Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa July 1, 2017. (Photo by Rogan Ward/Reuters)

Festival goers having fun at the Balaton Sound music festival in Zamardi next to the Lake of Balaton, 110 km (68 miles) west of Budapest, July 8, 2017. (Photo by Sandor Csudai)

An Iraqi woman and foreigners use pair of compact discs as a filter to watch the partial solar eclipse in war-torn Baghdad, 29 March 2006. Without access to proper equipment to protect their eyes from the sun's rays, eclipse watchers in Iraq used makeshift filters. The moon blotted out the sun over northwest Africa early Wednesday, turning day into night in a total solar eclipse as it swept a shadowy path from the outer tip of Brazil to the steppes of Mongolia. (Photo by Hassan Ammar/AFP Photo)

Baker Magadma, a member of Palestinian sports group Bar Palestine, performs on the street in Gaza City, on June 3, 2016. Street workout, which is still new in Gaza, is a growing sport across the world with annual competitions and events. (Photo by Mohammed Abed/AFP Photo)

A soldier from the South Korean army special forces breaks stone plates with her head during a martial arts demonstration for Memorial Day at Korea War Memorial Museum in Seoul, South Korea, Monday, June 6, 2016.(Photo by Ahn Young-joon/AP Photo)

Aspiring models wait for their turn to be judged during auditions for the upcoming Lakme Fashion Week in Mumbai, India, June 30, 2016. (Photo by Shailesh Andrade/Reuters)

A woman greets a street artist at the San Fermin festival in Pamplona, northern Spain July 8, 2016. (Photo by Eloy Alonso/Reuters)