コロナ感染者急減「なぜ？」　進む接種・外出自粛・気候変化…

コロナ感染者急減「なぜ？」　進む接種・外出自粛・気候変化…
https://www.sankei.com/article/20211009-BE7A6P7XQFI3ZILOOEU3MHHJ2A/

last-modified: 2021-10-10 09:32:54