“月相变化及其成因”虽不是教学重点，但是教学难点。我根据小学自然课本第五册（“人教版”1989年第二版）P49的插图“月亮圆缺变化示意图”制成立体模型（图l）。1制作方法1．月球制作月球及托架如图2-（1）所示，由三部分构成：托架板；左端为平衡块；右端为月球模型组件。 “Moon phase change and its causes” is not the focus of teaching, but teaching difficulties. I made a three-dimensional model based on the illustration “Change of the Moon” in P49, Volume 5 of the Natural Science Textbook of Primary School (PEP 1989, 2nd Edition) (Figure 1). 1 production methods 1. Lunar production of the moon and the bracket as shown in Figure 2- (1) shows, consists of three parts: bracket plate; the left end of the balance block; the right end of the moon model components.