hard sphere

例句：

1. 1. The hard spheres are made of carbon and silicon.
   这些硬球体由碳和硅制成。
2. 2.The hard spheres attract each other due to their strong electrostatic forces.
   由于强烈的静电作用，硬球体相互吸引。
3. 3. The hard spheres in the liquid are arranged in a regular pattern.
   液体中的硬球体以规律的排列方式存在。