必须把资料保存起来，这样才不至于无意中删除。
Information must be stored so that it is secure from accidental deletion.
这些资料保存了不同的传统关于瘟疫的数量和性质，以及戏剧中的主要角色：上帝，摩西，亚伦。
These sources preserve different traditions on the number and the nature of the plagues, as well as the principal actors in the drama: God, Moses, Aaron.
备份资料保存多久？
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