An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

A dune buggy driver trains before competing in a sand dune drag racing event on January 8, 2016, as part of the Liwa 2016 Moreeb Dune Festival in the Liwa desert, some 250 kilometres southwest of Abu Dhabi. The festival, which attracts participants from around the Gulf region, includes a variety of races (cars, bikes, falcons, camels and horses) or other activities aimed at promoting the country's folklore. (Photo by Karim Sahib/AFP Photo)

Manuela (L) and Marta, members of the Revolutionary Armed Forces of Colombia (FARC), pose for a picture at a camp in the Colombian mountains on February 18, 2016. Many of these women are willing to be reunited with the children they gave birth and then left under protection of relatives or farmers, whenever the peace agreement will put an end to the country's internal conflict. (Photo by Luis Acosta/AFP Photo)

A man runs after he tried to put himself on fire during a protest at a makeshift camp at the Greek-Macedonian border near the village of Idomeni on March 22, 2016. Greece will not be able to start sending refugees back to Turkey from March 20, 2016, the government said, as the country struggles to implement a key deal aimed at easing Europe's migrant crisis. The numbers are daunting: officials said as of Saturday there were 47,500 migrants in Greece, including 8,200 on the islands and 10,500 massed at the Idomeni camp on the Macedonian border. (Photo by Andrej Isakovic/AFP Photo)

A hot air balloon in the likeness of Yoda from Star Wars prepares for liftoff at the 21st Philippine International Hot Air Balloon Festival at the former Clark US Air Force base in Pampanga Province, Philippines on February 9, 2017. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Muslim children play sack race during Eid-al-Fitr celebration in Taguig city, south of Manila July 18, 2015. (Photo by Romeo Ranoco/Reuters)

A woman sits as she gets a tattoo on her leg during the annual Panama City Ink Fest in Panama City August 16, 2015. (Photo by Carlos Jasso/Reuters)

Sheriffs' deputies look at wreckage from the crash of Virgin Galactic's SpaceShipTwo near Cantil, California November 2, 2014. A suborbital passenger spaceship being developed by Richard Branson's Virgin Galactic company crashed during a test flight on Friday at the Mojave Air and Space Port in California, killing one crew member and seriously injuring the other, officials said. (Photo by David McNew/Reuters)