An Israeli soldier from the Nahal Infantry Brigade runs through smoke released from a smoke grenade during an urban warfare drill near an abandoned hotel in Arad, southern Israel February 8, 2017. (Photo by Amir Cohen/Reuters)

Russian soldiers dressed in Red Army World War II uniforms attend a rehearsal for the Nov. 7 parade in the Red Square with Spassky Tower in the background, in Moscow, Russia, Friday, November 6, 2015. The parade marks the 74th anniversary of a November 7 parade on Red Square when soldiers went directly to the front during World War II. For decades Nov. 7 was a holiday celebrating the 1917 Bolshevik Revolution. (Photo by Ivan Sekretarev/AP Photo)

Georgie Bain takes a selfie with her horse in “Best Friends” in Aberdeen, United Kingdom, Date Unknown. For the first time, the founders of the Comedy Wildlife Photography Awards have launched a photography award show giving proud pet owners a chance to show off their quirky pets. (Photo by Georgie Bain/Barcroft Images/Comedy Pet Photography Awards)

A Philippine boy collects used plastic bottles to be sold at a junk shop at Divisoria market in Manila on November 29, 2017. (Photo by Noel Celis/AFP Photo)

Dancers at the Windmill Theatre in London, England practice a routine wearing gas masks and hard-hats with their costumes, 1940. (Photo by Hulton Archive/Getty Images)

Director Taro Kambe directs as he watches acting with VR headset during a rehearsal for ROCKET's 3D virtual reality adult film at the company's studio in Tokyo, Japan, July 31, 2017. Japan is the world's second biggest virtual reality market after the United States and the adult entertainment industry and gaming sector are turning to VR as a new way to distribute content. (Photo by Kim Kyung-Hoon/Reuters)

In this January 29, 2017 photo, musicians perform for dancers on the shores of Lake Titicaca, as they practice before their presentation for the Virgin of Candelaria celebrations in Puno, Peru. Dancers in colorful masks and elaborate costume celebrate the Virgin of Candelaria, patron saint of communities along the shore of Lake Titicaca, in what's considered the largest Catholic festival in the Andes. (Photo by Rodrigo Abd/AP Photo)

A history enthusiast, dressed as a soldier, marches before the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna, Czech Republic December 3, 2016. (Photo by David W. Cerny/Reuters)