You may see iron and oxygen in the red dust and clay of the road, in the red brick of houses, in many red paints, in red autumn leaves, and in the red cheeks of a healthy child.

• 路上的红色尘土和黏土里、房屋的红砖里。许多种红色涂料里、秋天的红叶里、甚至在健康的儿童那红润的脸蛋儿上，你都可以感受到铁和氧元素。