单项选择题 From your position you observe a rotating white and green light to the north. This light is most likely（）.

单项选择题 Fishing stake，the position of which frequently（），exist in the area covered by this chart.

单项选择题 Except for N-S courses，and E-W courses on the equator，a great circle track between two points，when compared to a rhumb line track between the same two points，will（）.