“先学后教”正是新课程教学理念的体现.物理上的“先学”形式多种多样,学生看书、练习、观察、实验等都是学的过程;“后教”是让会的学生教不会的学生,教的内容是学生自学过程中遇到的困难,急需解决的问题.一句话,在整个教学过程中,规律是由学生发现的,结论是由学生得出的,方法也是由学生找到的,即全过程让学生学,教师起了一个“引导者”和“指导者”的作用. “The first to teach ” is the embodiment of the new curriculum teaching philosophy.Physical “pre-school ” a variety of forms, students reading, practice, observation, experiment and so on are the learning process; “Is to let students will not teach students, teaching content is the difficulties encountered in the process of self-study, the urgent need to solve the problem.In short, throughout the teaching process, the law is found by the students, the conclusion is from Students come to the method is also found by the students, that is, the whole process for students to learn, the teacher played a ”leader “ and ”mentor " role.