Ukrainian state emblem is seen on a gun's holster as soldiers guard naval base in the village of Novoozernoye, some 91 km west of Crimean capital Simferopol, Ukraine, on Monday, March 3, 2014. Ukraine says Russian forces controlling the strategic region of Crimea are demanding that the crew of two Ukrainian warships in Sevastopol's harbor must surrender. (Photo by Ivan Sekretarev/AP Photo)

An abandoned tank left by Boko Haram, February 20, 2016, seen on the road to Michika, Nigeria – a town formerly occupied by the insurgents. On April 14, 2014, 300 schoolgirls in the Chibok village in Nigeria were kidnapped by the terrorist group, Boko Haram. Two years later, the majority of these girls are still missing. According to the Global Terrorism Index Report 2015, Boko Haram, which operates mainly in Nigeria, has become the most deadly terrorist group in the world. (Photo by Danielle Villasana)

This July 2014 image provided by the Bureau of Land Management shows the interior of the Natural Trap Cave in north-central Wyoming. The cave holds the remains of tens of thousands of animals, including many now-extinct species, from the late Pleistocene period tens of thousands of years ago. Scientists have resumed digging for the first time in more than 30 years. (Photo by AP Photo/Bureau of Land Management)

A dog walks past a handmade replica of Lamborghini Diablo outside a garage rented by Wang Yu and Li Lintao on the outskirts of Beijing, August 21, 2014. Chinese race car enthusiasts Wang Yu and Li Lintao, both in their 30s, have finished designing and making two replicas of the Lamborghini Diablo, which can reach the top speed of 310km/h, and are currently working on a replica of the T-Rex motorcycle. They spent approximately 5 million yuan (around USD 811,899) to buy parts and hire workers, and about 6 years to assemble them with the knowledge they gained from studying mechanology for nearly a decade abroad. Wang and Li went popular after showing their first handmade replica of Lamborghini Diablo at the Beijing International Automobile Exhibition in 2012, and sold their second Lamborghini replica to Alibaba as a collection. (Photo by Petar Kujundzic/Reuters)

Fans of the East German Trabant car gather for their 7th annual get-together on August 23, 2014 in Zwickau, Germany. Hundreds of Trabant enthusiasts arrived to spend the weekend admiring each others cars, trading stories and enjoying activities. The Trabant, dinky and small by modern standards, was the iconic car produced in former communist East Germany and today has a strong cult following. (Photo by Matthias Rietschel/Getty Images)

In a photo taken on August 30, 2014 a man brushes his dog as he waits to take part in a competition at a dog show in Seoul. Some 2000 dogs took part in the three-day show organised by the Korea Kennel Federation which was celebrating its 58th anniversary. Dog ownership in South Korea is a growing industry widely reported to have passed 10 million in 2013, with private expenditure on pet supplies increasing some 14 percent per year since 2000, according to a report by the Nonghyup Economic Research Institute. (Photo by Ed Jones/AFP Photo)

South African maidens wrap themselves in blankets as they head to a ritual bath in a local river on September 5, 2014 at the eNyokeni Royal Palace in Nongoma in the KwaZulu-Natal region ahead of the 13th anniversary of the Reed Dance (uMkhosi woMhlanga) celebrated by the Zulu King Goodwill Zwelithin. As part of the ceremony, the young women dance bare-breasted for the king, each carrying a long reed, deposited later as they approach the King and is a cultural celebration that promotes respect for young women, and preserves the custom of keeping girls as virgins until marriage. (Photo by Marco Longari/AFP Photo)

This Monday, September 15, 2014 photo shows glazed bricks displayed at the Iraqi National Museum in Baghdad. The Islamic State militants seek to purge society of all influences that don't conform with their strict, puritanical version of Islam. That means destroying not only relics seen as pagan but also Muslim sites they see as contradicting their ideology, particularly Sunni Muslim shrines they see as idolatrous as well as mosques used by Shiites, a branch of Islam they consider heretical. (Photo by Hadi Mizban/AP Photo)