Al Fursan, the UAE Air Force aerobatic display team, perform during the opening of the Dubai Airshow in United Arab Emirates, Sunday, November 8, 2015. Dubai Airshow took off today to a slow start amid little expectations of major orders to match the multi-billion-dollar sales generated at the last edition of the biennial fair. (Photo by Kamran Jebreili/AP Photo)

In this November 21, 2015 photo, Camila Lopez Rivas, 14, poses for portraits on a beach in Havana, Cuba, as an assistant lifts the train of her dress to make it look like its flying in the wind. Camila lives in Miami, the daughter of a truck driver who left Cuba when she was a baby. She doesn't remember the island, but wanted to return for the photographs and videos that Latin American girls typically take for their 15th birthdays. (Photo by Ramon Espinosa/AP Photo)

A visitor watches the exhibit “Enchanted: Forest of Light” at Descanso Gardens in La Canada Flintridge, California U.S., December 9, 2016. (Photo by Mario Anzuoni/Reuters)

A woman worker prepares her stall at Tanah Abang textile market in Jakarta, Indonesia January 11, 2017. (Photo by Fatima El-Kareem/Reuters)

Tea garden workers carry sacks of tea leaves at Fatikchera tea garden estate on the outskirts of Agartala, India, May 10, 2016. (Photo by Jayanta Dey/Reuters)

Young children at a Bristol, Great Britain health centre unsure of the benefits of sun-lamps and the special glasses that must be worn, July 1948. The health centre was part of the newly introduced free National Health Service. (Photo by Popperfoto/Getty Images)

Indian policemen carry the body of one of their colleagues killed in a rebel attack in the town of Dinanagar, in the northern state of Punjab, India, Monday, July 27, 2015. Indian forces fought an extended gunbattle Monday with militants who attacked a moving bus and stormed into a police station in a northern town bordering Pakistan. (Photo by Channi Anand/AP Photo)

First graders of a cadet's lyceum attend a ceremony to mark the start of the new school year in Kiev, Ukraine, September 1, 2015. September 1 marks the start of a new academic year for students in Ukraine.(Photo by Valentyn Ogirenko/Reuters)