[S]cientists have learned a lot about airborne respiratory fluids and, in particular, what might make someone a superspreader, or superemitter. Certain attributes, such as the shape of one’s body, and certain behaviours, such as loud talking or breathing fast, appear to have a major role in spreading the disease..

TfW has staff enforcing mask protocols at all the busy stations and most travellers oblige, albeit some with ill grace.

He's a person with whom I work. (defining)

—Do you think I'm stupid? —Hey, your words, not mine.