Senegalese wrestlers cover themselves in sand as they prepare to start their training program in Petit Mbao on March 29, 2021. As Covid-19 restrictions have been lifted, wrestlers now start prepare themselves for the start of wrestling tournaments. Senegalese wrestling, which has its roots in the ceremonies celebrating the end of harvests in Serer and Diola ethnic groups and remains surrounded by a thick cloud of mystical practice, is still extremely popular in this West African country. (Photo by John Wessels/AFP Photo)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)

An Indian toddler plays amid marigold flowers at a wasted flowers dumping site, besides a flower market in Mumbai, India, 28 September 2016. Marigold flowers are used in many religious ceremonies in the temples in India. Strung together they make colourful garlands and are used as an offering in temples and to decorate them. (Photo by Divyakant Solanki/EPA)

A woman rides a mini bicycle through crowds of Santa costumes in a park during the annual SantaCon on December 10, 2016 in London, England. The event sees hundreds of people walking the streets of London and drinking alcohol in Father Christmas and other festive costumes. (Photo by PA Wire)

Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

Michal Navratil of the Czech Republic performs after the men's 27 meter high dive final at the Swimming World Championships in Kazan, Russia, Wednesday, August 5, 2015. (Photo by Denis Tyrin/AP Photo)

A group of 1000 customers receive a facial massage at a sports centre in Jinan, Shandong province, China, May 4, 2015. A group of 1000 women were given a 30 minutes facial beauty treatment together on Monday that achieved a Guinness record for the largest group of people having beauty treatment in the same location, according to local media. (Photo by Reuters/Stringer)