rubble outerskin

例句：

1. 1. The outer layer of the skin is made up of dead cells.
   皮肤的最外层由死亡细胞组成。
2. 2. The outer space is vast and empty.
   外太空广阔而空旷。
3. 3. The outer wall of the building is covered in moss.
   这座大楼的外墙覆盖着苔藓。