唯物辩证法告诉我们:在一切活动中,都必须遵循一条适度的原则。课堂教学更是这样,更应该注意掌握量的分寸,“过”与“不及”都是课堂教学的大忌,都会直接影响课堂教学的效果。多　与　少多与少是相对的,因为听课者原有的基础现状各不相同,他们接受、理解所学知识的能力有高有低 Materialist dialectics tells us: In all activities, we must follow a moderate principle. Classroom teaching is more like this, more attention should be paid to grasping the measure of quantity. “Over” and “not” are all taboos in classroom teaching and will directly affect the effect of classroom teaching. More and less are relative, because the current status of lecturers varies, and their ability to accept and understand what they learn is high or low.