单项选择题
What would most likely prevent a SART’s signal from being detected?（）
A.Signal absorption by the ionosphere B.Heavy sea swells C.The rescue personnel were monitoring the 10-cm radar D.The rescue personnel were monitoring the 3-cm radar
单项选择题 What is the primary purpose for Digital Selective Calling (DSC)?（）
单项选择题 What is the primary equipment for receiving MSI? （）
单项选择题 What is the MOST important thing you should do before transmitting on a marine radio? （）
