Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)

Hot air balloons are prepared for a flight as others take off during an international hot air balloon festival at Maayan Harod National park in northern Israel September 30, 2015. (Photo by Baz Ratner/Reuters)

Models prepare backstage ahead of the Strateas.Carlucci show at Mercedes-Benz Fashion Week Australia 2015 at Carriageworks on April 13, 2015 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)

A model prepares backstage at The Blonds fashion show during Fall 2016 MADE Fashion Week at Milk Studios on February 17, 2016 in New York City. (Photo by Monica Schipper/Getty Images)

Dancers from the School of American Ballet Chloe Ellis (R) and Amarra Hong (L) prepare for a performance at the Queens Theatre in the Queens borough of New York February 28, 2016. (Photo by Shannon Stapleton/Reuters)

A C-17 Globemaster III crew prepares an air refueling mission September 27, 2012, at Joint Base Charleston, S.C. (Photo by Airman 1st Class Matthew J. Bruch/U.S. Air Force photo)

Yawalapiti children play during the preparations for the celebration of “quarup”, a ritual held to honor in death a person of great importance to them, in the Xingu National Park, Mato Grosso State, May 7, 2012. (Photo by Ueslei Marcelino/Reuters)

Assi Mbengue nibbles as she prepares for the start of Las Palmas' Carnival Queen ceremony in Las Palmas, Spanish Canary Island of Gran Canaria, February 24, 2017. (Photo by Borja Suarez/Reuters)