A giant river otter, the world's largest otter species, looks out of its enclosure at the newly completed River Safari in Singapore, on March 25, 2013. (Photo by Wong Maye-E/Associated Press)

Chinese aids activists hand out condoms in a subway train in Wuhan, central China's Hubei province on December 1, 2014. The World Health Organization issued a call to action to China on December 1, 2014 over HIV/AIDS as government figures said nearly half a million people are living with the disease or its precursor, with hundreds of thousands more thought to be undiagnosed. (Photo by AFP Photo)

A person poses on the track during a fashion competition at the Durban July horse racing event in Durban, South Africa, July 2, 2016. (Photo by Rogan Ward/Reuters)

Soccer player David Beckham (C) with Cruz Beckham (L) and Romeo Beckham (R) get slimed onstage during Nickelodeon Kids' Choice Sports Awards 2014 at UCLA's Pauley Pavilion on July 17, 2014 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)

Green algae sits on a beach in Kuwait City, Kuwait, 28 February 2017. The formation of green algae is a normal phenomenon that occurs every year at the shores of Kuwait. (Photo by Raed Qutena/EPA)

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)

“7584 Fish”. On a windy day right after a Cyclone passed the far northern Great Barrier Reef i took some friends out to the reef. Never before i saw that many glass fish on this particular coral “bommie”. Just when i setup my camera, this Napoleon Wrasse swam right through the school of fish building a living frame. Photo location: Cairns, Great Barrier Reef, Flynn Reef, Australia. (Photo and caption by Christian Miller/National Geographic Photo Contest)

Jing Li (L) and her husband Ke Xu wear Tibetan traditional costumes as they pose for their wedding photos in front of Tibetan prayer flags at the Nianqing Tanggula mountain pass in the Tibet Autonomous Region, China November 18, 2015. Jing, 22, and her husband Ke Xu, 23, both from Shiyan in northwestern Hubei province live in Tibet for three year. The couple married last month. (Photo by Damir Sagolj/Reuters)