单项选择题
International Navtex service is（）.
A.a terrestrial MF system B.a satellite communication system C.a land HF radio system D.a coastal VHF system
单项选择题 What language does International NAVTEX use?（）
单项选择题 When the power of SART is on, it will（）.
单项选择题 Distress traffic（）all messages relating to the immediate assistance required by the ship in distress, including search and rescue communications and signals for locating.
