周五上课的时候,我给大家表演了一个小魔术——隔空捏气球,即不用手挨着气球就能将气球捏扁。我开始表演了,同学们各个屏住呼吸,瞪大了双眼,仔细地观察我的每个动作。随着我的手逐渐地做捏的动作,气球一点一点地变小了。这是怎么回事呢?同学们非常想知道其中的奥秘。于是,我决定带领大家一起做这个小实验,然后再为大家揭开其中的奥秘。实验器材:矿泉水瓶、气球、小刀。(如图1)实验方法:1.在矿泉水瓶的底 During the class on Friday, I performed a little magic for everyone – pinching the balloons across the air, that is, by squeezing the balloons without holding the balloons with their hands. I began to perform. The students held their breaths and widened their eyes. Each movement was carefully observed. As my hands gradually made pinching motions, the balloons became smaller and smaller. What is going on here? The students are very eager to know the mystery. So, I decided to lead everyone together to do this small experiment, and then open the mystery for everyone. Experimental equipment: mineral water bottles, balloons, and knives. (Figure 1) Experimental method: 1. In the bottom of a bottle of mineral water