“The Challenge!” Young boy relishes in a game of tug of war before school. Photo location: Lake Titicaca, Peru. (Photo and caption by Paul Heyman/National Geographic Photo Contest)

Large trumpet vines spread across electrical lines next to a highway in Kinston, N.C., on June 23, 2014. (Photo by Janet S. Carter/Kinston Free Press via AP Photo)

Members of the Iraqi Army fire towards Islamic State militant positions at the south of Mosul, Iraq December 10, 2016. (Photo by Alaa Al-Marjani/Reuters)

Women pose for a picture at the entrance of the Carlton Hotel, in the government controlled area of Aleppo, Syria December 17, 2016. (Photo by Omar Sanadiki/Reuters)

A child coughs as migrants and refugees run away after Macedonian police fired tear gas at hundreds of Iraqi and Syrian migrants who tried to break through the Greek border fence in Idomeni, on February 29, 2016. Greek police said more than 6,000 people were massed at the border, in a buildup triggered by Austria and Balkan states capping the numbers of migrants entering their territory. (Photo by Louisa Gouliamaki/AFP Photo)

School children dressed in traditional attire eat breakfast before participating in a Republic day parade in Bangalore, India, Thursday, January 26, 2017. (Photo by Aijaz Rahi/AP Photo)

Military items for women are seen in a store in Erbil, Iraq January 24, 2017. (Photo by Marius Bosch/Reuters)