单项选择题
A vessel is（）when she is not at anchor，made fast to the shore，or aground.
A.underway B.making way C.dead in the water D.a power driven vessel
单项选择题 A structure，usually made of stone，or cement pilings，which extends from the bank at approximately right angles to the current is called a（）.
单项选择题 A spherical buoy may be（）.
单项选择题 A special purpose buoy shall be（）.
