这节课的教学目的是使学生了解菊科、十字花科的代表植物，理解各种的主要特征，从而加深理解植物的分类方法。课前教师把放大镜、解剖器、印好的观察实验表、花和果实的标本（放在不同的玻璃皿中）发给学生。发给第一大组的是向日葵、大白菜的花和果实；给第二大组的是菊花、 The purpose of this lesson is to enable students to understand the representative plants of Compositae and Cruciferae, and to understand the main characteristics of each species, so as to deepen the understanding of the classification of plants. Pre-class teachers distributed the magnifiers, dissectors, printed observatory tables, and specimens of flowers and fruits (in different glass dishes) to students. The first big group is the flowers and fruits of sunflower and Chinese cabbage; the second group is the chrysanthemum,