单选题 WebSQL is a SQL-like (76) language for extracting information from the web. Its capabilities for performing navigation of web (77) make it a useful tool for automating several web-related tasks that require the systematic processing of either ail the finks in a (78) , all the pages that can be reached from a given URL through (79) that match a pattern, or a combination of both. WebSQL also provides transparent access to index servers that can be queried via the Common (80) Interface.