In collaboration with the Pennsylvania Department of Transportation, Allegheny College art students repurpose used street signs as art materials to create the PennDOT Road Sign Sculpture Garden in Meadville, Pennsylvania, USA on August 19, 2017. (Photo by Brian Cahn/ZUMA Wire/Rex Features/Shutterstock)

British Prime Minister Boris Johnson visits the Pavegen stand, a company that converts footsteps into energy, at the Innovation Zone during the UK-Africa Investment Summit in London, Britain on January 20, 2020. (Photo by Leon Neal/Pool via Reuters)

Homeless people receive free food offered by the Telangana state governement during a 21-day government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus in Hyderabad on March 26, 2020. (Photo by Noah Seelam/AFP Photo)

The workers dry the pipe papade made from seasoned and colored dough, during the containment imposed by the government as a preventive measure against COVID-19, in Agartala, the capital of the state of north-east India on May 5, 2020. (Photo by Abhisek Saha/Le Pictorium Agency via ZUMA Press/Rex Features/Shutterstock)

Iranian athlete Maryam Toosi practises on the rooftop of her apartment building following the closure of sports facilities as part of measures aimed at containing the COVID-19 coronavirus, in Iran's capital Tehran on May 19, 2020. The coronavirus pandemic has forced the world's athletes to keep fit in confinement. The novel coronavirus has claimed the lives of nearly 7,200 people in Iran, making it the deadliest outbreak in the Middle East. The government ordered the closure of sports facilities in mid-March as part of measures aimed at containing the virus. (Photo by Atta Kenare/AFP Photo)

In a photo taken on October 7, 2020 a woman holds two dogs as she waits for a train in Suncheon. (Photo by Ed Jones/AFP Photo)

Tigray refugees who fled the conflict in the Ethiopia's Tigray ride a bus going to the Village 8 temporary shelter, near the Sudan-Ethiopia border, in Hamdayet, eastern Sudan, Tuesday, December 1, 2020. (Photo by Nariman El-Mofty/AP Photo)

A staff member demonstrates how she puts on the helmet of a mock space suit at the C-Space Project Mars simulation base in the Gobi Desert outside Jinchang, Gansu Province, China, April 17, 2019. The facility – comprising several interconnected modules including a greenhouse and a mock decompression chamber – opened its doors to the public. (Photo by Thomas Peter/Reuters)