A DC-10 air tanker delivers flame retardant to the Blue Cut fire in Wrightwood, Calif., Wednesday, August 17, 2016. A wildfire with a ferocity never seen before by veteran California firefighters raced up and down canyon hillsides, instantly engulfing homes and forcing thousands of people to flee, some running for their lives just ahead of the flames. (Photo by Alex Gallardo/AP Photo)

A visitor jumps for a photograph on the world's highest and longest glass-bottomed bridge above a valley in Zhangjiajie in China's Hunan Province on August 21, 2016. The bridge, which opened to the public on a trial basis on Saturday, spans 430 meters (1,410 feet) and rises about 300 meters (984 feet) above a valley in a scenic zone, making it the world's highest and longest glass-bottomed bridge according to Chinese state media. (Photo by Fred Dufour/AFP Photo)

People ride on a truck as they return to their families ahead of the Eid al-Adha festival in Khartoum September 11, 2016. (Photo by Mohamed Nureldin Abdallah/Reuters)

A dog, at the behest of his owner, rides a skatebaord on April 3, 2017 in Berlin, Germany. The dog's owner, who looked like he might be homeless, coaxed the dog to ride the skatebaord and asked passersby who stopped to watch for money. (Photo by Sean Gallup/Getty Images)

A woman spends her time outdoors to observe the ancient festival of Sizdeh Bedar, an annual public picnic day on the 13th day of the Iranian new year, at the Tochal mountainous area northern Tehran, Iran, Sunday, April, 2, 2017. Sizdeh Bedar, which comes from the Farsi words for “thirteen” and “day out”, is a legacy from Iran's pre-Islamic past that hard-liners in the Islamic Republic never managed to erase from calendars. (Photo by Ebrahim Noroozi/AP Photo)

British model Jourdan Dunn arrives for the premiere of “The Killing of a Sacred Deer” during the 70th annual Cannes Film Festival, in Cannes, France, 22 May 2017. The movie is presented in the Official Competition of the festival which runs from 17 to 28 May. Dress by Elie Saab Haute Couture. (Photo by Julien Warnand/EPA)

Geisha women parade down the street to Asakusa Shrine in the compound of Sensoji Temple Friday, May 19, 2017, in Tokyo prior to the annual Sanja Festival, one of the three major festivals in Tokyo. (Photo by Eugene Hoshiko/AP Photo)

A Chinese People's Liberation Army soldier marches with members of an honor guard as they prepare for a welcome ceremony for visiting Luxembourg's Prime Minister Xavier Bettel outside the Great Hall of the People in Beijing, Monday, June 12, 2017. (Photo by Andy Wong/AP Photo)