directory assistance service

常见例句

Likewise for rating stories on Digg, voting on Yahoo Answers, or using Google's 411 service (see "How Can Directory Assistance Be Free?").
同样，通过在Digg或雅虎问答上的投票，或使用Google的411服务（参见“查号台服务为何能免费？”），也都是如此。
blog.sina.com.cn
This Recommendation gives an overview of methods and general principles to be followed in organizing an International Telephone Directory Assistance Service.
本建议对组织国际电话查号业务所遵循的方法和一般原则提出一个总的看法。
www.ptsn.net.cn
The service also offers free conference calling and directory assistance, perks that normally tack on extra dollars to the average phone bill.
语音服务还提供免费的会议呼叫、通讯录助理等功能，这些功能相当于在一般水平的电话账单基础上提供了额外的补贴。