Aeroflot employees with a puppy at the canine service of Aeroflot at Sheremetyevo International Airport in Moscow Region, Russia on October 2, 2020, that has started to train service dogs to detect COVID-19 in people. (Photo by Vladimir Gerdo/TASS)

A couple walk in the Retiro park in Madrid on November 17, 2020 as a thick fog falls on the Spanish capital. (Photo by Gabriel Bouys/AFP Photo)

The Sun rises above the forest near Kiskorpad, Hungary, 02 January 2021. (Photo by Gyorgy Varga/EPA/EFE)

People ride a boat on the Tianquan Lake during a foggy day in Xuyi in China's eastern Jiangsu province on November 20, 2019. (Photo by AFP Photo/China Stringer Network)

Two animatronic velociraptors are on display during a technical rehearsal of “Walking with Dinosaurs The Live Experience” at the Indoor Stadium in Singapore, 29 August 2019. “Walking with Dinosaurs The Live Experience” is based on the BBC series of the same name and will run from 29 August to 08 September. (Photo by Wallace Woon/EPA/EFE/Rex Features/Shutterstock)

Andre Krumbiegel drives in a «SIL» pointed plough through the pink fog of a smoke body in Saxony, Germany on October 2, 2019. The occasion is the forthcoming Eastern Bloc meeting on 6 October in Großhartmannsdorf, to which motor vehicles and commercial vehicles from former socialist countries can be brought, exhibited and demonstrated. Photo by Sebastian Kahnert/dpa-Zentralbild/Keystone)

Members of a dance troupe participate in the Cabildo de Getsemani parade as part of the 208th Independence celebrations in Carta​gena, Colombia, 10 November 2019. (Photo by Ricardo Maldonado Rozo/EPA/EFE)

A person watches the sunrise from the Edge observation deck at Hudson Yards on the first day of spring on March 20, 2021 in New York City. (Photo by Noam Galai/Getty Images)