直接长途拨号网络
direct distance dialing netwrok
Network
direct distance dialing
直接长途拨号
direct distance dialing
DDD
automatic long distance service
DIALING
direct distance
直接长途拨号电话
direct distance dialing telephone
Telephone
direct distance dialing
长途直拨
long-distance direct dialing
direct distarce dialing
DDD
国际直接拨号
international direct dialing
话务员长途拨号
ODD Operator Distance Dialing
话务员长途拨号制
operator toll dialing system
用户长途拨号
subscriber’s trunk dialling
subscriber toll dialing
STD
用户长途拨号制
subscriber toll dialing system