A spherical buoy may be（）.

Buoys which mark dredging areas are painted（）.

Branford reef is（）.

A yellow buoy may mark a(n)（）.

A plane that cuts the Earth’s surface and passes through the poles will always form（）.

A structure，usually made of stone，or cement pilings，which extends from the bank at approximately right angles to the current is called a（）.

Fishing stake，the position of which frequently（），exist in the area covered by this chart.

A rock and sand structure extending from the bank of the river toward the channel is known as a（）.

A special purpose buoy shall be（）.

A white buoy with an orange rectangle on it displays（）.