A boy takes a picture of a car crash in Shenzhen, Guangdong province, August 4, 2014. Two passengers were sent to hospital but no death was reported as a result of the accident, according to local media. (Photo by Reuters/Stringer)

A participant of the sled dogs race in action with the dogs in Stroehen (Lower Saxony), Germany, 18 October 2015. It is the first round of the North German Championship. (Photo by Peter Steffen/EPA)

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)

An urban fox walks alongside the Mall in central London, Britain, November 29, 2016. (Photo by Toby Melville/Reuters)

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 student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

Migrants storm into a train at the Keleti train station in Budapest, Hungary, September 3, 2015 as Hungarian police withdrew from the gates after two days of blocking their entry. (Photo by Laszlo Balogh/Reuters)

A man runs after he tried to put himself on fire during a protest at a makeshift camp at the Greek-Macedonian border near the village of Idomeni on March 22, 2016. Greece will not be able to start sending refugees back to Turkey from March 20, 2016, the government said, as the country struggles to implement a key deal aimed at easing Europe's migrant crisis. The numbers are daunting: officials said as of Saturday there were 47,500 migrants in Greece, including 8,200 on the islands and 10,500 massed at the Idomeni camp on the Macedonian border. (Photo by Andrej Isakovic/AFP Photo)