华东地区现行初中物理教材第二册第133页的“小实验”,是为演示火箭的原理和培养学生的学习兴趣而设置的,可惜它是不好的。为叙说方便,现将原文、原图照录如下: [小实验] 如图19-21所示,用细金属罐做成两个小“火箭”.通过“火箭”尾部小孔向体内注入适量的酒精,再将沾有酒精的棉花球捆扎在“火箭”的下面。当点燃酒精棉球后,就会看到 The “small experiment” on page 133 of Book 2 of the current junior middle school physics textbook in East China is designed to demonstrate the principles of the rocket and cultivate students’ interest in learning. Unfortunately, it is not good. For the convenience of narrative, now the original text and original image are recorded as follows: [Small experiment] As shown in Figure 19-21, two small rockets are made of thin metal cans. The right amount is injected into the body through the hole in the tail of the rocket. The alcohol was then tied with alcohol-impregnated cotton balls under the rocket. When you light the alcohol swab, you will see