变电 站电 气主接线 是指变电 站的变压 器、输电线 路怎样 与电 力系统 相连 接，从而完成输 配电 任务 。变电 站的主接线 是电 力系统 接线组 成中一个重要组 成部分Lesson Plan Presentationtask-based teaching model 1. Analysis of teaching materials and students: Materials: PEP Go for it! Unit 7 we are having an English class. Students: Grade 7, Junior middle School2. Lesson type:grammar3. Teaching methodThe structure of present continuous timeThe way of changing form and different sentence patterns of present continuous time 4. Focal point and difficult point:变电 站电 气主接线 是
