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)

This picture taken on June 25, 2019 shows couples wait for their turn for their pre-wedding photo shoot at the Love Story in Rome Studio in Beijing. Increasingly elaborate pre-wedding photos are a booming industry in China, as young couples spend time and cash lining up glamorous photo shoots to display on their big day. (Photo by Fred Dufour/AFP Photo)

Pittsburgh police officers stand near a Port Authority bus that had fallen into a sinkhole along 10th Street and Penn Avenue in Pittsburgh on Monday, October 28, 2019. The bus and a car fell in the sinkhole shortly before 8 a.m. One person was taken to the hospital for a minor injury. (Photo by Kristina Serafini/Pittsburgh Tribune-Review via AP Photo)

The finishing touches are made to a new wax figure of Theresa May at Madame Tussauds in London, England on November 7, 2017. (Photo by Victoria Jones/PA Wire)

An army dog stands up as retiring soldiers salute their guard post before retirement in Suqian, Jiangsu province, China on November 29, 2017. (Photo by Reuters/China Stringer Network)

Indian young men wearing traditional folk dance “Bhangra” attire of Punjab, sit on see-saws and sip on soft drinks at a park before their performance during the Khalsa College International Folk Festival 2017 in Amritsar, India, 29 November 2017. The festival is aimed to promote cultural ties between India and participating countries. (Photo by Raminder Pal Singh/EPA/EFE)

A man who was set on fire by people accusing him of stealing during a rally against Venezuela's President Nicolas Maduro runs amidst opposition supporters in Caracas, Venezuela, May 20, 2017. (Photo by Marco Bello/Reuters)

An unidentified elderly woman, who was knocked over during the melee after a shot was fired in the direction of President Ford, is comforted by a passerby in San Francisco, September 23, 1975. (Photo by AP Photo)