In this Saturday, April 8, 2017 photo, a keeper walks camels to the Al Marmoom Camel Racetrack, in al-Lisaili about 40 km (25 miles) southeast of Dubai, United Arab Emirates. Camel racing is a big-money sport and fast thoroughbreds can fetch well over a million dollars. As rising temperatures across Gulf Arab countries signal the end of the winter camel racing season, Dubai is wrapping up its races with the annual Al Marmoom Heritage Festival that has drawn thousands of camels from across the oil-rich Gulf. (Photo by Kamran Jebreili/AP Photo)

A doll in a children's gas mask is seen amongst beds at a kindergarten in the abandoned city of Pripyat near the Chernobyl nuclear power plant in Ukraine on March 28, 2016. Deadly radiation still spews from Chernobyl 30 years after the worst nuclear meltdown in history, as a newly built giant arch is pulled into place to cover the stricken reactor for the next century. (Photo by Gleb Garanich/Reuters)

Sgt. William Olas Bee, a U.S. Marine from the 24th Marine Expeditionary Unit, has a close call after Taliban fighters opened fire near Garmsir in Helmand Province of Afghanistan, May 18, 2008. (Photo by Goran Tomasevic/Reuters)

“Dubai is sometimes called the “City of Gold” because of its stunning growth from a sleepy Gulf port to a world-famous business crossroads in the space of a single generation. Its nickname has a literal meaning for traders in the precious metal. The city is building itself up as a center for the gold trade, between sources in Africa and consumers in the rising economies of China and India”. – Kamran Jebreili via Associated Press

Photo: A gold press operator collects 10 gram gold blanks to press them with the logo of the Emirates Gold company in Dubai, United Arab Emirates. Gold prices remained relatively steady in 2012, close to $1,700 an ounce. (Photo by Kamran Jebreili/AP Photo)

The tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away from Earth in the southern constellation Carina. (Photo by Reuters/NASA)

Brain-on-a-chip. Dazzling in green and magenta this image shows the nerve fibres (in green) produced by neural stem cells (in magenta) as they grow on a synthetic gel. Captured by a technique known as confocal microscopy, the image is part of research shedding light on how tinkering with the environment can affect the way in which nerve fibres grow. (Photo by Collin Edington and Iris Lee/Massachusetts Institute of Technology/Wellcome Images)

An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

The Lamb National takes place for the racegoers at Ascot Racecourse on April 2, 2017 in Ascot, England. (Photo by Alan Crowhurst/Getty Images)