ａ .要明确用意。教师在备课时要依据大纲 ,吃透教材 ,明确实验在教学中的地位和作用。例如 ,初二物理《浮力》一节的用弹簧秤分别在空气和水中称同一物重而存在读数差的实验就是用来验证下沉物体也受到浮力。但有的教师在教学中却是先肯定物体受到了浮力 ,然后再做实验得出计 a. Be clear about intentions. When preparing lessons, teachers should follow the outline and thoroughly understand the teaching materials to clarify the role and role of the experiment in teaching. For example, the second experiment of physical buoyancy in the second grade of the “buoyancy” physics experiment using the spring scale to weigh the same object in air and water but with a poor reading is used to verify that the sinking object is also buoyant. However, some teachers first affirmed that objects were subject to buoyancy in their teaching.