单项选择题
（）is used for providing homing signals from survival craft for detection by 9Ghzradar.
A.NAVETEX receiver B.Search and Rescue Transponder C.Emergency Position Indicating Radio Beacon D.Digital selective calling
单项选择题 （）is used for calling and replying,and for transmitting acknowleding and relaying distress alerts.
单项选择题 （）provides a paper trace of course steered by the vessel against time.
单项选择题 （）is a radio receiver with ablity to sense direction of the incoming radio waves.
