When making landfall at night，you can determine if a light is a major light or an offshore buoy by（）.

单项选择题When entering from seaward，a buoy displaying a single-flashing red light would indicate （）.

A.a junction with the preferred channel to the left
B.a sharp turn in the channel to the right
C.the starboard side of the channel
D.a wreck to be left on the vessel's port side

单项选择题When entering a channel from seaward，the numbers on buoys（）.

A.are the same as their Light List number
B.are marked in 6 inch figures with retroreflective material
C.increase with the even numbers to starboard
D.decrease with the odd numbers to starboard

单项选择题When approaching a preferred-channel buoy，the best channel is NOT indicated by the（）.

A.light characteristic
B.color of the uppermost band
C.shape of an unlighted buoy
D.color of the light

单项选择题When a buoy marks a channel bifurcation，the preferred channel is NOT indicated by（）.

A.the shape of an unlighted buoy
B.the light color of a lighted buoy
C.the color of the topmost band
D.whether the number is odd or even

单项选择题What is the major advantage of high altitude observations?（）

A.Errors due to unusual parallax are eliminated
B.The same body can be used for a fix from observations separated by several minutes
C.The declination is the only information needed from the almanac
D.The semidiameter correction of the sextant altitude is eliminated