据我所知，很难提炼或者制作纯的B2，B2要和其他混合才能保存，不知对不对。所以国内的B2不一定是纯粹的。

来源: qingxian 于 2024-05-31 13:10:20 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

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