近几年来,在中学化学教学中,广大化学教师常常在议论着这么一个问题,随着化学教学要求的不断提高,怎样提高化学教学质量?特别是怎样培养学生分析问题和解决问题的能力,这是一个大题目,当然要从各方面进行努力,但我们认为其中一个十分重要的环节是教师怎样进一步改进课堂教学,特别值得注意的是要合理设计每一节课的知识“阶梯”。这不仅使学生 In recent years, chemistry teachers in the middle school often discuss such a problem. With the continuous improvement of teaching requirements for chemistry, how to improve the quality of chemistry education, especially how to cultivate students’ ability to analyze problems and solve problems? It is a big problem, of course, we must work hard in all aspects, but we think that one of the most important aspects is how teachers can further improve classroom teaching. What is particularly noteworthy is to rationally design the “ladder” of knowledge for each lesson. This not only enables students