n.水准测量；平整；均匀化
动词level的现在分词.
He was busy leveling the ground and laying turves. 他正忙于平整土地铺草皮。
Extensive land leveling is often required because the topography must be smoother than for furrow irrigation. 由于畦灌的地形必须比沟灌的平坦，因此，常常需要大面积平整土地。
再平层
n.自动找平
