单项选择题
A marker pole，with a horseshoe buoy and a sea anchor attached，should be used to（）.
A.mark the position of a lost mooring B.determine your vessel's sideslip underway C.determine your speed through the water D.indicate location of a man overboard
单项选择题 （）the survivors known more of how to cope with cold water in the sinking of MV Titanic in 1912 countless lives（）.
