“Slow”. A calm cow in the messy streets of Jodhpur. Photo location: India. (Photo and caption by Matthias Troeger/National Geographic Photo Contest)

Doris Pennman adjusts her umbrella as she walks along Mission Beach on January 8, 2005 in San Diego, Califonia. (Photo by Sandy Huffaker/Getty Images)

A Muslim Shi'ite boy carries a toy gun while standing next to a picture of Hezbollah leader Sayyed Hassan Nasrallah as he takes part in a march organised by Hezbollah during a re-enactment of the battle of Kerbala during a mourning process, ahead of the day of Ashura, in Saksakieh village, southern Lebanon, October 18, 2015. Ashoura, the most important day in the Shi'ite calendar, commemorates the death of Imam Hussein, grandson of the Prophet Mohammad, in the 7th century battle of Kerbala. (Photo by Ali Hashisho/Reuters)

Komodo Judo by Andrey Gudkov. Finalist, Amphibians & Reptiles. Two large male Komodo dragons hissing angrily at each other in Indonesia’s Komodo national park. Komodo dragons can grow up to 8ft. (Photo by Andrey Gudkov/Wildlife Photographer of the Year 2015)

A visitor holds an Israeli-made rifle during the 8th International Land and Naval Defense system exhibition, in New Delhi, India, on February 6, 2014. (Photo by Anindito Mukherjee/Reuters)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

A protester uses molotov cocktails against riot police during May Day protests on May 1, 2010 in Athens, Greece. (Photo by Milos Bicanski /Getty Images)