Masks did slow down the spread of COVID:
https colon SLASH SLASH www DOT ncbi DOT nlm DOT nih DOT gov SLASH pmc SLASH articles SLASH PMC10022328 SLASH
April 12, 2017
September 04, 2017
November 03, 2017
November 24, 2017
Masks did slow down the spread of COVID:
https colon SLASH SLASH www DOT ncbi DOT nlm DOT nih DOT gov SLASH pmc SLASH articles SLASH PMC10022328 SLASH