那三年死亡率明顯高於其他年份，尤其是60年，死亡率是其他年份的2倍多，如何解釋？

來源: 91468 於 2021-12-08 17:14:56 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.