【阿里巴巴大叔的话】大叔有两个好朋友,它们是一对乒乓球兄弟。它俩身高一样,体重一样,但在穿衣风格上迥异:弟弟喜欢活泼的黄色衣服,哥哥喜欢纯洁的白色衣服。它俩平时最喜欢一起去河里游泳了。今天它俩又去游泳了,不过这回它们去的可不是一条小河,而是大叔给它们特制的“游泳池”。这回发生了什么有趣的事呢?我们一起来看看吧!【乒乓球“游泳”研究】把空矿泉水瓶揭去外包装,从中间剪成两半,取下瓶盖。(如图2) [Alibaba uncle’s words] uncle has two good friends, they are a pair of table tennis brothers. They are the same in height and weight, but they are different in style: the younger brother likes the lively yellow clothes and the elder brother likes the pure white clothes. They usually like swimming together in the river. Today they both go swimming, but this time they are not going to a small river, but the uncle gave them a special “swimming pool.” What happened this interesting thing? Let us take a look at it! [Table Tennis “swim ” study] Unplug the empty mineral water bottle from the middle cut in half, remove the bottle cap. (Figure 2)