Members of the SubCielo company perform during the fifth annual Puerto Rico Circo Fest in San Juan, Puerto Rico, Saturday, March 10, 2018. The festival is held simultaneously in several spots on the streets of the Old San Juan city on March 10–11. (Photo by Ricardo Arduengo/AFP Photo)

Racegoers during Ladies Day of the 2018 Cheltenham Festival in Cheltenham, England on March 14, 2018. (Photo by Graham Stone/Rex Features/Shutterstock)

An ethnic Lisu man dances barefoot on hot charcoal embers to celebrate the annual Knife Pole Festival in Luzhang township of Nujiang Lisu Autonomous Prefecture in Yunnan province, China, March 29, 2018. (Photo by Aly Song/Reuters)

This photo taken on April 7, 2018 shows Rohingya refugee attending a demonstration of elephant resistance arranged by the UNHCR and IUCN at the Kutupalong refugee camp in Ukhia, Bangladesh. The purpose of the training day is sobering – a dozen Rohingya have been killed by wild elephants whose habitat has been consumed by Kutupalong refugee camp. (Photo by Munir Uz Zaman/AFP Photo)

Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Angel Hall, 22, (C) and Bri Artis, 21, (R) dance in a silent disco on the fourth and final day of the Firefly Music Festival in Dover, Delaware on June 17, 2018. (Photo by Mark Makela/Reuters)

A member of the Pakistani Anti-Narcotic Force (ANF) takes a selfie beside a pile of burning drugs and liquor during a ceremony at the Kacha Ghari army firing range, on the outskirts of Peshawar on October 16, 2018, after the contraband was seized in raids across the province. (Photo by Abdul Majeed/AFP Photo)

Spectators pose for a selfie before the running of the Melbourne Cup at the Flemington Racecourse in Melbourne, Australia, Tuesday, November 6, 2018. (Photo by Andy Brownbill/AP Photo)