If you suddenly observe technetium in a sun-like star, you can be sure that somebody has put this element in the atmosphere, because in a natural way it is impossible to do this.
如果你突然发现有锝元素存在于 一个类太阳恒星中, 你可以肯定是有人将这种元素放进了 这个大气层。 因为在自然界中不可能发生.