单项选择题
A report of casualty to a mobile offshore drilling unit must be made in writing to which office? （）
A.Commandant of the Coast Guard B.Owner of the unit C.Nearest Coast Guard Marine Safety Office D.Captain of the nearest port
单项选择题 A red triangular daymark marks （）.
单项选择题 A rapid rise or fall of the barometer indicates（）.
单项选择题 A radar range to a small，charted object such as a light will provide a line of position in which form? （）
