单项选择题
What is the MOST important thing you should do before transmitting on a marine radio? （）
A.Ask for permission B.Record the time in your radio log C.Press the push to talk button three times D.Monitor the channel to insure that it is clear
单项选择题 What is a “Special Warning”? （）
单项选择题 What does a SART signal sound or look like?（）
单项选择题 The radiotelephone safety signal is（）.
