Children play on an abandoned car near a protest, which is against the dissolution of Yemen's parliament and the Shi'ite Muslim Houthi militia's tightening grip on power, in the southwestern city of Taiz, February 13, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

A woman takes cover as shots are fired by police officers as they face off with stone-throwing protesters, during an anti-government demonstration in Bujumbura, Burundi, 20 May 2015. Police officers fired shots and teargas canisters in running battles with protesters who demonstrated against Burundi's President Pierre Nkurunziza's bid for a third term. Presidential spokesman man said on 20 May that the country will postpone its parliamentary and local council elections, previously scheduled for 26 May, to 05 June 2015. According to the United Nations' refugee agency, more than 105,000 Burndians have fled the country to seek refuge in neighbouring countries such as Rwanda, DR Congo, and Tanzania. (Photo by Dai Kurokawa/EPA)

Visitors photograph an animatronic Tyrannosaurus Rex at the National Museum of Scotland, July 29, 2011. (Photo by David Moir/Reuters)

Miss California Crystal Lee performs during the Miss America 2014 pageant, Sunday, September 15, 2013, in Atlantic City, N.J. (Photo by Mel Evans/AP Photo)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

Children react as a carnivorous theropod known as the Australovenator dinosaur walks through crowds along the Southbank, in London, Monday, February 18, 2013. The dinosaur is one of many that can be visited at the Erth's Dinosaur Petting Zoo, visiting from Australia, the creatures can be touched and fed at the Southbank Centre. (Photo by Kirsty Wigglesworth/AP Photo)

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)