单项选择题
A.The safety of navigation or important meteorological warnings
B.The safety of a vessel or a person is in jeopardy
C.A vessel in need of immediate assistance
D.A coast station traffic list
单项选择题 What publications should a GMDSS Operator consult regarding the proper set-up and operation of vessel equipment（）.
单项选择题 The data travels from the（）to the INMARSAT Network Coordination Station（NCS）and then down to the SES’s on ships at sea.
单项选择题 The（）provides the link between the Space Segment and the land-based National/International fixed communications networks.