A P-51 Mustang named “Charlotte's Chariot” from the Southern Heritage Air Foundation flies past a cloud of smoke and fire from a nearby battle reenactment during the Wings Over Houston Airshow in Houston, on Saturday, November 1, 2014. Battle reenactments are part of the yearly show held at Ellington Airport. (Photo by Kar Hlava/AP Photo/Bay Area Citizen)

Men stroll past roadside vendors as a painted truck makes its way through the busy street in Kabul, Afghanistan, November, 1961. (Photo by Henry S. Bradsher/AP Photo via The Atlantic)

A large balloon of a face of “ojisan”, a middle aged man, floats in the sky above the grounds of Nishiki elementary school in Utsunomiya in Tochigi prefecture, 100km north of Tokyo on December 21, 2014. Members of art group “Me”, meaning “eye” in Japanese and the Utsunomiya Museum of Art launched an art installation “The Day an Ojisan's Face Floated in the Sky”, a 15-meter by 10-meter face balloon of the depicted man, who was auditioned in the city, looking down on his home town from the sky. (Photo by Yoshikazu Tsuno/AFP Photo)

Participants hang from ropes as they learn how to use safety gears at an experience centre for construction safety training in Beijing, September 5, 2014. The centre which opened in June 2014 was established to educate workers about construction safety. According to the centre, about 1,000 construction workers undergo 3-hour classes which comprises of 33 modules every month. (Photo by Kim Kyung-Hoon/Reuters)

Women play soccer as the Tungurahua volcano spews a column of ash during an eruption in Huambalo, Ecuador, Saturday, March 5, 2016. Tungurahua is 16,480 feet (5,023 meters) high and has been active since 1999. (Photo by Dolores Ochoa/AP Photo)

A roadside ice-cream vendor waits for customers at a market in New Delhi, India, April 7, 2016. The Indian economy is characterized by the existence of a vast majority of informal or unorganized labor employment. (Photo by Altaf Qadri/AP Photo)

A competitor wearing a kilt and standing on a barrel throws a bowling ball between her legs during the “Brigaball” contest at the annual Bundanoon Highland Gathering, showcasing traditional Scottish events, held in the town of Bundanoon, located southwest of Sydney, April 9, 2016. (Photo by David Gray/Reuters)

Performers are reflected in a displayed vehicle before going onto the stage during the Auto China 2016 auto show in Beijing, China, April 29, 2016. (Photo by Damir Sagolj/Reuters)