A competitor walks on tightrope during a performance in Taizhou, Zhejiang Province, China, May 7, 2016. (Photo by Reuters/China Daily)

Ashley Ward kayaks down a flooded street that has been inundated with water from Hurricane Harvey on August 27, 2017 in Houston, Texas. Harvey, which made landfall north of Corpus Christi late Friday evening, is expected to dump upwards to 40 inches of rain in areas of Texas over the next couple of days. (Photo by Scott Olson/Getty Images)

A Somali Armed Forces member carries her ammunition during fighting between the military and police backed by intelligence forces in the Dayniile district of Mogadishu, Somalia September 16, 2017. (Photo by Feisal Omar/Reuters)

Antonina Yermokhina, 86, does physical exercises during her daily training session on the embankment of the Yenisei River in the Siberian town of Divnogorsk, Russia November 13, 2017. (Photo by Ilya Naymushin/Reuters)

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)

Thailand's Puttita Supajirakul is down on the court after a point during a women's doubles badminton match against the Netherlands at the 2016 Summer Olympics in Rio de Janeiro, Brazil, August 11, 2016. (Photo by Kin Cheung/AP Photo)

Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

This picture taken on February 16, 2017 in Fangshan village in China's coastal province Fujians, shows a villager performing the “eating flowers” ritual. Villagers in eastern China have a unique way of washing away the taint of evil spirits – by bathing in a shower of scorching sparks. (Photo by Johannes Eisele/AFP Photo)