A general view shows smoke and volcanic ashes billowing from volcano Cotopaxi in Pedregal, Ecuador, late 07 October 2015. (Photo by Jose Jacome/EPA)

Students of the General Yermolov Cadet School wait to board an airplane for a parachute jump at an airdrome in the village of Novomaryevskaya outside the southern city of Stavropol, Russia, May 13, 2016. (Photo by Eduard Korniyenko/Reuters)

General Atmosphere at 2014 New York Comic Con – Day 3 at Jacob Javitz Center on October 11, 2014 in New York City. (Photo by Laura Cavanaugh/Getty Images)

Two Inuit children at Point Barrow, Alaska, holding the tusks of a large walrus, probably killed for food, circa 1930. (Photo by General Photographic Agency/Getty Images)

Pope Francis attends a circus performance during his weekly general audience at Paul VI hall on December 22, 2016 at the Vatican. (Photo by Alberto Pizzoli/AFP Photo)

General view of the entrance to the Swarowski Crystal World museum on its reopening day following renovation, in the western Austrian village of Wattens April 30, 2015. (Photo by Dominic Ebenbichler/Reuters)

General view of a herbal store in Cairo, Egypt January 10, 2017. In an economic crisis that has led to a shortage of medicines, Egyptians are skipping trips to drug stores and instead turning to herbal remedies to treat every-day illnesses. (Photo by Mohamed Abd El Ghany/Reuters)

A decorated human skull or “natitas”, sits on a blanket inside the Cementerio General chapel, during the Natitas Festival celebrations, in La Paz, Bolivia, Tuesday, November 8, 2016. The “natitas” are cared for and decorated by faithful who use them as amulets believing they serve as protection, the tradition marks the end of the Catholic All Saints holiday, but is not recognized by the Catholic church. (Photo by Juan Karita/AP Photo)