一、课题的提出人类社会已跨入新千年,信息化成为世界经济和社会发展的大趋势,它正改变着人类社会的生产方式、生活方式和思维方式。特别是以具有开放、自由、无时空限制,且能把文字、图形、声音、动画和其他多媒体技术融合起来虚拟现实环境等特征的互联网为代表 I. The proposal of the topic The human society has entered the new millennium. Informationization has become the major trend of world economic and social development. It is changing the production methods, lifestyles, and ways of thinking of human society. In particular, it is represented by the Internet, which is open, free, and free of space-time constraints, and that can integrate characters, graphics, sound, animation, and other multimedia technologies into a virtual reality environment.