When any of the lessons already.Students have to practice the exercises within lessons.If students do not understand. The teacher must explain it correctly.It is necessary to have the time to learn each subject to no less than 2. 1 hour per lesson
When any lessons.The students have to do the exercises in class.If students do not understand, teachers have to get this right.Therefore, it is necessary to have time to study each of not less than 2 hours per 1 periods.