For some of these diseases, we have powerful and safe medicines for use in mass prevention campaigns.
就上述疾病中的某些而言，我们已具备强效和安全的药物，可用于开展大规模预防运动。
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This very low base-rate means that any precursors of a quake would have to be incredibly reliable if decision-makers are to feel safe in using them to order mass evacuations.
For zero nukes would make no sense if this left the world safe for the sorts of mass conventional warfare that consumed the first half of the 20th century.