for mask wearing....from that report...
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COVID-19 incidence was 37% lower in schools that required teachers and staff members to use masks and 39% lower in schools that improved ventilation. Ventilation strategies associated with lower school incidence included dilution methods alone (35% lower incidence) or in combination with filtration methods (48% lower incidence).
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btw, since you rely on your own expert, Dr. Risch, go lightly on questioning the thousands of others who disagree with him., since the "preponderance of evidence" favors the vast majority...make logical sense to you?
Link: https://www.cdc.gov/mmwr/volumes/70/wr/mm7021e1.htm