WebSQL is a SQL-like (26) language for extracting information from the web. Its capabilities for performing navigation of web (27) make it a useful tool for automating several web-related tasks that require the systematic processing of either ail the links in a (28) , all the pages that can be reached from a given URL through (29) that match a’ pattern, or a combination of both. WebSQL also provides transparent access to index servers that can be queried via the Common (30) Interface.

（27）是（）

A.browsers

B.servers

C.hypertexts

D.clients

开发生命周期各个阶段正确的先后顺序是( )。

A．系统调查、系统分析、可行性研究、系统实施、系统设计、系统评价和维护

B．可行性研究、系统调查、系统分析、系统设计、系统实施、系统评价和维护

C．系统调查、可行性研究、系统分析、系统设计、系统实施、系统评价和维护

D．系统分析、系统调查、可行性研究、系统设计、系统实施、系统评价和维护