A man sleeps between tombstones in front of his single-room home on a hot night in the Cairo Necropolis, Egypt, October 13, 2015. In the sprawling Cairo Necropolis, known as the City of the Dead, life and death are side by side. Amid a housing crisis in Egypt, and with the population of greater Cairo estimated at about 20 million, people count themselves lucky to have a place to call home in the graveyards that date back hundreds of years. (Photo by Asmaa Waguih/Reuters)

A humanoid robot named “Robi” sits during a promotional event for the launch of a weekly Robi Magazine in Tokyo, Japan, 20 January 2015. Created by roboticist Tomotaka Takahashi, the 34-centimeter tall humanoid robot can recognize and respond to more than 200 words and phrases, walk and dance. Parts of the robot will be put on sale in a weekly magazine to be fully assembled with 70 issues. (Photo by Franck Robichon/EPA)

A beachgoer walks past a buoy that washed ashore after Hurricane Isabel made landfall September 19, 2003 in Virginia Beach, Virginia. (Photo by Joe Raedle/Getty Images)

A soldier walks on the bank of the river in central Pyongyang, North Korea on April 16, 2017. (Photo by Damir Sagolj/Reuters)

The Royal Castle is seen a veil of heavy winter smog in Budapest, Hungary on January 30, 2017. (Photo by Laszlo Balogh/Reuters)

Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

A crocodile at a zoo in the southern Taiwan city of Kaohsiung holds the forearm of a zoo veterinarian in its teeth, April 2007. Surgeons in Taiwan have reattached a vet's arm, after it was bitten off by a crocodile as he tried to give it an anaesthetic injection. His attacker is one of a pair of Nile crocodiles kept at Shoushan zoo. Nile crocodiles are known to be man-eaters, but are also listed as an endangered species. (Photo by Frank Lin/Reuters)

A participant in costume and make-up poses for a photo during a Halloween parade at Walibi park in Wavre, Belgium, October 31, 2018. (Photo by Yves Herman/Reuters)