Syrian refugee and Olympic swimmer Yusra Mardini is pictured during a training session in a pool at the Olympic park in Berlin, Germany on April 26, 2018. (Photo by Fabrizio Bensch/Reuters)

Two female soldiers have their picture taken by an army colleague at Mangyongdae. (Photo by Gavin John/Mediadrumworld.com)

A model waits to present a creation by Chinese designer Hu Sheguang for his collection show during China Fashion Week S/S 2016 in Beijing October 26, 2015. (Photo by Jason Lee/Reuters)

North Korea's Samjiyon Orchestra performs at Pyongyang Grand Theatre in Pyongyang, North Korea, September 18, 2018. (Photo by Pyeongyang Press Corps/Pool via Reuters)

North Koreans who signed up to join the army train in the midst of political tension with South Korea, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang August 23, 2015. Top aides to the leaders of North and South Korea resumed talks on Sunday after negotiating through the night in a bid to ease tensions involving an exchange of artillery fire that brought the peninsula to the brink of armed conflict. (Photo by Reuters/KCNA)

People wear clothing to protect them from the heat while riding along a street in Hanoi, Vietnam, 24 April 2019. North and central Vietnam was recently affected by extreme hot weather, with the highest temperatures reaching over 40 degrees Celcius, according to the National Centre for Hydro-meteorological Forecasting. (Photo by Luong Thai Linh/EPA/EFE)

Celebrities attend The National Reality TV Awards 2016 at the Porchester Hall in London, United Kingdom on September 29, 2016. (Photo by FameFlynet UK)

Technicians check a CRH high-speed train at Shanghai Hongqiao High-speed train base on December 28, 2011 in Shanghai, China. China's railway stations have started today to sell tickets for the 2012 Spring Festival travel season scheduled to run between January 8th and February 16th, centred around the Chinese New Year which this year falls on January 23rd. (Photo by ChinaFotoPress/Getty Images)