radioactive substance的用法和样例：
例句
- The radioactive substance can kill the nervous cells in the brain.
这种放射性物质会杀死大脑的神经细胞。 - Because of this radiation they said the substance was radioactive.
由于这种辐射性现象，他们把该种物质称为放射性物质。 - In the deep mantle the highest possible concentration of radioactive materials is limited by the condition demanding temperatures below the melting point.
在地幔深部，放射物质最高的可能浓度受溶点以下的温度条件所限制。
