marginal fold

例句：

1. 1.The book's marginal fold has been torn.
   这本书的边缘褶皱被撕坏了。
2. 2.The scientist observed the animal's marginal fold during his research.
   科学家在研究期间观察了动物的边缘褶皱。
3. 3.The book's marginal fold is a unique feature that makes it stand out from other books.
   这本书的边缘褶皱是一个独特的特征，使它与其他书籍不同。