单项选择题
A.the weather is always terrible
B.the condition there is complicated
C.the signals are too strong
D.their SES may recive the signals from unwanted satellite
单项选择题 The coordinated broadcast and automated reception of MSI via the INMARSAT EGC system using English to meet the requirements of the SOLAS Convention:（）.
单项选择题 All NAVTEX messages（）owing to their nature of importance.
单项选择题 The difference between international and national Navtex Service is limited to（）.