People walk on the installation “The Floating Piers” on Lake Iseo by Bulgarian-born artist Christo Vladimirov Yavachev, known as Christo, at the installation's last weekend near Sulzano, northern Italy, July 2, 2016. (Photo by Wolfgang Rattay/Reuters)

A view of the Sheikh Zayed highway in Dubai and some high rise buildings, November 8, 2007. (Photo by Steve Crisp/Reuters)

A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

Cocoa pods are seen on the ground at a farm in Ile-Oluji village in Ondo state, southwest Nigeria March 29, 2016. (Photo by Akintunde Akinleye/Reuters)

A man poses for a picture to show his rings of gold, silver and bronze on his fist in Zamfara, Nigeria April 21, 2016. (Photo by Afolabi Sotunde/Reuters)

A woman stands in front of graffiti depicting Venezuela's late former President Hugo Chavez, right, and revolutionary hero Simon Bolivar, in downtown Caracas, Venezuela, Wednesday, October 25, 2017. (Photo by Rodrigo Abd/AP Photo)

Animal rights activist, stained with fake blood, perform during a protest against the use of animal skins in the clothes and fashion industry, in Madrid, Sunday, December 10, 2017. (Photo by Francisco Seco/AP Photo)

Max Gold, 20, of NYC, cruises on his skateboard as thousands gather on the National Mall for the March for Science on Saturday, April 22, 2017, in Washington, DC. Activists and scientists descend on the nation's capital to rally for environmental causes and government policies rooted in scientific research as part of the Earth Day and March for Science rallies. (Photo by Jahi Chikwendiu/The Washington Post)