An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

A student from the General Yermolov Cadet School takes part in weapons training during a two-day field exercise near the village of Sengileyevskoye, just outside the south Russian city of Stavropol April 13, 2014. The General Yermolov Cadet School in the southern Russian city of Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

The Anthem Veterans Memorial was created in Anthem, Arizona, in order to commemorate the service and sacrifice of the US soldiers that have lost their lives in order to bring peace and democracy to many nations throughout the world. Without these brave souls so many countries around the world would not be able to enjoy the fruits of Western Democracy. These pillars serve as a place of honor for military veterans, their friends and family, and to those people who want to pay their respect to the courageous men and women who continue to serve the United States. (Photo by Anthem Community Council)

Firefighters pull a pig as they try to rescue it from a well at a pig farm in Huanghua township of Leqing, Zhejiang province, April 25, 2014. Seven local firefighters successfully rescued a 300 kg (661 lbs) pig which fell down a well on Friday morning, local media reported. (Photo by Reuters/China Daily)

Players battle for the ball during their match at the swamp soccer China tournament in Beijing, June 26, 2014. The 32 teams from across the country participated in the soccer event to celebrate the 2014 World Cup in Brazil. (Photo by Kim Kyung-Hoon/Reuters)

Buses are stranded in a flooded street in Fuzhou, Fujian province, July 24, 2014. Typhoon Matmo hit Taiwan on Wednesday, bringing heavy rain and strong winds, shutting financial markets and schools. It passed the island and headed into China, downgraded from typhoon to tropical storm. (Photo by Reuters/Stringer)

A hairdressing mannequin is seen outside a hair salon amid as Typhoon Matmo hits Nantong, Jiangsu province July 25, 2014. Matmo, which made landfall in Fujian Province on Wednesday, has brought strong winds and heavy downpours to more areas in China after it moved northward on Thursday, Xinhua News Agency reported. (Photo by Reuters/Stringer)

American free climber Dean Potter walks on a 41-meter-long and two-centimeter-wide slackline over Enshi Grand Canyon at an altitude of 1,800m on April 22, 2012 in Enshi, Hubei Province of China. Potter successfully finished the lone slackline walk in about three minutes without taking any protective measures. (Photo by ChinaFotoPress/ChinaFotoPress)