People cross Flagstaff Hill as the snow starts to fall, in Schenley Park, on their way to the Carnegie Mellon University campus, Tuesday, March 20, 2018, in the Oakland section of Pittsburgh. Yet another powerful storm bore down on the Northeast on Tuesday, with wind-whipped snow falling in parts of Pennsylvania and New Jersey as people grumbled and complained about a first day of spring that looked an awful lot like the last weeks of winter. (Photo by Darrell Sapp/Pittsburgh Post-Gazette via AP Photo)

A Bedouin rifleman hides behind his camel while he carefully takes aim in the Sahara desert. (Photo by Three Lions/Getty Images). Circa 1955

A humanoid robot named “Yangyang” shows a facial expression during its demonstration at the Global Mobile Internet Conference (GMIC) 2015 in Beijing, China, April 29, 20155. The android was produced jointly by China's Shanghai Yangyang Intellegent Robot Science Service center and Japanese professor Hiroshi Ishiguro, with the aim of popularising robotics among the young. (Photo by Kim Kyung-Hoon/Reuters)

A model takes part in an exhibition, a part of Lingerie Show-Forum 2016 international lingerie, swimwear, homewear and hosiery trade show in Moscow, Russia, February 26, 2016. (Photo by Sergei Karpukhin/Reuters)

People follow king penguins exploring their outdoor pen, during a so-called “penguin parade”, when the animals walk outside their enclosure and the visitors can walk behind them, at Zurich's Zoo in Zurich, Switzerland January 28, 2017. (Photo by Arnd Wiegmann/Reuters)

A visitor looks at a sculpture entitled “Couple Under an Umbrella, 2013” by artist Ron Mueck during the press day for his exhibition at the Fondation Cartier pour l'art contemporain in Paris April 15, 2013. (Photo by Charles Platiau/Reuters)

Australian actress Joy Smithers poses beside a poster featuring Australian cricketer Brett Lee during the official launch of the AceStar underwear range at Pink Salt on August 19, 2008 in Sydney, Australia. (Photo by Mike Flokis/Getty Images)

Indian labourers carry clay bricks to a brick kiln in Farakka, in the Indian state of West Bengal, on April 3, 2019. (Photo by Xavier Galiana/AFP Photo)