“Don't Leave Any Food On Your Plate”. The giraffes at Nairobi's Giraffe Manor are totally at home with humans. They will eat out of your hand, or even off your plate. Photo location: Giraffe Manor, Nairobi, Kenya. (Photo and caption by Gavin Werbeloff/National Geographic Photo Contest)

French army deminers secure a helicopter in a hangar at the Gao airport, on February 9, 2013. Two Malian soldiers and four civilians have already been killed by landmines, and French troops are still fighting off what Paris called “residual jihadists” in reclaimed territory. (Photo by Pascal Guyot/AFP Photo via The Atlantic)

Robot inventor Wu Yulu sits on a rickshaw driven by a robot which he invented in his village in rural Beijing's Tongzhou district, China, 17 November 2016. The 54-year-old Chinese farmer living in rural Beijing's Tongzhou district invented 63 robots in the past 30 years. Wu, who only received primary school education, plans to give up the agricultural work for his robot products. He regularly participates in exhibitions, transfers patent rights and teaches at the university to earn money. (Photo by Wu Hong/EPA)

People out in Aberystwyth on “Booze Black Friday” or “Mad Friday” in Aberystwyth, Wales, UK on December 16, 2016. The “Booze Black Friday” is the last working Friday before Christmas when workers celebrate with their colleagues. Alcohol sales in pubs, clubs and off-licences rise dramatically on this day. (Photo by Keith Morris/Alamy Live News)

United States' Inika McPherson prepares an attempt during the women' s high jump final during the World Athletics Championships in London Saturday, August 12, 2017. (Photo by Kai Pfaffenbach/Reuters)

A walrus kisses a visitor during a sea animal show at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Monday, September 11, 2017. (Photo by Shizuo Kambayashi/AP Photo)

David Cassidy (1950-2017) and Kay Lenz at their wedding at The Little Church Of The West in Las Vegas, Nevada, 1977. (Photos by Brad Elterman/FilmMagic)

Students of the Krasnoyarsk choreographic college Anastasia Shevtsova (R) and Yulia Lyakhovykh do leg-splits as they study for an exam and a performance by the graduates at the State Theatre of Opera and Ballet, at the college's campus in the Siberian city of Krasnoyarsk, Russia, May 4, 2017. (Photo by Ilya Naymushin/Reuters)