单项选择题
A.the weather over there is always terrible
B.the condition there is complicated
C.the signals are too strong
D.their SES may receive the signals from unwanted satellite
单项选择题 The quality of EGC messages is（）affected by the position of the ship, the time of reception and climatic conditions.
单项选择题 The identification character of each Navtex station is regarded as（）to the messages.
单项选择题 Exchange of answerbacks act s a confirmation that the messages（）at the destination.