In this Saturday, April 13, 2019, file photo, Mariah Bell, center, of the U.S. reacts to her score with her teammates after performing her women's free program routine during the ISU World Team Trophy Figure Skating competition in Fukuoka, southwestern Japan. (Photo by Toru Hanai/AP Photo)

Children wearing military uniform take part in a parade, held by Russian servicemen, pupils of infant and primary schools, which is a public event to honour World War Two veterans and to mark the upcoming Victory Day, in Rostov-on-Don, Russia on April 25, 2019. (Photo by Sergey Pivovarov/Reuters)

Sloth “Paula” hangs from a branch in her enclosure at the zoo in Halle an der Saale, eastern Germany, on June 14, 2019. The two-toed sloth celebrated her 50th birthday and is, according to the zoo, the oldest sloth of the world. (Photo by Hendrik Schmidt/dpa/AFP Photo)

People spend the summer at Qingdao seaside in Shandong, China on July 3, 2019. The maximum temperature of Qingdao beach was 26 degrees Celsius on that day, and all the 9 sea bathing places were open, attracting a large number of visitors to the seaside to enjoy the cool world. (Photo by Huang Jiexian/ZUMA Press)

Mae Zelinsky, left, and Betty O'Beda test ammunition on a .30 caliber rifle at a Remington Arms plant on April 30, 1943. Many women took over jobs that were left vacant when men went overseas to fight in World War II. (Photo by AP Photo)

Vehicles pass through the heavy fog and air pollution that cover Skopje valley in the early morning, in Skopje, The Former Yugoslav Republic of Macedonia, 14 December 2017. According to media reports, Skopje is considered one of the most polluted cities in the world. (Photo by Georgi Licovski/EPA/EFE)

An employee operates a machine while attaching a lock to a silver chain at the jewelry department of the Krastsvetmet non-ferrous metals plant, one of the world's largest producers in the precious metals industry, in the Siberian city of Krasnoyarsk, Russia, December 14, 2016. (Photo by Ilya Naymushin/Reuters)

A skydiver dressed as Santa Claus prepares to leap out of a plane as 155 tandem skydivers set a new Guinness World Record over eight hours, over the Australian city of Wollongong, December 17, 2016. (Photo by Jason Reed/Reuters)