layer lattice

例句：

1. 1. The building has several layers of floors.
   这栋楼有好几层楼。
2. 2. She added a layer of paint to the wall.
   她在墙上加了一层油漆。
3. 3. The scientist used a microscope to observe the layers of the sample.
   科学家用显微镜观察样本的层次。