A grave cleaner holds up a skull during exhumation works at the Cemetery General in Guatemala City May 24, 2013. If a lease on a grave has expired or not been paid, grave cleaners will break open the crypts to remove and rebury the bodies. (Photo by Jorge Dan Lopez/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)

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 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)

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 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)

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)

A general view of Stonehenge during the annual Perseid meteor shower in the night sky in Salisbury Plain, southern England August 13, 2013. The Perseid meteor shower is sparked every August when the Earth passes through a stream of space debris left by comet Swift-Tuttle. Picture taken using a long exposure. (Photo by Kieran Doherty/Reuters)