Boys play basketball in the facilities of Belarus' Republican Clinic of Speleotherapy within a salt mine, as part of their treatment, near the town of Soligorsk, south of Minsk, February 19, 2015. According to the state clinic, more than 7,000 children and adults seek medical treatment for respiratory illness each year in the subsurface chambers of its facilities, located 420 metres underground between layers of potassium and stone salts in an operational salt mine. (Photo by Vasily Fedosenko/Reuters)

Kaylee Cantler, 15, of Waynesboro, Pa., applies blush during a natural makeup exercise at a modeling camp at the Courtyard Marriott Hotel in McLean, Va., on Monday, August 17th, 2015. (Photo by Brittany Greeson/The Washington Post)

The six-months-old female koala cub holds on to the back of zoo keeper Lena at the zoo in Duisburg, Germany, 23 October 2015. The yet unnamed baby weighs 580 grams. (Photo by Roland Weihrauch/EPA)

Young Turkana tribeswomen sing in a village near Baragoy, Kenya August 6, 2017. Kenyans are due to go to the polls on Aug. 8. to vote in presidential elections after a tightly-fought race between President Uhuru Kenyatta and main opposition leader Raila Odinga. (Photo by Goran Tomasevic/Reuters)

A boy covers his head with fallen leaves as he enjoys a stroll with his family in a park in downtown Frankfurt, Germany, November 6, 2016. (Photo by Kai Pfaffenbach/Reuters)

Chieftain Japarupi Waiapi shows a roasted monkey -part of Waiapi's diet, also based in Manioc and fruits- at the reserve in Amapa state in Brazil on October 13, 2017. When Waiapis walks into the Amazon forest surrounding their village, they do not see trees, but a kind of shopping mall providing medicine, food, shelter, tools and weapons all under the eye of multiple spirits. (Photo by Apu Gomes/AFP Photo)

In this picture taken on December 13, 2017, a woman commutes on a street on a cold day in Baoding. As temperatures dipped below freezing in a northern Chinese village, a group of parka-clad women tried to stay warm as they played mahjong around a small gas stove in a grocery store. (Photo by Fred Dufour/AFP Photo)

A close up of a caracal lynx's face looking into a camera on January 2014 in Western Cape, South Africa. (Photo by Dale Morris/Barcroft Media)