在太阳和行星形成之前，所有元素周期表上的化学元素在太阳系的原始尘埃中四处漂浮着。

Before the formation of the sun and planets, all the chemical elements found on the periodic table were floating around in the primordial dust of the Solar System.

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So, remember when you're looking at your periodic table, don't forget about the lanthanides, sometimes they come into play.

因此，要记住，当你在看元素周期表时，不要忘了镧系元素，有时候也会用到它们。

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