单项选择题
A.NAVETEX receiver B.Search and Rescue Transponder C.Emergency Position Indicating Radio Beacon D.Digital selective calling
（）is used for providing homing signals from survival cr...
单项选择题（）is used for providing homing signals from survival craft for detection by 9Ghzradar.
（）is used for calling and replying,and for transmitting...
单项选择题（）is used for calling and replying,and for transmitting acknowleding and relaying distress alerts.
A.NAVETEX receiver B.Search and Rescue Transponder C.Emergency Position Indicating Radio Beacom D.Digital selective calling
（）provides a paper trace of course steered by the vesse...
单项选择题（）provides a paper trace of course steered by the vessel against time.
A.The echo sounder B.The radar C.The course recorder D.The direction finder
