Well it's fairly simple, given enough time all radioactive elements would decay in to non radioactive forms.

好吧，这很简单，只要有足够的时间， 所有放射性元素都会衰变成非放射性形式。

Well it's fairly simple, given enough time all radioactive elements would decay in to non radioactive forms. Even ultra stable bismuth, with it's half life longer than the age of the universe.

好吧，这很简单，只要有足够的时间，所有放射性元素都会衰变成非放射性形式。 即使是超稳定的铋， 它的半衰期也比宇宙年龄还长。