truff

例句：

1. 1.The old iron gate has a layer of rust on it.
   那把旧铁门上积了一层锈。
2. 2. The car's engine was badly damaged by the rust.
   汽车的引擎被锈严重损坏了。
3. 3.The metal surface is covered with a layer of rust.
   金属表面覆盖着一层锈。