短語詞組短語busy back signal 忙回信號(hào);占線信號(hào)busy flash signal 占線信號(hào);占線閃光信號(hào)busy tone signal 占線信號(hào);忙音信號(hào)subscriber -busy signal 用戶忙信號(hào);用戶占線信號(hào)busy -flash signal 占線閃光信號(hào)busy signal system 明顯損失制busy signal generator 忙音發(fā)生器group busy signal 群占線信號(hào)audible busy signal 音響占線信號(hào);可聞忙音訊號(hào);忙音信號(hào) 返回 busy signal