单项选择题
In NAVTEX service, VITAL warnings will（）by transmitting station.
A.be transmitted at once though the frequency is not clear B.be transmitted as soon as the frequency is cleared coordinately C.be transmitted at its scheduled transmissions D.be transmitted at next scheduled transmissions
单项选择题 In NAVTEX service, the subject indicate character B means（）.
单项选择题 NAVTEX transmissions have a designed range of about（）nautical miles.
单项选择题 The NAVTEX receiver can be mounted on（）.
