设计自制教具　解决教学难题田曼青时区和日界线是中学地理教材中的传统教学难点，这部分内容比较抽象，限于初中同学的知识基础、认识水平和思维能力，学生与教材之间的矛盾就显得较为突出，如果仅凭一块黑板、一枝粉笔、一张嘴巴讲到底，很容易把课上成一潭死水，毫无生... Designing self-made teaching aids to solve teaching problems Tian Manqing’s time zone and date line are the traditional teaching difficulties in middle school geography textbooks. This part is more abstract and limited to the knowledge base, understanding level and thinking ability of junior high school students. The contradiction between students and teaching materials seems to be relatively Prominently, if you just use a blackboard, a piece of chalk, and a mouth to tell the end, it’s easy to turn your class into a pool of stagnant water. There is no life...