氡

例句：

1. 1. Radon is a naturally occurring radioactive gas that can be harmful to humans.
   氡是一种自然发生的放射性气体，对人类有害。
2. 2.The house was evacuated because of the high levels of radon in the area.
   由于该地区高浓度的氡，房屋被疏散了。
3. 3.Radon testing is important for detecting and controlling the risk of lung cancer associated with exposure to this gas.
   进行氡检测对于发现和控制与暴露于这种气体相关的肺癌风险至关重要。