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)

Nigel Lamb from Great Britain, left, leading Juan Velarde of Spain, centre, and Martin Šonka of Czech Republic in the FAI Red Bull air race, Isle of Wight, UK on August 9, 2016. (Photo by Joerg Mitter/Red Bull/Global New/PA Wire)

Women perform under black fabric during a street performance in Pristina on October 6, 2017 against sexual harassments in Kosovo. (Photo by Armend Nimani/AFP Photo)

A man steers with his legs while riding a motorcycle on a road in Vietnam's northern Hoa Binh province, outside Hanoi, October 15, 2015. (Photo by Reuters/Kham)

Young man making the O.K. sign. (Photo by George Marks/Retrofile/Getty Images). Circa 1950s

A woman walks behind the installation “Wandering boy is forever attractive” (1985) by Tetsumi Kudo during the press preview at the exhibition “Tetsumi Kudo – Retrospective” in the Fridericianum in Kassel, Germany, Friday, September 23, 2016. The exhibition offers an in-depth, comprehensive view of works by the Japanese artist Kudo. It starts on Sept. 25, 2016 and lasts until Jan. 1, 2017. (Photo by Jens Meyer/AP Photo)

Michal Navratil of the Czech Republic performs after the men's 27 meter high dive final at the Swimming World Championships in Kazan, Russia, Wednesday, August 5, 2015. (Photo by Denis Tyrin/AP Photo)

In this Saturday, September 5, 2015, photo, three women in costumes look at sea life swimming above them during a private party held at the Georgia Aquarium as part of Dragon Con in Atlanta. The convention draws fans from around the country to take part in sci-fi and fantasy costume contests, a massive parade through downtown Atlanta and educational seminars about science and costume making. (Photo by Ron Harris/AP Photo)