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
单项选择题 The purpose of the GMDSS is to（）safety of life and property at sea all over the world.
单项选择题 The first communication satellite was used for the purpose of（）.
单项选择题 A sailor on board（）from appendicitis and required operation immediately.
