去年,在我县山区的一所中学里专门观看了一下初三学生做实验的情况,实验的内容是《初中物理》第二册第四章第七节“组成串联电路和并联电路”.由于该校实验室里没有学生电源,故用于电池供电.电池是老师在课前才买回来的,但是还不到下课的时间就有两个小 Last year, in a middle school in the county of our county, I watched specifically what the junior high school students did in their experiments. The contents of the experiment were “Physics in Junior High School” Book 2, Chapter 7, Section 7, “Forming Series Circuits and Parallel Circuits.” Since there is no student power supply in the school’s laboratory, it is used for battery power. The battery was bought by the teacher before class, but there are two small hours before class.