《自然》第十二册第六课彩虹的秘密，利用三棱镜的色散作用来指导学生认识阳光是由七种色光组成。此实验除了用三棱镜外，我自制了类似三棱镜作用的学具来满足本课实验的需要。ａ．材料：一个直径３５ｃｍ，深１２ｃｍ的脸盆（不能用水槽）；小镜子；纸屏；水。ｂ．演示方法： The 12th chapter of nature "The secret of the rainbow, the use of prism dispersion to guide students to understand the sun is composed of seven kinds of color light. In addition to using this prism experiment, I made a self-made prism-like learning tools to meet the needs of this lesson experiment. a. Material: a basin of 35 cm in diameter and 12 cm in depth (can not use sink); small mirror; paper screen; water. b. Demo method: