单项选择题
Ships equipped with Inmarsat SES send distress alerts both（）.
A.quick and good B.convenient and certain C.easily and simply D.important and difficult
单项选择题 In addition to communication equipment, the GMDSS will introduce requirements of SARTs and EPIRBs designed to improve the（）.
单项选择题 The GMDSS must combine all various subsystems, because（）.
单项选择题 Which Inmarsat system applies store-and-forward messaging?（）
