【英语时差8,16】不锈钢为什么不生锈？（上）

（单词翻译）

 Our modern world, with its skyscrapers¹, suspension bridges, and automobiles², relies heavily on steel. If you own an aging car however, you know firsthand that steel has one annoying problem: it rusts⁴. All steel, that is, except stainless⁵ steel. What keeps this remarkable⁶ material, used commonly in kitchen sinks and cookware, from rusting⁷? Steel’s main ingredient is iron. When steel rusts, its iron combines with oxygen and reverts⁸ to iron ore, the raw state from which it came. As this happens, the steel turns brown and begins to crumble⁹. There are many ways to protect steel from corrosion¹⁰. Steel is sometimes painted or greased, or coated with a metal that is less likely to rust³. Sometimes a metal that is MORE likely to rust is attached. Known as a sacrificial metal, this works by drawing the corrosion process away from the steel. For example, bars of zinc¹¹ are attached to the hulls¹³ of some ships. The zinc rusts heavily, but the steel hull¹² stays relatively¹⁴ safe.