DOM is a platform- and language- （） API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents (currently, definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented （） . DOM is a （） -based API to documents, which requires the whole document to be represented in （） while processing it. A simpler alternative to DOM is the event-based SAX, which can be used to process very large （） documents that do not fit into the memory available for processing.

The document can be further processed and the results of that processing can be incorporated back into the presented （）.

A．text

B．image

C．page

D．graphic

按著录形式分类，检索工具可以分为（）、题录型检索工具、（）、（）。

A.目录型检索工具

B.摘要型

C.文摘型检索工具

D.索引型检索工具