Children play on a donkey cart belonging to an elderly Afghan refugee sleeping on a roadside on the outskirts of Islamabad, Pakistan, Wednesday, February 18, 2015. (Photo by Muhammed Muheisen/AP Photo)

A professional bull rider participates in a bull riding exhibition at the premiere of “The Longest Ride” at the TCL Chinese Theatre on Monday, April 6, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

Period-costumed actors participate in the 150th anniversary re-enactment of the surrender of General Robert E. Lee to General Ulysses S. Grant at the Museum of Confederacy in Appomattox, Virginia, April 9, 2015. (Photo by Jay Paul/Reuters)

A visitor looks at a creation at the Artemide space during Milan Design Week, April 14, 2015. The Milan Design Week will be held until April 19. (Photo by Stefano Rellandini/Reuters)

A model walks down the runway during the Fashion Palette Miami Australian Swim Show during Miami Swim Week, Sunday, July 15, 2018, in Miami Beach, Fla. (Photo by Lynne Sladky/AP Photo)

British tourist participates in a crab race at the annual Tobago Heritage Festival, at Buccoo Integrated Facility, in Tobago island, Trinidad and Tobago on July 29, 2018. (Photo by Andrea De Silva/EPA/EFE)

Two brown bears bathe in their enclosure at the Wildpark Poing in Poing, Germany, Wednesday, August 8, 2018. (Photo by Lino Mirgeler/Deutsche Presse-Agentur via AP Photo)

A woman touches a robot at the 2018 World Robot Conference in Beijing on August 15, 2018. The conference will be held from 15 to 19 August and will include a conference on robotics, an exhibition and a robot competition with the participation of robotics enterprises to showcase their robot products. (Photo by Wang Zhao/AFP Photo)