category of trains

例句：

1. 1. The book is divided into several categories based on its content.
   这本书根据内容被分为几个类别。
2. 2. Different people have different preferences when it comes to selecting a category of goods.
   当选择商品类别时，不同的人有不同的偏好。
3. 3. This new product falls into the same category as the previous one.
   这款新产品与之前的产品属于同一类别。