People in Kathmandu joke that the face mask has now become part of the national dress – an indispensable accessory in an effort to protect themselves from the dust. Nepal has the worst air quality in the world, according to the Environmental Performance Index. (Photo by Pete Pattisson/The Guardian)

An eight-year-old St Bernard with the longest canine tongue in the world, measuring 18.58cm (7.31in) in length, as recorded by the Guinness World Records: Amazing Animals, in South Dakota, USA. (Photo by Kevin Scott Ramos/GWR/PA Wire)

People hold umbrellas as they walk past a flooded street in Taiyuan, Shanxi Province, China, July 19, 2016. (Photo by Reuters/China Daily)

A CRH train is seen passing through Nanjing South Railway Station, which is part of the Beijing-Shanghai High-Speed Railway Line, on March 27, 2011 in Nanjing, Jiangsu Province of China. The High-Speed railway line is 1,318 kilometres long, running between Beijing and Shanghai. The line will open on June 10, 2011. (Photo by ChinaFotoPress/Getty Images)

People are seen at Avalon Beach on December 18, 2020 in Sydney, Australia. A cluster of Covid-19 cases on the northern beaches of Sydney has grown to 28, prompting NSW health officials to urge residents of affected suburbs to stay home. Traffic at Sydney Airport has increased as people rush to leave the city with several states imposing quarantine restrictions for New South Wales residents. (Photo by Jenny Evans/Getty Images)

A man reacts over dead bodies prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (Photo by Bassam Khabieh/Reuters)

In this September 27, 2017 file photo, girls walk past a wall riddled with bullet holes from shootings between rival drug traffickers, at the Rocinha slum, in Rio de Janeiro, Brazil. Violence is on the rise in Rio's slums after several years of decline, and the killings of kids have shocked even residents long inured to deaths from gangs and police. (Photo by Silvia Izquierdo/AP Photo)

A Sadhu or a Hindu holy man performs to receive money from pilgrims at a makeshift shelter, before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India, January 10, 2018. (Photo by Rupak De Chowdhuri/Reuters)