toll dialing trunk 长途拨号中继线

operator toll dialing system 话务员长途拨号制

nationwide toll dialing 全国长途拨号

subscriber toll dialing system 用户长途拨号制

toll dialing system [通信] 长途拨号系统

subscriber toll dialing 用户长途拨号

operator's toll dialing system 话务员长途拨号系统

toll dialing directory desk 长途查询台

toll dialing office 长途拨号局