单项选择题
The description Racon beside an illustration on a chart would mean a（）.
A.radar transponder beacon B.radar conspicuous beacon C.radar calibration beacon D.circular radiobeacon
单项选择题 The correct method of switching off a marine radar is to turn power switch to（）position first，then to（）position.
单项选择题 The common way to obtain your ship’s position is（）.
单项选择题 The closest point of approach (CPA) of a contact on a relative motion radar may be determined（）.
