As the fast speed of deveiopment in world, the knowledge storation of a peoele is updating continuly and our conception about the world is also changed rapidly. What is over a debate is that whether a teacher should be required to attend courses every five years to update their knowledge. From the my view point, I do not think this plan is that necessary based on the following reasons.First, how can we define and evaluate a good teacher?  Fresh knowleged may be one of them, but among the most important factors is other qualities, such as expressing ability, controling ability. These are all essential factors for a good teahcer,  Take my new oriental English teachers for instance. When attending their classes, it is definitely a process that you can enjoy instead of boring and tedious. At the same time, you can acquire so many useful knowlege. Since these teachers all have excellent expression ability, they can pass through the point to yoo with clear mind and expression. Moreover, they knowexactly how to control the whole class and stimulate students when they are tired with fuuny jokes. However, what they teahch the students remain the same for many years and students also get a good grade with these old knowledge.Another reason I want emphazise is that some kind of courses do not need to update the teachers' knowledge. The most dramatice examples are cousres like vebol and histroy. In history class, what teacher and students focus on is things happened in a long time ago, but not current affairs. Also, in most of the vebol class, teacher usually talk about great articles wirtten by famous writters, like shakespare, tuoersitia and so on. All these artiicles are all about the past liturature complishment. Apparently, these teachers do not need to update knowledge.In addtion, teacher can update knowledge via other ways like pay close attention to what had happened in his or her teahcing field. Moreover, five years a little too long to update. When teachers get these "new" knowledge, they may be even out of date already,Well, the benefit we can gain form updating cannot be left out though avordiance is reasonable. For example, teachers can correct what may mistake in the history immediately and receive new infornation which is essential for students. Indeed, course like luxury and fashion management do need to update information at every time.Clearly, teachers should not be required to update knowledge by attending classed since it is unnecessary in some kind of subjects and it is also not the key point in teaching process. Plus, teachers can get new knowledge via other route.