Performers line up during the closing ceremony of the 2014 Winter Olympics, Sunday, February 23, 2014, in Sochi, Russia. (Photo by Darron Cummings/AP Photo)

Western lowland gorilla Kijivu holds her newborn baby at the Prague Zoo in the Czech Republic. (Photo by Isifa/Getty Images)

Coloured X-ray of a barn owl. A physicist has used X-ray to create an extraordinary collection of artwork. Arie van't Riets pictures reveal birds, fish, monkeys and flowers in an incredible new light. The 66-year-old, from Bathmen in the Netherlands, began X-raying flowers as a means to teach radiographers and physicians how the machine worked. But after adding a bit of colour to the pictures, the retired medical physicist realised the potential for an exciting new collection of art. (Photo by Arie van't Riet/Barcroft Media)

A General Atomics MQ-9 Reaper stands on the runway during “Black Dart”, a live-fly, live fire demonstration of 55 unmanned aerial vehicles, or drones, at Naval Base Ventura County Sea Range, Point Mugu, near Oxnard, California July 31, 2015. (Photo by Patrick T. Fallon/Reuters)

A model presents a creation during the Biofashion show, which features designs made from plants, recycled and natural materials, in Cali, Colombia, November 19, 2016. BioFashion is an environmental initiative that seeks to create awareness about the preservation and management of natural resources where new designers develop dresses made with living plants, flowers and organic elements. (Photo by Jaime Saldarriaga/Reuters)

Muay Thai boxer Nong Rose Baan Charoensuk, who is transgender, trains at a gym in Buriram province, Thailand, July 3, 2017. Born Somros Polchareon, Rose said she identified as a woman at an early age and began wearing makeup and a sports bra in the ring.(Photo by Athit Perawongmetha/Reuters)

Residents wade through flood waters from Tropical Storm Harvey in Beaumont Place, Houston, Texas on August 28, 2017. Houston was still largely paralyzed Monday, and there was no relief in sight from the storm that spun into Texas as a Category 4 hurricane, then parked itself over the Gulf Coast. (Photo by Jonathan Bachman/Reuters)

Miners pulling up lazy tourists to the rim of Kawah Ijen (Ijen Volcano), East Java, Indonesia on September 21, 2017. They will earn as much as they would bring down a load of sulfur. Nomadic Explorer, Cultural Lifestyle Photographer Claudio Sieber captured striking images of miners working at Ijen volcanic range in East Java, Indonesia. The sulphur miners risk their lives daily as they climb the active volcano carrying heavy loads, which they sell to sugar refineries. (Photo by Claudio Sieber/Barcroft Images)