It's element number one of the possession charge is that they have to knowingly possess.

占有罪的第一要素是他们必须在知情的情况下占有。

As a result technetium, element number 43, and promethium, 61, are always radioactive (and are not found naturally in detectable quantities).

锝（43号元素）和钷（61号元素）都是放射性的，并且在自然中的存在数量无法侦测。

Ok so cerium, element number 58, has some bizarre uses, would you

好的，元素编号 58 的铈有一些奇怪的用途， 你会吗？