论文部分内容阅读
材料:两本相同的厚书、一张贺卡和一个大苹果(或其他重物)。做法:1.将两本相同的厚书平放在桌上,中间相隔的距离略短于贺卡的长度。
Material: Two identical thick books, a greeting card and a big apple (or other heavy object). Practice: 1. Place two identical thick books on the table with the distance slightly shorter than the length of the greeting card.