chromium
/ˈkrəumɪəm; `kromɪəm/ n[U]
metallic chemical element used in making alloys (such as stainless steel) and as a shiny protective coating on other metals 铬
chromium plating, eg on a car bumper 镀铬（如在汽车保险杠上）
chromium-plated 镀铬的. =>App 10 见附录10.