Military vehicles surround a wreckage of a trolleybus, in Volgograd, Russia, Monday, December 30, 2013. A bomb blast tore through a trolleybus in the city of Volgograd on Monday morning, killing at least 10 people a day after a suicide bombing that killed at least 17 at the city's main railway station. Volgograd is about 650 kilometers (400 miles) northeast of Sochi, where the Olympics are to be held. (Photo by Denis Tyrin/AP Photo)

Tibetan boys dressed in traditional attire take part during a function organised by the Tibetan Refugee Community in Nepal,commemorating the 25th Anniversary of the Nobel Peace Prize conferment to exiled Tibetan spiritual leader Dalai Lama and the 66th International Human Rights Day in Kathmandu December 10, 2014. Nepal ceased issuing refugee papers to Tibetans in 1989 and recognizes Tibet to be a part of China. (Photo by Navesh Chitrakar/Reuters)

A worker paints the Amazon Tall Tower Observatory (ATTO) in Sao Sebastiao do Uatuma in the middle of the Amazon forest in Amazonas state January 10, 2015. The Amazon Tall Tower Observatory is a project of Brazil's National Institute of Amazonian Research and Germany's Max Planck Institute and will be equipped with high-tech instruments and an observatory to monitor relationships between the jungle and the atmosphere from next July. According to the institutes, ATTO will gather data on heat, water, carbon gas, winds, cloud formation and weather patterns. (Photo by Bruno Kelly/Reuters)

In Mumbai, the windows of new high-rise apartment blocks, old low-rise residential buildings and shantytown shacks portray the disparity in living conditions and incomes in the Indian city. Rents for a place to live range from more than $2,000 to less than $5 a month. Here: Windows and doors of an old residential building are pictured in central Mumbai October 10, 2014. The cost for buying a residential apartment in Mumbai close to the city centre ranges from 12,000 Indian rupees ($ 200) per square feet to 112,552 Indian rupees ($ 1800) per square feet. (Photo by Danish Siddiqui/Reuters)

A young fan cheers while waiting for the ticker tape parade to celebrate the U.S. women's soccer team World Cup victory, Friday, July 10, 2015, in New York. The World Cup winning U.S. women's football team rolled up New York City's “Canyon of Heroes” on Friday, with a blizzard of confetti swirling overhead in the first ticker-tape parade honouring a women's sports team. (Photo by Adam Hunger/AP Photo)

Padaung ethnic women arrive to listen to the speech of Myanmar opposition leader Aung San Suu Kyi (not in picture), Chairwoman of the National League for Democracy (NLD) party, during Suu Kyi's first official election campaign at Demoso township of Kayah State, eastern Myanmar, 10 September 2015. Suu Kyi is on a three-day visit to Kayah State near the Thai-Myanmar border, as part of her first official election campaign. Myanmar political parties and candidates started their campaigns on 08 September ahead of the upcoming general election, which will be held on 08 November 2015. (Photo by Lynn Bo Bo/EPA)

People look at the Harmony of the Seas cruise ship leaving the STX shipyard of Saint-Nazaire, western France, for a three-day test offshore, on March 10, 2016. With a capacity of 6.296 passengers and 2.384 crew members, the Harmony of the Seas, built by STX France for the Royal Caribbean International, is the world's largest ship cruise. (Photo by Loic Venance/AFP Photo)

People jump off a bridge, which has a height of 30 meters (98ft), in Hortolandia, Brazil, April 10, 2016. According to organizers, 149 people were attempting set a new world record for “rope jumping”, in which people, tied to a safety cord, jump off a bridge. Rope-jumping, an extreme sport, consists in jumping from impressive heights while tied to a nylon rope. Unlike those used in bungee jumping, the rope has no bounce and participants just slow down at the end of the fall. (Photo by Paulo Whitaker/Reuters)