planeness

例句：

1. 1. The car's dashboard is very flatness.
   汽车的仪表盘非常平面。
2. 2. The table is too flatness for my needs.
   这张桌子对我来说太平面了。
3. 3.The engineer measured the flatness of the surface to ensure it was level.
   工程师测量了表面平面度以确保其水平。