Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

Protesting university students flee as police fire stun grenades outside Parliament in Cape Town, South Africa, Wednesday October 21, 2015. The protests are part of a wave of nationwide protests that have shut down many South Africa universities, which say they are struggling with higher operational costs as well as inadequate state subsidies. (Photo by AP Photo)

A street performer jumps in the air inside Central Park as the colors of autumn become more prevalent in New York, October 29, 2015. (Photo by Lucas Jackson/Reuters)

A woman plays with a kitten inside of a line house in downtown Shanghai April 12, 2015. (Photo by Carlos Barria/Reuters)

Flying pigeons pass over Nepalese street vendors near the earthquake damaged UNESCO World Heritage Site, Durbar Square in Kathmandu on May 20, 2015. Nearly 8,500 people have now been confirmed dead in the disaster, which destroyed more than half a million homes and left huge numbers of people without shelter with just weeks to go until the monsoon rains. (Photo by Ishara S. Kodikara/AFP Photo)

Russia's synchronised swimming duet Aleksandr Maltsev (L) and Darina Valitova compete in the Mixed Duet Technical preliminary during the synchronised swimming competition at the 2015 FINA World Championships in Kazan on July 25, 2015. (Photo by Christophe Simon/AFP Photo)

A woman poses next to two mailboxes along a street in Taipei on August 11, 2015 that were reportedly bent by strong winds brought by Typhoon Soudelor over the weekend. The two iron mailboxes have become an unlikely attraction, drawing thousands of snap-happy visitors and have even become a backdrop to a wedding photo shoot. The typhoon, which hit in the early hours of August 8 and was billed as the most powerful typhoon this year, uprooted trees, brought down electricity poles, knocking out power to a record 4.3 million households, while leaving eight dead and four missing. (Photo by Benjamin Yeh/AFP Photo)

Aquarium visitors attend a dinner party in an underwater tunnel in Tianjin, China on September 15, 2016. Tianjin Haichang Polar Ocean World opened in the city of Tianjin, southeast of Beijing, in 2010. It gives visitors a chance to see more than 150 large animals from the Arctic and Antarctic regions, including polar bears. (Photo by Feature China/Barcroft Images)