a directory of assistance执行局还建立了反恐怖主义委员会
DSA Directory Service Assistance目录服务助手
directory assistance position查号台
automated directory assistance自动转接系统
NDA National Directory Assistance全国工商名录助理
Telephone directory assistance电话号码查号台
directory assistance operator电话查号操作员
For English Directory Assistance英语查号服务
national directory assistance全国工商名录助理
N-UNCOUNT（不可数名词） Directory assistance is a service which you can telephone to find out someone's telephone number. 电话查号服务 [美国英语]
He dialled directory assistance.
他拨了查号台的电话。