A 10-year-old pet goldfish named George undergoes veterinarian Tristan Rich's scalpel to remove a life-threatening head tumor in this handout picture taken September 11, 2014 and provided to Reuters by the Lort Smith Animal Hospital in Melbourne, Australia. In a 45-minute long procedure described by Rich as “fiddly”, the fish was sedated by water laced with anaesthetic, the tumour removed and the wound sealed with tissue glue followed by antibiotics and painkillers. (Photo by Reuters/Lort Smith Animal Hospital)

Hair stylist Marcelo Avatte (R) prepares to fit Isidora Serrano, a 14-year-old who lost her hair due to chemotherapy to treat her bone cancer, with a natural hair wig in the cancer ward of the Luis Calvo Mackenna Hospital in Santiago, October 23, 2014. The wigs, handmade by Italian-Chilean hair stylist Marcelo Avatte and his team, have helped the children regain their self-esteem and confidence during cancer treatment. Renowned for making customised wigs, Avatte has donated more than 300 wigs since 2009 and says he was motivated to begin the project by the pain he felt when his own son lost his hair during chemotherapy. (Photo by Rodrigo Garrido/Reuters)

A riot policeman uses a baton to hit a rioting University of Nairobi student in Kenya's capital Nairobi, in this May 20, 2014 file photo. (Photo by Noor Khamis/Reuters)

A man transports the carcass of a car on a two- wheeled carriage in a neighborhood in Abobo, a suburb of Abidjan, Côte d’Ivoire on December 1, 2017. (Photo by Issouf Sanogo/AFP Photo)

Residents in fox makeup participate in the Oji Fox parade to thank the outgoing and welcome the incoming year at the Oji Inari shrine in Tokyo late on December 31, 2017. (Photo by Toshifumi Kitamura/AFP Photo)

A tourist clad in Japanese kimono takes a picture in front of s portrait shop in Tokyo's Asakusa district, Thursday, February 15, 2018. Asakusa is a popular district four tourists in the capital. (Photo by Shizuo Kambayashi/AP Photo)

Train attendants take part in a parade training as they visit the national flag guard during a patriotic education event ahead of the 90th anniversary of the founding of the Chinese People's Liberation Army (PLA) in Beijing, China July 25, 2017. (Photo by Reuters/China Stringer Network)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)