But spent uranium fuel can also contain plutonium isotopes .

但乏铀燃料中也会含有钚同位素。

But isotopes can do more .

但是同位素的用处更多。

Rhenium isotopes are used to treat liver cancer .

铼的同位素被运用于肝癌的治疗。

Isotopes can even indicate the order in which the planets formed .

对同位素的考察甚至可以指出行星形成的次序。

Nevertheless , other isotopes suggest a supernova did go off just as the solar nebula was forming .

尽管如此，对其他同位素的观察表明，太阳系星云形成时确有一次超新星爆发。