1·Helium is the by product of millennia of radioactive decay from the elements thorium and uranium.
氦是钍和铀元素数千年放射性衰变的副产品。
2·No, she told me, because thorium reactors are not a proven technology.
她告诉我她不支持，因为钍反应堆不是一种被证明可靠的科技。
3·Unlike most supernovae, this one spewed lots of elements far heavier than iron, including radioactive thorium and uranium.
这颗晕星不同于大多数超新星，它吐出的许多元素比铁还重，其中包括放射性钍和铀。
4·They had been interested in thorium — a radioactive element that can fuel nuclear reactors but not be processed into weapons.
他们当时对一种放射性元素钍很感兴趣，这种元素能驱动核反应堆，却不能制造生产成武器。
5·In this case the geologists drilled into the stalagmites and estimated their age from the way that uranium decays into an isotope of thorium.
地质学家在石笋上钻孔，使用铀衰变成钍的同位素的方法确定它们的年龄。