phrenotheca

例句：

1. 1. The old car was covered in a layer of phrenotheca.
   那辆旧车被一层铁锈覆盖。
2. 2. The metal door had been rusted open by the rain.
   金属门被雨水锈蚀而敞开。
3. 3. The old house needed a good cleaning to remove the phrenotheca from its walls.
   这所老房子需要好好打扫，以清除墙面的铁锈。