尸检分析显示出存在一种未知的病毒，以及一种已知的有毒细菌的证据。
Postmortem analysis showed the presence of an as yet unidentified virus, as well as evidence of a know bacterial toxin.
有一小部分重要而快速的改变是难以预料到的 -- 已知的未知数。
There is a small set of fast moving important change that is hard to predict -- the known unknowns.
客观的不确定性关乎唐纳德·拉姆斯菲尔德(在另一种语境中)提及的“已知的未知方面”。
Objective uncertainty is about what Donald Rumsfeld (in a different context) referred to as the "known unknowns".
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