VRML is a （71） for 3D multimedia and shared virtual worlds on the WWW. In comparison to HTML, VRML adds the next level of interaction, structured graphics, and extra（72） (z and time) to the presentation of documents. The applications of VRML are （73）, ranging from simple business graphics to entertaining WWW page graphics,manufacturing, scientific, entertainment, and educational applications, and 3D shared virtual worlds and communities.X3D is the name under which the development of VRML is continued. X3D is based on XML and is backwards （74） with VRML. Furthermore, it is componentized, profiled, and extensible, which makes it possible to use X3D in very different （75）, from high-end visualizations to lightweight applications.

A．scenarios

B．places

C．applications

D．programs

唐太宗被北方各族称为“天可汗”，表明______

A．唐太宗奉行民族平等、民族团结和民族繁荣的政策
B．唐朝实行开明的民族政策
C．唐太宗成为各少数民族共同的统治者
D．唐朝疆域辽阔