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