[单选题]NAVTEX transmitter identification character B3 is a single unique letter that is allocated to each Navtex_______
[单选题]Although satellites will play an important role in the GMDSS, they will not completely replace the _________.
[单选题]________, the SART automatically emits response signals to indicate survivors’ position on the radar display.
[单选题]A retangular area is described in degrees of latitude and longitude from the latitude and longitude of the southwest corner of ____.
[单选题]In GMDSS, MSI broadcasts will be made on two _______ which provide near continuous automated reception on board ships.
[单选题]It is a feature of the satellite communications that reception is not generally affected by ____________
[单选题]If the beacon is mounted at a wrong palace, it may ___by sea water chemicals exhaust and vibrations.