单项选择题
Every radio installation shall be clearly marked with the（）, the ship station identity and other codes as applicable for the use of the radio installation.
A.call sign B.port of register C.radio name D.signal label
单项选择题 A station in the mobile service the emissions of which are intended to facilitate search and rescue operations is（）.
单项选择题 （）process the distress signal from EPIRB to determine its position and identity.
单项选择题 The range of a MF coast station is normally（）nm.
