g model, studying-assisting model, collaborate learning model, apprentice role model and content produce model. In the paper every model is elaborated respectively.
5. The developing trend of web courses
The characters of flexible, open and resources-based of web course make it potent in continuing education, quality education and professional education. Moreover, it could offer open opportunity for various professional personnel, which satisfy their different needs. There are three trends for web courses development. In the first place, resources on web would become rich more and more, the services on web would become multiple more and more, we could search for everything we need or learning material on web quickly; secondly, the center of web courses designing would shift from contents to learning environments, we have to integrate technology to courses, connecting the specific characters of web (resources sharing, mutual communication); finally, I am sure that, in the future, the design and development of web courses would be more advanced on technology application. At present, there appear some web courses tool platforms (e.g. WebCT), which make web courses convenient not only for designing and developing, but also for studying, which pushes web courses stride forward and becomes a natural trend.