Civilians, who fled the violence in Manbij city, arrive to the southeastern rural area of Manbij, in Aleppo Governorate, Syria June 19, 2016. (Photo by Rodi Said/Reuters)

Young woman, 20+, with goose bumps, standing on the beach, Niendorf at the Baltic Sea, Schleswig-Holstein, Germany, Europe on September 1, 2016. (Photo by Alamy Stock Photo)

Children play football in Bujumbura, Burundi on March 19, 2015. (Photo by Carl de Souza/AFP Photo)

The Breitling DC-3, HB-IRJ, plane fly escorted by Italian Air Force's aerobatic demonstration team, the Frecce Tricolori, during the last stage of its world tour two days ahead of the International Sion Air Show, in Sion, Switzerland, 13 September 2017. From March to September 2017, the Breitling DC-3 from 1940 has done a grand world tour in several stages, over 28 countries and flies 50000km, an amazing accomplishment for this legendary plane that will be celebrating its 77th birthday. (Photo by Christian Merz/EPA/EFE)

Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

A couple ride a motorcycle along a street during snow in Altay, Xinjiang Uighur Autonomous Region, China, November 8, 2015. Picture taken November 8, 2015. (Photo by Reuters/Stringer)

A girl stands against strong wind caused by Typhoon Mangkhut at a pier on the waterfront of Victoria Habour Hong Kong, Sunday, September 16, 2018. Hong Kong and southern China hunkered down as strong winds and heavy rain from Typhoon Mangkhut lash the densely populated coast. The biggest storm of the year left at least 28 dead from landslides and drownings as it sliced through the northern Philippines. (Photo by Vincent Yu/AP Photo)

In this undated photo made available by journal Nature on January 15, 2014, a northern bald ibis (Geronticus eremita) flies in Tuscany, Italy. A new study released Wednesday, January 15, 2014 says the birds choreograph the flapping of their wings, getting a boost from an updraft of air in the wake of the flapping wings by flying behind the first bird and off to the side. When a flock of birds take advantage of these aerodynamics, they form a V. (Photo by Markus Unsöld/AP Photo)