A military band playing during the Immortal Regiment march in Vladivostok, Russia on May 9, 2016. The celebrations marked the 71st anniversary of the defeat of Germany in WWII. (Photo by Yuri Smityuk/TASS/Getty Images)

These black-and-white photos are taken from the new book “Armoured Warfare in the First World War 1916 – 1918” by Anthony Tucker-Jones and published by Pen & Sword Military. Here: British troops hitch a ride on a Mark IV after the massed tank fleet spearheading attack at Cambrai on November 20, 1917. (Photo by Anthony Tucker-Jones/Mediadrumworld.com)

A People's Liberation Army (PLA) commando jumps through a fire hoop part of an exercise during an open day event at the Ngong Shuen Chau Barracks, the PLA navy base in the territory, in Hong Kong, China, 01 July 2015. Thousands of visitors attended the PLA open day yesterday and today to mark the 16th anniversary of the handover from British rule. (Photo by Jerome Favre/EPA)

Military helicopters fly in formation above a billboard with a picture of China's late Chairman Mao Zedong during a training session for the upcoming parade marking the 70th anniversary of the end of World War Two, on the outskirts of Beijing, July 2, 2015. Troops from Russia and Mongolia will march together with Chinese forces in a parade in Beijing in September to commemorate the end of World War Two, the government and state media said on Thursday, confirming the first two foreign participants. (Photo by Jason Lee/Reuters)

Kayaks, 7, poses for a picture holding toy gun in a camp where Christians displaced by Islamic State militants are living, in Irbil, Iraq, Friday, December 23, 2016. Iraq’s Christians are marking the holiday in his camp for displaced people with a sense of worry and despair, unable to return to their towns they were forced to flee two years ago by the Islamic State group’s onslaught. (Photo by Manu Brabo/AP Photo)

Hospitality staff members laugh as they stand on Tiananmen Square before the closing ceremony of China's 19th Party Congress at the Great Hall of the People in Beijing, Tuesday, October 24, 2017. The ruling Communist Party on Tuesday formally lifted Xi Jinping's status to China's most powerful ruler in decades, setting the stage for the authoritarian leader to tighten his grip over the country while pursuing an increasingly muscular foreign policy and military expansion. (Photo by Mark Schiefelbein/AP Photo)

A Police officer checks a man wearing a carnival costume in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. Police are also examining backpacks and bags and using metal-detecting wands before revelers are allowed into St. Mark's Square, the heart of the Venetian carnival. (Photo by Luigi Costantini/AP Photo)

A devotee with his body painted poses as he waits to perform during a ritual as part of the annual Shiva Gajan religious festival at Sona Palasi village, in West Bengal, India, April 11, 2016. Devotees offer sacrifices and perform acts of devotion during the festival in the hopes of winning the favour of Hindu god Shiva and ensuring the fulfillment of their wishes, and also to mark the end of the Bengali calendar year. (Photo by Rupak De Chowdhuri/Reuters)