Denver Broncos cheerleaders during the third quarter. The Denver Broncos played the Kansas City Chiefs at Sports Authority Field at Mile High in Denver, Colo. on September 14, 2014. (Photo by Aaron Ontiveroz/The Denver Post via Getty Images)

Participants wearing masks during a hazy day at the Beijing International Marathon in front of Tiananmen Square, in Beijing, October 19, 2014. (Photo by Reuters/Stringer)

Injured horses huddle together in Oklahoma City on Monday. (Photo by Chris Landsberger/The Oklahoman)

Winner of the Sandow bodybuilding competition, Mr. Murray. (Photo by Reinhold Thiele/Thiele/Getty Images). Circa 1905

Two elderly men smoking pipes of opium on a terrace in Korea. (Photo by Bert Hardy/Picture Post/Getty Images). August 1950

In this May 14, 2016 photo, children wearing their school backpacks climb on a cliff using a bamboo ladder on their way home from school in Zhaojue county, southwest China's Sichuan province. A village in China's mountainous west where schoolchildren must climb an 800-meter (2,625-foot)-high bamboo ladder secured to a sheer cliff face may get a set of steel stairs to improve it's safety. (Photo by Chinatopix via AP Photo)

A man lies in the sea grass at a beach on July 18, 2016 in Qingdao, Shandong Province of China. The enteromorpha prolifera spread on the beaches in Qingdao and were under clearing. (Photo by VCG/VCG via Getty Images)

People walk passed sculptures by Chinese artist Minjun Yue on a street outside a museum in Beijing, China on July 5, 2018. (Photo by Nicolas Asfouri/AFP Photo)