Couples take part in a competition during a mass wedding of 64 doctoral student couples at Harbin Institute of Technology, a university in Harbin, Heilongjiang province, China, June 4, 2017. (Photo by Reuters/Stringer)

A participant, surrounded by red chilli peppers, takes part in a chilli-eating competition at a hot spring in Yichun, Jiangxi province, China on December 9, 2018. (Photo by Chen Fei/China News Service via Reuters)

2016 Rio Olympics, Rugby, Women's Semifinals Britain vs New Zealand, Deodoro Stadium, Rio de Janeiro, Brazil on August 8, 2016. Portia Woodman (NZL) of New Zealand tackles Claire Allan (GBR) of United Kingdom. (Photo by Phil Noble/Reuters)

Firefighters work to put out flames during a wildfire in Sokcho, South Korea, April 5, 2019. South Korea grappled with the massive blaze that roared through forests and cities along the eastern coast, declaring a national emergency and mobilizing all available resources to bring the inferno under control. (Photo by Yonhap via Reuters)

A man with a cap on his face sleeps on a floor at the Mahabat Khan Mosque in Peshawar, Pakistan on March 4, 2019. (Photo by Fayaz Aziz/Reuters)

The hard-worked hands of Jacaba Coaquira, 80, holding the green beans she grew on her land. This year the production of her land was affected by lack of rain and early cold weather that froze the crops before they finished growing. Santiago de Okola, Bolivia. (Photo by Renée C. Byer/Living on a Dollar a Day)

A female bodybuilder apples oil to another performer backstage before an amateur competition in the Israeli city of Dimona, in this April 3, 2014 file photo. (Photo by Finbarr O'Reilly/Reuters)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)