Each teacher has ways to convey knowledge of different environments in each class, it is different. Therefore, the teacher will use the debate has shown that the teacher is lazy.
Each teacher has to teach different. And an environment in which each class is different. Therefore, teachers will use the debate alone does not show that teachers are lazy.
Each teacher has to transfer knowledge are different. And the environment in the classroom, each is different. So that teachers will use the debate alone does not show that teacher is lazy.