graded surface

例句：

1. 1. The new building has a graded surface that is easy to clean.
   这座新建筑有一个易于清洁的分级表面。
2. 2.The engineer graded the surface of the road before it was paved.
   工程师在铺设道路之前对路面进行了分级处理。
3. 3. The construction crew used a graded surface to level the ground for the next phase of work.
   施工队使用分级表面平整地面，为下一阶段的工作做准备。