radioactivesubstance

例句：

1. 1. The scientist detected a radioactive substance in the sample.
   科学家在样本中检测到了一种放射性物质。
2. 2.The radiation from the nuclear reactor is considered to be radioactive.
   核反应堆产生的辐射被认为是放射性的。
3. 3. The research team focused on identifying and isolating radioactive substances.
   研究小组专注于识别和分离放射性物质。