WebSQL is a SQL-like ___(71)___ language for extracting information from the web. Its capabilities for performing navigation of web ___(72)___ make it a useful tool for automating several web-related tasks that require the systematic processing of either all the links in a ___(73)___ , all the pages that can be reached from a given URL through ___(74)___ that match a pattern, or a combination of both. WebSQL also provides transparent access to index servers that can be queried via the Common ___(75)___ Interface.

A．query　　　　

B． transaction　

C．communication　

D．programming