A teenage girl from the Santa Marta favela slum puts on a pair of high heels for a group debutante ball organized by the Pacifying Police Unit from her neighborhood in Rio de Janeiro, Brazil, Friday, August 29, 2014. The ball, which relied on volunteers who coiffed and made up the girls and a formal wear shop that loaned the dresses, helped build goodwill between pacified favelas' residents and the officers who patrol them. (Photo by Silvia Izquierdo/AP Photo via The Palm Beach Post)

Apple CEO Tim Cook discusses the new iPhone 6 and iPhone 6 plus on Tuesday, September 9, 2014, in Cupertino, Calif. The iPhone 6 will have a screen measuring 4.7 inches, while the iPhone 6 Plus will be 5.5 inches. (Photo by Marcio Jose Sanchez/AP Photo)

“APOPO’s Training Center, situated on Sokoine Univeristy of Agriculture (SUA) in Tanzania, was established in 2000 to accommodate training and testing of mine detection rats in near-to-real conditions”. – APOPO

Photo: MDR (Mine Detection Rat) learn to look for mines. (Photo by APOPO's HeroRATs)

Taronga Zoo's elephant baby, as yet unnamed, is seen at Taronga Zoo on March 12, 2010 in Sydney, Australia. The Asian Elephant calf has continued to make progress following a protracted labour that spanned six days. The calf was originally believed to have died in the womb during labour but surprised veterinarians and zoo staff with an unexpected delivery early Wednesday morning. (Photo by Bobby-Jo Vial/Taronga Zoo via Getty Images)

A beachgoer walks past a buoy that washed ashore after Hurricane Isabel made landfall September 19, 2003 in Virginia Beach, Virginia. (Photo by Joe Raedle/Getty Images)

A giant sinkhole in Guatemala City, on May 31, 2010. More than 94,000 were evacuated as the storm buried homes under mud, swept away a highway bridge near Guatemala City and opened up several sinkholes in the capital. (Photo by Casa Presidencial/Reuters via The Atlantic)

Mikhail Kalashnikov, the father of the world's most popular assault rifle, is handed an AK-74 November 23, 2002 in Izhevsk,1000 East km. from Moscow. November 23 marked the 55th anniversary of the release of the first Kalashnikov gun. According to the Moscow-based Center for Analysis of Strategic and Technologies some 70 million to 100 million Kalashnikovs have been built worldwide since 1947, compared about 7 million to Kalashnikov's Western rival the M-16 assault rifles. (Photo by Oleg Nikishin/Getty Images)

Engine driver Josef Kowatsch (top L) steers a train through the NEAT Gotthard Base Tunnel during a media visit near the town of Erstfeld August 24, 2015. Crossing the Alps, the world's longest train tunnel should become operational at the end of 2016, consisting of two parallel single track tunnels, each of a length of 57 km (35 miles). (Photo by Arnd Wiegmann/Reuters)