论文部分内容阅读
可乐是我的最爱,我发现可乐瓶的底部都是向内凹陷的,这是为什么呢?A:其实,许多装有液体的瓶子或罐子底部都有凹陷
Coke is my favorite, and I found Coke bottle bottoms are inwardly concave, which is why? A: In fact, many bottled bottles or tanks have a hollow