(课前,老师组织学生开展组装“电路检测器”比赛。)一、直接揭题,了解学生的已有认知师:知道今天李老师要和大家研究什么吗?生:让我们研究导体和绝缘体。师:(板书课题)根据你的经验,什么叫导体?生:易导电的物质叫导体。师:那什么叫绝缘体呢?生:我觉得绝缘体是不导电的。生:不是不导电,而是很难导电,或者是导电的性能很差。 (Before class, the teacher organizes the students to assemble the circuit detector.) First, to directly expose the students’ existing cognition teachers: Do you know what Teacher Li wants to study with you today? Health: Let’s study Conductor and insulator. Teacher: (blackboard topic) According to your experience, what is conductor? Health: easily conductive material called conductor. Teacher: What is insulation? Health: I think insulation is non-conductive. Health: not not conductive, but difficult to conductive, or conductive poor performance.