立方体

例句：

1. 1. The cube is a simple shape that can be used to represent many different objects.
   这个立方体是一个简单形状，可以用来代表许多不同的物体。
2. 2. The cube has six sides and four faces.
   立方体有六条边和四个面。
3. 3. The cube is the smallest unit of measurement in three-dimensional space.
   立方体是三维空间中最小的测量单位。