The Eiffel Tower is illuminated during the traditional Bastille Day fireworks display in Paris, July 14, 2013. (Photo by Fred Dufour/AFP Photo)

Alphajet aircraft draw a heart-shaped message in the sky during the 2010 presentation show of the French aerobatics team Patrouille de France, over the French city of Salon-de-Provence. (Photo by Gerard Julien/AFP Photo)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

A Leyland lorry during the railway strike, “we supply both milk and baby” is chalked on the bonnet. (Photo by A. R. Coster/Topical Press Agency/Getty Images). 3rd October 1919

Horsemen take part in the Durbar festival parade in Zaria, Nigeria September 14, 2016. It is celebrated at the culmination of Muslim festivals Eid al-Fitr and Eid al-Adha. It begins with prayers, followed by a parade of the Emir and his entourage on horses, accompanied by music players, and ending at the Emir's palace. (Photo by Afolabi Sotunde/Reuters)

A Palestinian youth demonstrates his parkour skills on a street in Gaza City, January 15, 2016. (Photo by Suhaib Salem/Reuters)

The Blue Man Group performs on stage during a media preview ahead of their show in Singapore on March 31, 2016. Blue Man Group was started by three friends in New York in 1991 as a way to celebrate the human spirit through music, science, art and theater. (Photo by Roslan Rahman/AFP Photo)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)