By Stephen Dowling/Images chosen by Javier Hirschfeld, 21st December 2021 As the world entered its second full year of the coronavirus pandemic, masks became a ubiquitous sight, from sports stadiums to the highest political offices.   (Image credit: Edgar Su/Reuters/Getty Images) Crowd of Tokyo train commuters in masks (Credit: Yasuyoshi Chiba/AFP/Getty Images) A world concealed December … Continue reading “2021: The year of the mask”, BBC Future