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)

The players of Denmark huddle prior to the FIFA Women's World Cup qualifier match between Denmark and Sweden at Viborg Stadion on September 4, 2018 in Viborg, Denmark. (Photo by Lars Ronbog/FrontZoneSport via Getty Images)

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)

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)

Dancer Beth Bracegirdle of the Balbir Singh Dance Company practises at the Billingham Forum pool in Billingham, UK on July 20, 2016, ahead of the 52nd Billingham international folklore festival of world dance in August. (Photo by Owen Humphreys/PA Wire)

Nuns from the United States dance as they wait for the Holy Mass with Pope Francis (not seen) at the Campus Misericordiae in Brzegi, Poland, 31 July 2016. Today Pope Francis will celebrate the holy mass ending the World Youth Day 2016 in Poland. (Photo by Marcin Obara/EPA)

Members of the Wasteland Warriors from the movie “MadMax” pose during the Wacken Open Air festival on August 4, 2016 in Wacken, Germany. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Alexander Koerner/Getty Images)