单项选择题
A.general radio communication B.MSI C.improved distress and safety communication D.bridge-to-bridge communication
（）is the united nations agency responsible for the Radi...
单项选择题（）is the united nations agency responsible for the Radio Regulations among other things.
A.ITU B.IMO C.MSC D.WMO
The purpose of the GMDSS is to（）safety of life and prop...
单项选择题The purpose of the GMDSS is to（）safety of life and property at sea all over the world.
A.promote B.improve C.guarantee D.both A and B
The first communication satellite was used for the purp...
单项选择题The first communication satellite was used for the purpose of（）.
A.taking the place of the radio system B.introducing a new life-saving system C.saving the vessels in distress D.improving the communication on land
