5 feet distance > face mask. A mask is recommend in case you can't keep a safe distance, like in buildings, vehicles and in a crowd. Whenever possible keep a distance.
A single sneeze can travel up to 26 feet... the mask has the objective of not letting anything escape your mouth and nose, i get what they are doing and the teacher surely is special but it wouldn't kill them to use a mask... in fact it's better for them
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