An AH-64D Apache attack helicopter flies in front of a wall of fire during the South Carolina National Guard Air and Ground Expo at McEntire Joint National Guard Base, South Carolina, U.S. on May 6, 2017. (Photo by Jorge Intriago/Reuters/Courtesy Air National Guard)

A soldier from the South Korean army special forces breaks stone plates with her head during a martial arts demonstration for Memorial Day at Korea War Memorial Museum in Seoul, South Korea, Monday, June 6, 2016.(Photo by Ahn Young-joon/AP Photo)

Metropolitan Transit Authority (MTA) Police Officer Keith Flood trains with his K-9 partner Doc, a German Shepherd, inside the “warehouse room” at the new MTA Police Department Canine Training Center in Stormville, New York, U.S., June 6, 2016. (Photo by Mike Segar/Reuters)

Buddhist monks take shelter under a tarpaulin sheet to protect themselves from the rain as they attend the birthday celebrations of the Tibetan spiritual leader the Dalai Lama (unseen) at Drepung Loseling Monastery in Mundgod, in the southern state of Karnataka, India, July 6, 2016. (Photo by Abhishek N. Chinnappa/Reuters)

2016 Rio Olympics, Weightlifting, Final, Women's 48kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 6, 2016. Beatriz Piron (DOM) of Dominican Republic fails to lift. (Photo by Kai Pfaffenbach/Reuters)

Chinese tourists watch storm clouds moving along the coast towards the city of Sydney, Australia, November 6, 2015. Powerful storms swept across the city on Friday, with the Australian Bureau of Meteorology issuing a warning for severe thunderstorms with large hailstones, heavy rainfall and damaging winds, local media reported. (Photo by David Gray/Reuters)

A staff member (R) looks on next to a cake, which was baked in the shape of a muscular man, for customers to try for free during a promotional event of a cake store in Shenyang, Liaoning province, China, December 6, 2015. (Photo by Reuters/Stringer)

The team from France performs their Free Routine during the Synchronized Swimming Olympic Games Qualification Tournament at the Maria Lenk Aquatics Center in Rio de Janeiro, Brazil on March 6, 2016. The tournament is also a test event for the Rio 2016 Olympics. (Photo by Sergio Moraes/Reuters)