An orange and white buoy with a rectangle on it displays（）.

单项选择题An orange and white buoy marking an area where operating restrictions are in effect will be marked with which symbol? （）

A.Open-faced diamond
B.Diamond with a cross
C.Circle
D.Rectangle

单项选择题An orange and white buoy marking a danger area will have what symbol on it?（）

A.Open-faced diamond
B.Diamond with a cross
C.Circle
D.Square

单项选择题An orange and white buoy indicating a vessel-exclusion area will be marked with what symbol? （）

A.Open-faced diamond
B.Diamond with a cross
C.Circle
D.Square

单项选择题A yellow buoy may mark a(n)（）.

A.wreck
B.shoal area
C.anchorage area
D.middle ground

单项选择题A yellow buoy may exhibit a(n)（）.

A.fixed red light
B.flashing light
C.white light
D.occulting light