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来源: 于 2020-02-09 08:13:59 [旧帖] [给我悄悄话] 本文已被阅读：次

On 11 June 2009, the WHO declared an H1N1 pandemic, moving the alert level to phase 6, marking the first global pandemic since the 1968 Hong Kong flu.[28] On 25 October 2009, U.S. President Barack Obama officially declared H1N1 a national emergency[29]