某些人的记忆还不如一条鱼，疫情还没到美国时华人大批大批寄口罩回大陆，到美国之后PPE严重短缺，回忆一下当时新闻？

US sent millions of face masks to china earlier this year, ignoring pandemic warning signs

https://www.washingtonpost.com/health/us-sent-millions-of-face-masks-to-china-early-this-year-ignoring-pandemic-warning-signs/2020/04/18/aaccf54a-7ff5-11ea-8013-1b6da0e4a2b7_story.html

The World Needs Masks. China Makes Them, but Has Been Hoarding Them.

https://www.nytimes.com/2020/03/13/business/masks-china-coronavirus.html