Puerto Rico's Grace Claxton warms up before competing in the Women's 400m Hurdles Round 1 during the athletics event at the Rio 2016 Olympic Games at the Olympic Stadium in Rio de Janeiro on August 15, 2016. (Photo by Jewel Samad/AFP Photo)

Brazil's Victoria Chamorro failed to stop the ball during their women's classification 7th-8th place water polo match against China at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Friday, August 19, 2016. (Photo by Sergei Grits/AP Photo)

Bronze medalist Carlos Coloma Nicolas of Spain celebrates after finishing third in the cross-country cycling mountain bike race at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Saturday, August 20, 2016. (Photo by Patrick Semansky/AP Photo)

Baby giraffe of Niger (Giraffa Camelopardalis) “Kenai” (R), born on August 25, 2016, kisses his mother “Dioni” on August 31, 2016 at the zoo of La Fleche, northwestern France. (Photo by Jean-Francois Monier/AFP Photo)

Fifth-grade students of the General Yermolov Cadet School get prepared before their first military tactical exercise on the ground, which includes radiation resistance classes, forest survival studies and other activities, in Stavropol, Russia, September 10, 2016. Picture taken September 10, 2016. (Photo by Eduard Korniyenko/Reuters)

Models walk down the runway during the Addition Elle/Ashley Graham Lingerie Collection fashion show during the Spring 2016 Style 360 on September 15, 2016 in New York City. (Photo by Fernando Leon/Getty Images)

Convention goers dressed as bright colored Wookiees, a fictional species from the US epic space opera franchise Star Wars, prepare for a group photo outside the Comic Con 2016 in San Diego, California, USA, 22 July 2016. The San Diego Comic Con 2016 runs from 21 until 24 July. (Photo by David Maung/EPA)

An undated handout image provided by UNICEF Germany on 20 December 2016 shows the “UNICEF Photo of the Year 2016” by Iranian freelance photographer Arez Ghaderi. Ghaderi won the first prize for his picture of a girl in a makeshift tent city in the Razavi Khorasan province, Iran, it was announced at a ceremony in Berlin, Germany on 20 December 2016. (Photo by Ariz Ghaderi/EPA/UNICEF Deutschland)