an internationally recognized distress signal in radio code
例句
用作名词(n.)
The ship is sending out an SOS signal.这条船正发出呼救信号。
They said no such call was logged on the SOS channel, but other radio traffic records were still being investigated.他们说，在求救频道中并没有这样的呼救纪录，不过其他的无线电通报纪录仍在调查中。
