1. Too little syntax. According to the above, you won't say anything after reading one or two volumes. Even if all five volumes have been written, there is still a lot of grammar to be said.
2. Not practical, there is no CD and MP3, and the supporting recording is only tape, which is very inconvenient.
There is no text to read on the tape, and even the pronunciation can't be heard.
This text is not suitable for reciting.
Of course, this textbook also has some advantages, such as relatively new content, many pictures, exquisite printing and so on.
Ou Feng's teachers also thought about compiling their own textbooks, but without the support of the school, Ou Feng mainly enrolled students through media and advertising.