rust of beet

例句：

1. 1. The old car's engine has a lot of rust on it.
   这辆旧汽车的引擎上有很多锈。
2. 2. The metal was so corroded that it could not be used for anything.
   金属被腐蚀得无法再使用。
3. 3. Rust is a natural substance that forms when iron oxidizes in the presence of moisture.
   锈是一种自然物质，当铁在潮湿的环境中氧化时形成。