放射铁

例句：

1. 1. Radium is arare and powerful radioactive element.
   镭是一种稀有且强大的放射性元素。
2. 2. Theradium in themine was discovered by accident.
   矿中的镭是偶然发现的。
3. 3. Radiumhas been used in medical treatments for manyyears.
   多年来，镭在医疗治疗中被使用。