单项选择题
The GMDSS defines four sea area based on the（）.
A.location and capacity of the facilities located on board ships B.Position and type of a sincere sintion C.Capacity and location of shore based communication facilities D.Position and capacity of mobile communication stations
单项选择题 The position if the IOR satellite in the INMARSAT system is（）above the equator.
单项选择题 There are some back-up satellites in the event of failure. If the operational satellite is out of work,（）.
单项选择题 The satellites over the major ocean regions cover the globe（）.
