cobordism class

例句：

1. 1. The study of cobordism is essential for understanding the physics of crystal growth.
   研究共形类对于理解晶体生长的物理至关重要。
2. 2.In cobordism, the shape of a material is determined by its surroundings.
   在共形类中，材料的形态由其周围环境决定。
3. 3.The cobordism class is used to describe the relationship between two objects in space.
   共形类用于描述两个物体在空间中的关系。