Participants pose as they take part in a bodybuilding and fitness event named “China Fit”, in Beijing, China, June 15, 2016. (Photo by Reuters/Stringer)

This photo provided by Steamboat Ski Resort shows hot air balloons that visitors can tour in above the town and mountains in Steamboat Springs, Colo. Wild West Adventures offer continental breakfast, champagne ceremony with flight certificates and courtesy pick-up are included. (Photo by Larry Pierce/AP Photo/Steamboat Ski Resort)

A woman poses next to a giant mining truck at the entrance of the Dakar Rally camp in Calama, Chile. The truck operates in copper mines near the city. (Photo by Victor R. Caivano/Associated Press)

A woman poses for a photograph in front of a 3D painting at HK 3D Museum in Hong Kong June 26, 2014. (Photo by Tyrone Siu/Reuters)

Protesters take part in “Artists Take Fight Against Police Murders” in New York's Times Square August 13, 2015. (Photo by Brendan McDermid/Reuters)

In this Wednesday, April 12, 2017, photo, waitresses wait outside a restaurant in Pyongyang, North Korea. A generational divide is quietly growing in North Korea, often hidden behind relentless propaganda. On the streets there are young women in not-quite mini-skirts and teenage boys with baseball hats cocked sideways, K-pop style. (Photo by Wong Maye-E/AP Photo)

School teachers and staff members take part during an active shooter training at James I. O'Neill High School in Highland Falls, New York, U.S., December 12, 2017. (Photo by Eduardo Munoz/Reuters)