单项选择题
EGC is a（）part of INMARSAT-C.
A.component B.supportable C.combined D.complimentary
单项选择题 Distress signal are always stored in the memory so as to start（）.
单项选择题 Which Inmarsat system applies store-and-forward messaging?（）
单项选择题 （）are operated as a secondary method of alerting in the GMDSS.
