详细解释:(英国)皇家海军, 注册护士
【计】 新闻阅读程序
【医】 氡(86号元素)
英语解释：
名词 rn:
a radioactive gaseous element formed by the disintegration of radium; the heaviest of the inert gasses; occurs naturally (especially in areas over granite) and is considered a hazard to health同义词：radon, atomic number 86