Herd immunity occurs when the majority of a population is immune to a disease or virus.
根据这个定义,美国没有达到对COVID-19的Herb immunity, 你说呢?
Herd immunity occurs when the majority of a population is immune to a disease or virus.
根据这个定义,美国没有达到对COVID-19的Herb immunity, 你说呢?
• 人是不是发烧,员工是不是病假,医院是不是挤和态度无关。20年就是一批批的感染 -遥遥- ♀ (45 bytes) () 12/24/2022 postreply 16:01:15