If most of their dopamine receptors were free, on the other hand, the radioactivesubstance would bind to them.
从另一方面来说，如果大多数的巴多胺感受器处于空闲，那么放射性物质将会继续依附其上。
2
Alexander Litvinenko, a renegade Russian security officer living in London, was killed by poisoning with polonium, a rare radioactivesubstance, in 2006.
居住在伦敦的叛逃俄罗斯安全情报官员亚历山大·利特维年科在2006年被一种稀有辐射性物质钚投毒暗杀。
3
Or a radioactivesubstance may be disintegrating at a known rate and we may be required to determine the amount of material present after a given time.