单项选择题
When engaged on international voyages, ships of 1600 tons gross tonnage and upwards shall be fitted with a（）.
A.radio direction-finding apparatus B.DSC C.NAVTEX D.EPIRB
单项选择题 The maritime access code of telephone mode in INMARSAT-A terminal for the AOR(W) is（）.
单项选择题 In Inmarsat-A, “Priority 0” means（）communication.
单项选择题 The maritime access code for the IOR is（）in INMARSAT-A Telex Service.
