预设和生成是精彩的课堂教学不可或缺的两个方面。过分强调预设和封闭,缺乏必要的开放和生成,课堂教学则变得机械、沉闷和程式化,缺乏生机和活力,使师生的生命力得不到充分发挥;单纯依靠开放则变得无序、失控和自由化,缺乏目标和计划,使师生生命力得不到高效发挥。因此,教师必 Presets and builds are two of the most important aspects of classroom instruction. Overemphasis on presupposition and closure, the lack of necessary opening up and generation, classroom teaching becomes mechanical, dull and stylized, lack of vitality and vitality, teachers and students can not give full play to the vitality; simply relying on the open become disorderly , Out of control and liberalization, lack of goals and plans, and ineffective vitality of teachers and students. Therefore, teachers must