“加油，加油……”教室里两位同学正在奋力地拉两本书呢，可是这两本书似有魔力一样，不管两位同学怎么拉也拉不开，正犯愁呢！原来这节课，老师带着我们做了个小实验，叫做“难舍难分的书。”
Come on, come on... "The two classmates in the classroom were struggling to pull two books, but these two books seemed to have magic power. No matter how hard they pulled them, they couldn't open them and were worried! Originally, in this class, the teacher led us to do a small experiment called "Books that are hard to part with
老师先跟我们说了实验的步骤，先找两本厚厚的书，再把两本书一页一页地交叠起来，然后找两名或者更多名同学与这两本书比“力气”。作文 WwW.ZuOwENbA.NeT
The teacher first explained the steps of the experiment to us. First, find two thick books, then overlap them page by page, and then compare the strength of two or more students with these two books.
我们都跃跃欲试，争先恐后地举起手来。罗老师点了李同学和张同学上去，张同学自信满满地走上讲台，李同学却是眉头紧锁，脸真是涨得像一个红透的大红苹果。
We are all eager to try, eagerly raising our hands. Teacher Luo ordered Li and Zhang to go up. Zhang confidently walked onto the podium, while Li furrowed his brow and his face swelled like a bright red apple.
只见双方正紧紧地握住两本书的两侧，两人似在跟书“斗”，比比谁的力气大，谁也不愿看到自己还不如书的力气大呀！可是张同学和李同学已经用了九牛二虎之力，书却纹丝不动的。既然两个人都拉不动，老师就将我们分成了二个大组，每组六个人，我们像拔河一样都使出了浑身的劲儿，但还是拉不开书。我们很沮丧，想不明白为什么十二个人的力气还不如两本书？
I saw both sides tightly gripping the sides of the two books, as if they were "fighting" against each other, comparing whose strength was stronger, and neither of them wanted to see that they were not as strong as the books themselves! But Zhang and Li have already used their full strength, but the book remains unchanged. Since neither of us could move, the teacher divided us into two large groups of six people each. We exerted all our strength like a tug of war, but still couldn't open the book. We are very frustrated and cannot understand why the strength of twelve people is not as good as two books?
老师给我们讲解说：“这是摩擦力在作怪，书的纸面并不是平滑的，中间有许多细小的凹凸面，虽然它们只是轻轻的夹叠在一起，但是书页与书页之间会产生摩擦力，书页重叠得越多产生的摩擦力就越大，所以拉不开……”
The teacher explained to us, "This is friction causing trouble. The paper surface of the book is not smooth, with many small bumps and depressions in the middle. Although they are only gently stacked together, friction will be generated between the pages of the book. The more pages overlap, the greater the friction force generated, so it cannot be pulled open
我觉得这节课不仅好玩，还可以学到有趣的科学知识，真是一举两得呢！
I think this class is not only fun, but you can also learn interesting scientific knowledge. It's really killing two birds with one stone!