二次函数y=-x²-4x+2的顶点坐标、对称轴分别是（　　）

A．（-2，6），x=-2

B．（2，6），x=2

C．（2，6），x=-2

D．（-2，6），x=2

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.

which requires the whole document to be represented in （） while processing it.

A．document

B．processor

C．disc

D．memory