單項選擇題

why do some stations keep silence?（）

A.Because they are not engaged in the distress traffic
B.they will affect the transmission of the distress traffic
C.The powers of these stations are very weak
D.They are not in charge of search and rescue

你可能感興趣的試題

單項選擇題

What channel is general communication used?（）

A.any appropriate channel except public communication
B.any appropriate channel except for public communications
C.any appropriate channel besides public communication
D.any appropriate channel beside public communication

單項選擇題

What’s the advantage when using the satellites?（）

A.The message can be directed to the desired location
B.The message can follow the earth’s curvature
C.The quality of message can not be affected by climatic
D.The range of the message extend and the quality of reception is improved

无码高清视频|成人自拍视频|欧美成人午夜无码A片秀色直播|草美女视频网站|美女被操网站在线观看

why do some stations keep silence?（）

你可能感興趣的試題

What channel is general communication used?（）

What’s the advantage when using the satellites?（）