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.

A.removed
B.altered
C.corrected
D.converted

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（）.

A.always be nearer to the equator
B.always be nearer to the elevated pole
C.be nearer to the pole in the Northern Hemisphere and nearer to the equator in the Southern Hemisphere
D.be nearer to the pole or the equator depending on the latitudes of the arrival and departure positions

单项选择题Buoys which only mark the left or right side of the channel will never exhibit a light with which characteristic? （）

A.Flashing
B.Quick flashing
C.Composite group flashing
D.Equal interval (isophase)

单项选择题Buoys which mark isolated dangers are painted with alternating（）.

A.red and black bands
B.green and black bands
C.red and white stripes
D.green and white bands

单项选择题Buoys which mark dredging areas are painted（）.

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