If you ask me,will traditional classes be replaced by online classes?Well,my answer is definitely not. Because the quality of online classes teaching is completely lower than the traditional classes.Low classroom efficiency is the primary problem of online classes. First,teacher can't control students learning state. Second,techer' classroom management is greatly limited.The second problem is that the online classes is lack of after class tutoring. After class tutoring is a necessary supplement to the classroom. The online classes can not help students to digest knowledge.In my opinion,online classes are only suitable for short-term teaching. Because compared with traditional classes ,it has many limitations.If online classes are carried out for a long time ,there will be many problems for teachers and studengts.