教学是多边活动,也是多向传递活动。学生是主体,是教学中最活跃的动态要素,是教学质量水平的最终体现者。在全部教学过程中,预设学生活动环节要最多；在每一个学习活动中,预设学生参与的时间要最多；在学生的参与过程中,预设学生积极思考的时间要最多。如“通过实例感受——观察实例认识——探索基本规律”设置挑战性的问 Teaching is multilateral activities, but also multi-pass activities. Students are the main body, which is the most active dynamic element in teaching and the ultimate embodiment of teaching quality. In the whole teaching process, it is presupposed that students have the most activities. In each learning activity, the default time for students to participate is the largest. During the process of student participation, the default time for students to think positively is the most. Such as “experience through examples - observe the understanding of the case - to explore the basic law” to set challenging questions