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