Busy signal detected at remote site on callback.
在远程站点回拨时检测到了占线信号。
get a busy signal
从(听筒中)听到占线的信号声
percentage of sections having automatic signals to total route kilometres
装有自动信号区段线路占线路总里程百分率
Line judge,singal please.
司线员,请打信号。
The phone might be busy, or possibly the number is incorrect.
电话可能占线，或者号码或许不正确。
Sorry ! That number' s engaged.
对不起! 这个号码现在占线.
The number is engaged at the moment. Try again in five minutes.
这个号现在占线. 五分钟後再试试吧.
That tone means that the number is engaged.
那种声音表示该号电话占线.
The number being dialed was busy, or you may need to modify the number being dialed.
所拨打的号码占线，或者您需要更改拨打的号码。
her line is busy; receptionists' telephones are always engaged; the lavatory is in use; kept getting a busy signal.
她的电话忙；接待员的电话总是占线；厕所正在使用；持续接受忙碌的信号。
Cannot request exclusive semaphores at interrupt time.
无法在中断时请求独占的信号灯。
international time signals
国际无线电对时信号
a weak light, signal, sound
微弱的光线、 信号、 声音
Admiralty List of Radio Signals
《英版无线电信号表》
light-signal transfer characteristic
光信号转换特性曲线
equal signal system
等信号无线电导航系统
Interception of a radio transmission.
截听截取无线电信号
runway ecnterline lights system
跑道中心线信号灯系统