long cycle rust

例句：

1. 1. The old car's engine has started to rust.
   这辆旧车发动机开始生锈了。
2. 2. The metal surface is covered in a layer of rust.
   金属表面覆盖着一层锈。
3. 3. Rust can be caused by exposure to water and oxygen.
   锈可以由暴露于水和氧气引起。