“背斜成谷,向斜成山的原因”是高中地理教学的难点之一。为解决这一难点,多数教师通常采用的教学过程如图1所示。根据以上分析可知,“背斜顶部受张力易被侵蚀,向斜槽部受挤压力不易被侵蚀”是学生理解的难点。为了解决这一难点,笔者课上演示了实验一。一、实验一[实验材料]木条。[实验过程]教师握住木条的两端,慢慢用力使木条向上拱起,学生观察木条弯曲处顶部的变化,如图2 “Anticline into a valley, the reason why the mountain is oblique” is one of the difficulties of high school geography teaching. To solve this difficulty, most teachers usually use the teaching process shown in Figure 1. According to the above analysis, we can see that “the top of the anticline is easy to be eroded by the tension and the crushing pressure to the chute portion is not easy to be eroded” is a difficult point for students to understand. In order to solve this difficulty, I demonstrate a class experiment. First, a test [experimental materials] wood. [Experimental process] teachers hold both ends of the wood, and slowly force the wood arch upward, the students observed changes in the top of the wood bending, as shown in Figure 2