A petitioner with her grievances written on her clothes walks along a street in Beijing Tuesday, December 22, 2015. After months behind bars, Pu Zhiqiang, one of China's most prominent human rights lawyers, left a detention center Tuesday after receiving a suspended prison sentence in a case involving online comments critical of the ruling Communist Party. (Photo by Ng Han Guan/AP Photo)

A volcanic eruption at Mount Etna’s Vorgaine crater in Sicily, Italy on December 3, 2015. (Photo by Marco Restivo/Barcroft Media)

A competitor loses his shoe during the annual race on high heels during Gay Pride celebrations in the quarter of Chueca in Madrid, Spain, June 30, 2016. (Photo by Susana Vera/Reuters)

A flock of sheep huddles together while snow spindrift is whipped up by strong winds in Swaledale, North Yorkshire, UK on March 17, 2017. (Photo by Paul Kingston/NNP North News & Pictures Ltd)

A robot is seen on Mount Etna, Italy on July 4, 2017. Mount Etna, in Sicily, is a test bed for the approximately three-foot high, four-wheeled machine ahead of a future mission to the moon. It is being conducted by the German Aerospace Centre, the agency which runs Germany's space programme. (Photo by Antonio Parrinello/Reuters)

These stunning images show the beauty and drama of Mother Nature at work. Captured deep in heart of the Danakil Desert in East Africa, the images show the acid pools near the Erta Ale volcano. Pools of brightly colored acid can be seen amid the dramatic blast of volcanic ash. The photos were taken by Neta Dekel, an Israeli photographer. He the acid pools were one of the most extraordinary sights he had ever seen. (Photo by Neta Dekel/Caters News Agency)

A ballet dancer brushes on blush as she prepares for a street ballet performance in Mexico City, Saturday, July 28, 2018. In this sprawling megalopolis notorious for its clogged streets, a theater company sent out tutu-clad dancers out to delight motorists at snarled intersections with snippets from ballet classics like “The Nutcracker” and “Swan Lake” all in the 58 seconds it takes for the light to go from red to green. (Photo by Emilio Espejel/AP Photo)

Pod of dolphins surf effortlessly through the waves in the wild traveling at speeds up to 20 mph. (Photo by Greg Huglin)