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