A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)

Vietnamese female commissioned officers of the signal force march during a parade marking their 70th National Day at Ba Dinh square in Hanoi, Vietnam September 2, 2015. (Photo by Reuters/Kham)

2016 Rio Olympics, Weightlifting, Final, Women's 63kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 9, 2016. Marina Rodriguez (CUB) of Cuba competes. (Photo by Stoyan Nenov/Reuters)

Netherland's Kitty van Male is hit in the face by Argentina's Agustina Habif during the women's quarterfinal field hockey game, August 15, 2016. (Photo by Carl de Souza/AFP Photo)

2016 Rio Olympics, Rhythmic Gymnastics, Final, Individual All-Around Final, Rotation 1, Rio Olympic Arena, Rio de Janeiro, Brazil on August 20, 2016. Melitina Staniouta (BLR) of Belarus competes using the hoop. (Photo by Ruben Sprich/Reuters)

Leidi, a member of the 51st Front of the Revolutionary Armed Forces of Colombia (FARC), poses for a picture at a camp in Cordillera Oriental, Colombia, August 16, 2016. A peace deal will end half a century of war and allow the rebels to reintegrate into Colombian society. (Photo by John Vizcaino/Reuters)

An Iraqi woman attends a festival commemorating the International Day of Peace in Baghdad, September 21, 2015. (Photo by Thaier al-Sudani/Reuters)

A woman pours alcohol from the bottle into her mouth at the Far Hills Race Day at Moorland Farms in Far Hills, New Jersey, October 17, 2015. Young locals in New Jersey catch up with friends from school and college days at the Far Hills Race Day, which started as a fox-hunting event in the early 1900s. Many racegoers first went to the Hunt, as it's known locally, as children, but nowadays it's an alcohol-fuelled party for them. Makeshift bars are set up in cars, with the horses' efforts on the turf sometimes a backdrop to the main event. (Photo by Stephanie Keith/Reuters)