A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

Eight-year-old handicapped Chinese girl Qian Hongyan crawls with two home-made props and part of a basketball at Zhuangxia Village on January 5, 2005 in Luliang County of Qujing City, Yunnan Province, China. The girl who lost both of her legs in a traffic accident in 2000 at the age of three, struggles to live her life with a basketball as an underprop, “walking” between school and home by herself. The girl's story is widely reported in the country, and experts from China Rehabilitation Research Center has come to Qian's home to help her for rehabilitative treatment early 2005. (Photo by China Photos/Getty Images)

The Queen Elizabeth Tower (Big Ben) is reflected in a puddle as a cyclist rides by in London, on 27 June 2016. Britain began preparations to leave the European Union on Monday but said it would not be rushed into a quick exit, as markets plunged in the wake of a seismic referendum despite attempts to calm jitters. (Photo by Leon Neal/AFP Photo)

An artist's impression of a growing supermassive black hole located in the early Universe is seen in this NASA handout illustration released on June 15, 2011. Using the deepest X-ray image ever taken, astronomers found the first direct evidence that massive black holes were common in the early universe. This discovery from NASA's Chandra X-Ray Observatory shows that very young black holes grew more aggressively than previously thought, in tandem with the growth of their host galaxies. (Photo by Reuters/NASA/Chandra X-Ray Observatory/A.Hobart)

Boeing 747-400 of KLM in approach for the “Princess Juliana” airport, Netherlands Antilles Sint Maarten on July 2, 2002. (Photo by LUPOO/Ullstein Bild via Getty Images)

It might have been foggy in the Willamette Valley, but Cerridwen Martin was able to revel in a view of the top of the clouds from the summit of Spencer Butte in Eugene, Ore., on Tuesday, December 16, 2014. Martin was joined by Joe Martinson, right, for the 1.1 mile trek. Fog shrouded much of the city for most of the day. (Photo by Andy Nelson/AP Photo/The Register-Guard)

A boy tumbles as he plays soccer on the streets of the Khayelitsha township in Cape Town, December 3, 2009. (Photo by Kai Pfaffenbach/Reuters)