Timeline for When was it first discovered that face masks protect against disease?
Current License: CC BY-SA 4.0
3 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 23, 2022 at 3:35 | history | edited | njuffa | CC BY-SA 4.0 |
Minor wordsmithing
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| Jul 22, 2022 at 22:24 | history | edited | njuffa | CC BY-SA 4.0 |
Minor word smithing
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| Jul 22, 2022 at 22:16 | history | answered | njuffa | CC BY-SA 4.0 |