not under way

单项选择题A vessel engaged in fishing shall keep out of the way of a vessel（）.

A.under sail
B.restricted in her ability to maneuver
C.crossing a channel
D.All of the above

单项选择题A vessel engaged in fishing must display a light in the direction of any gear that extends outward more than 150 meters. The color of this light is（）.

A.white
B.green
C.red
D.yellow

单项选择题A vessel engaged in fishing during the day would show（）.

A.one black ball
B.two cones with bases together
C.a cone，apex downward
D.two cones，apexes together