Why is the dancing teacher so bad?

First of all, it may be because of the dancing Mr. Du because the technology is not skillful caused by the general dance which is a very difficult action, is the need to go through a long time of training and drilling, in order to jump more perfect, and secondly, it may also be because of the reason of not serious, may be at this time the heart is very complicated, so it will lead to jump so bad.