A tourist poses on the glass-bottom bridge at Zhangjiajie Grand Canyon on August 20, 2016 in Zhangjiajie, Hunan Province of China. The Zhangjiajie Grand Canyon's glass-bottomed bridge welcame its trial operation on Saturday and about 8,000 tourists crowded to view the grand glass bridge. (Photo by VCG/VCG via Getty Images)

A colorful sky at sunset over the snowy mountains in Immenstadt, Bavaria, Germany, 20 November 2014. Cloudy weather is forecast in the region on 21 November. (Photo by Karl-Josef Hildenbrand/EPA)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

Iraqi teenagers swim in waste water from the nearby Tuweitha nuclear facility near Baghdad, Iraq on May 28, 2003. Iraqis are consuming contaminated water unaware of the dangerous pollutants that can cause severe ill health. (Photo by Damir Sagolj/Reuters)

Sunrise over a moor viewed from Littaford Tor, Dartmoor, UK, 2016. Autumn visits the windswept moors and granite tors of Dartmoor earlier than the rest of the south-west. While there aren’t many trees here, autumn shades appear in golden ferns and tan heather. Littaford Tors, near Two Bridges and a mile from Princetown, is a short walk and can be combined with a visit to the adjacent Wistman’s Wood. (Photo by Stuart Holmes)

Visitors look on as a man (front) inserts two live snakes through his nose and mouth during a performance at an amusement park to celebrate the 65th anniversary of the founding of the People's Republic of China and the 7-day national day holiday, in Jinhua, Zhejiang province October 1, 2014. (Photo by Reuters/Stringer)

A group of youngsters dressed as ghouls and zombies for Halloween parade in downtown Lisbon, Portugal, Friday, October 31, 2014. (Photo by Francisco Seco/AP Photo)

Migrants seeking asylum in the U.S., who returned to the Mexican side of the border to avoid deportation, play soccer in a makeshift migrant camp in Braulio Fernandez Ecological Park in Ciudad Acuna, Mexico, September 22, 2021. (Photo by Go Nakamura/Reuters)