Some copies of the Septuagint contain some books not included in the Hebrew canon but accepted in the early Christian canon.

有些希腊译本中的经卷不被收录在,希伯来文圣典中却有被早期基督教正经收录。

耶鲁公开课 - 旧约导论课程节选

So maybe they were just shoved there by people fleeing the Roman conquest in 70 .So that's up for grabs.

不过或许这些经卷是在公元70年罗马征战期间,人们在逃亡途中摆在那卖的。

耶鲁公开课 - 旧约导论课程节选