Young Buddhist novice monks play at a Tibetan nomadic summer grazing area on July 24, 2015 on the Tibetan Plateau in Yushu County, Qinghai, China. Tibetan nomads face many challenges to their traditional way of life including political pressures, forced resettlement by China's government, climate change and rapid modernization. The Tibetan Plateau, often called “The Roof of the World”, is the world's highest and largest plateau. (Photo by Kevin Frayer/Getty Images)

Young couples compete in Rock' n'Roll & Co, an all- Russian acrobatic rock' n'roll competition in Kazan, Russia on November 4, 2017. Acrobatic rock’n’roll is a discipline for couples combining energetic dancing with acrobatic moves. (Photo by Yegor Aleyev/TASS via Getty Images)

A young woman holds her smartphone at Red Square with the Kremlin's Spasskaya Tower, right, and St. Basil Cathedral, center, in the background in Moscow, Russia, Monday, July 25, 2016. (Photo by Pavel Golovkin/AP Photo)

A young migrant cries as she waits to cross the Greek-Macedonian border, near the village of Idomeni, Greece March 3, 2016. Thousands of refugees and migrants wait on the border between Greece and Macedonia and about 30,000 refugees and other migrants are stranded in Greece, with 10,000 at the Idomeni border crossing to Macedonia. (Photo by Marko Djurica/Reuters)

A model has her hair done backstage before a fashion show by Greek designer Mary Katrantzou during the Mercedes-Benz China Fashion Week in Beijing, China, 27 March 2016. The fashion week runs until 31 March. (Photo by How Hwee Young/EPA)

Britain Soccer Football, West Ham United vs Manchester United, Barclays Premier League, Old Trafford on May 10, 2016. Police play football with a young West Ham fan before the match. (Photo by Eddie Keogh/Reuters/Livepic)

Kanphitcha Sungsuk, 21, (C), lines up with young men to speak to officers during an army draft held at a school in Klong Toey, the dockside slum area in Bangkok, Thailand, April 6, 2017. Thailand is widely seen as a paradise for gay and transgender people, but many complain of being treated as second-class citizens and the obligation to respond to the draft can be a nightmare when they turn 21. (Photo by Athit Perawongmetha/Reuters)

This photo taken on March 29, 2017 shows a young woman offering shots of liquer at a dance bar in Walking Street in Pattaya. Two hours east of Bangkok, Pattaya' s bawdy reputation hails from the Vietnam War era when US GIs partied in their downtime. (Photo by Roberto Schmidt/AFP Photo)