A Hawaiian cleaner wrasse provides its cleaning services to a yellowfin goatfish in a reef community off the Big Island in Hawaii. Cleaner species help rid their hosts of ectoparasites, dead tissue, bacteria and fungi. Studies have shown cleaning to play a vital role in keeping many reef ecosystems healthy. (Photo by Marty Snyderman/Caters News Agency)

The worlds largest cruise ship, the 361 metres long, Harmony of the Seas, arrives in port for her mayden voyage, in Southampton, Britain May 17, 2016. (Photo by Peter Nicholls/Reuters)

People gather at the site of a train derailment near Beni Suef, Egypt, Thursday, February 11, 2016 that injured dozens of people were injured as it was traveling north toward Cairo. Railroad accidents due to negligence are common in Egypt. Egyptians have long complained that the government has failed to deal with the country's chronic transport problems. (Photo by Samer Abdallah/AP Photo)

Two women wearing nun outfits drink beer while watching the 2014 Tim Hortons Brier curling championships in Kamloops, British Columbia in this March 8, 2014 file photo. Although some people might conclude that a curling event could produce a dull atmosphere, it is actually far from it. Some of the most energetic and loyal fans are committed to showing their colours at tournaments around the world. There was a lull in the games that were being held on this day and I remember spotting these nuns sitting in their seats earlier. Although them just sitting there didn't produce a picture, I kept my eye on them for the entire match. As soon as I spotted them with beer in their hands, I slowly turned my camera towards them and waited for them to take a drink. One of the challenges of shooting this image was to not have everyone notice me taking the photo. I had a longer lens on and was right in the middle of the rink. I slowly turned my lens, not to make my intentions too obvious, and waited until they drank from their beers together. (Photo and caption by Ben Nelms/Reuters)

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 participant poses with his laptop during the 33rd Chaos Communication Congress on its opening day on December 27, 2016 in Hamburg, Germany. The annual event is bringing together 12,000 computer hackers and activists who will meet over the next four days to share expertise and discuss topics related to the society and the digital world. (Photo by Morris MacMatzen/Getty Images)

Athlets run during the women's 3000 meter steeplechase at the International Athletics Meeting in Lucerne, Switzerland, 14 June 2016. (Photo by Alexandra Wey/EPA)

Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)