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（）.

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

单项选择题Buoys are marked with reflective material to assist in their detection by searchlight. Which statement is TRUE? （）

A.A safe-water buoy will display red and white vertical stripes of reflective material
B.All reflective material is white because it is the most visible at night
C.A special-purpose mark will display either red or green reflective material to agree with its shape
D.A preferred-channel buoy displays either red or green reflective material to agree with the top band of color

单项选择题Branford reef is（）.

A.a hard sand shoal marked with a light
B.completely submerged at all stages of the tide
C.surrounded by rocks awash at low water spring tides
D.a small，low，sandy islet surrounded by shoal water