单项选择题

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.

A.hypertext
B.page
C.protocol
D.operation