A girl carries a rifle as she attends a rally by followers of the Shi'ite Houthi movement commemorating the death of Imam Zaid bin Ali in Sanaa, Yemen October 26, 2016. (Photo by Khaled Abdullah/Reuters)

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

“Show Time”. It's a normal behavior of mantis. They're doing defence. When they're afraid of; raising their arms and spreading their wings. They looks like smiling dancer. Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)

A man takes a photo of a radio antenna that's part of the Atacama Large Milimeter Array Observatory on March 12, 2013 at Llano de Chajnantor, about 43 miles (70 kilometers) from San Pedro de Atacama, Chile. The $1.5 billion ALMA facility, which had its official inauguration on March 13, is considered the world's most expensive ground-based observatory. (Photo by Felipe Trueba/EPA)

A partial Solar eclipse is seen just after sunrise over the Queens borough of New York across the East River on November 3, 2013 in New York. (Photo by Stan Honda/AFP Photo)

A woman covers her face as men throw colored powder at her during “Lathmar Holi” at the village of Barsana in the northern Indian state of Uttar Pradesh March 9, 2014. (Photo by Anindito Mukherjee/Reuters)

Revellers chat on Havana's Malecon seafront before performing at a carnival parade, Cuba, August 12, 2016. (Photo by Alexandre Meneghini/Reuters)

American soldiers with the 173rd Airborne Brigade Battle Company, on a battalion-wide mission in the Korengal Valley, looking for caves, weapons caches and known Taliban leaders, 2007. Tanner Stichter tends to Spc. Carl Vandeberge in the bushes moments after Vandeberge was shot in the stomach during a Taliban ambush, which killed one soldier and wounded two others. (Photo by Lynsey Addario)