in Qayyarah, about 31 miles (50 km) south of Mosul, Iraq, Sunday, October 23, 2016.in Qayyarah, some 50 kilometers south of Mosul, Iraq, Sunday, Oct. 23, 2016. Islamic State fighters torched a sulfur plant south of Mosul, sending a cloud of toxic fumes into the air that mingled with oil wells the militants had lit on fire to create a smoke screen. (Photo by Marko Drobnjakovic/AP Photo)

A Black Pete interacts with children during the arrival of Sinterklaas, or Saint Nicholas, in Maassluis, Netherlands, Saturday, November 12, 2016. Sinterklaas and his helper Black Pete are at the center of a long-time controversy because Pete is often played by white people in blackface makeup. (Photo by Peter Dejong/AP Photo)

The Sugar Plum Fairy, Katherine Free, left, dances with the dog, Pig, during the Birmingham's Ballet “Mutt-cracker”, a rendition of the famous ballet “The Nutcracker”, in Birmingham, Alabama, December 8, 2016. (Photo by Brynn Anderson/AP Photo)

A horse- drawn carriage rides along the race course through the Thuringian Forest in Oberhof, Germany, 05 January 2017. Winter found its way to Saxony, Saxony- Anhalt, and Thuringia. In some regions it can get as low as negative 20 degrees overnight. (Photo by Martin Schutt/Zentralbild/DPA)

Rapper Pitbull performs onstage during Nickelodeon's celebration of the new Burbank facility on January 11, 2017 in Los Angeles, California. (Photo by Charley Gallay/Getty Images for Nickelodeon)

Inflatable dolls in the shape of ducks are seen in front of the National Congress during a protest against tax increases in Brasilia, Brazil, March 29, 2016. The campaign “I will not pay the Duck” is organized by the Federation of Industries of Sao Paulo (FIESP) and uses the duck symbol in reference to industries that pay high taxes. (Photo by Gregg Newton/Reuters)

French firemen wearing chemical protective suits take part in a mock chemical attack exercise at the Geoffroy Guichard stadium in Saint-Etienne, France, April 4, 2016 in preparation of security measures for the UEFA 2016 European Championship. (Photo by Robert Pratta/Reuters)

Supporters of former Democratic presidential candidate Bernie Sanders hold up posters at a “Black Men For Bernie” rally to gain support for third party candidates and protest the DNC during the 2016 Democratic National Convention on July 27, 2016 in Philadelphia, Pennsylvania. (Photo by Patrick T. Fallon/AFP Photo)