This picture taken on June 1, 2019 shows Alex Gao trying to balance a book on his head during an etiquette and manners class in central Shanghai. Against a soundtrack of classical music, children learn social skills, dining manners and deportment in the class, which costs $390 for four hours of practical instruction per student. (Photo by Hector Retamal/AFP Photo)

Britain's Prime Minister Boris Johnson gestures during a visit to Darnford Farm in Banchory near Aberdeen in Scotland on September 6, 2019. Prime Minister Boris Johnson heads to Scotland on Friday in campaign mode despite failing to call an early election after MPs this week thwarted his hardline Brexit strategy. (Photo by Andrew Milligan/Pool via AFP Photo)

Children try to push an injured and weak dolphin back into the water after it washed ashore during bad weather and high tide on a beach in Cilacap, Central Java, Indonesia August 12, 2016 in this photo taken by Antara Foto. (Photo by Idhad Zakaria/Reuters/Antara Foto)

British prime minister Winston Churchill (1874–1965) stops to pet a cat at Liverpool Street Station, 24th May 1952. (Photo by Keystone/Hulton Archive/Getty Images)

This greedy piglet was isolated from the rest of its litter by the farmer who named it Hitler after it tried to grab all the food at feeding time. (Photo by R J Lewis/Getty Images). 1942

Battle-weary American troops withdraw from Yong San in Korea. (Photo by Keystone/Getty Images). 1950

A leopard seal feeds Paul Nicklen a penguin. (Photo by Paul Nicklen/National Geographic). Antarctic Peninsula, 2011

An airplane crosses a nearly full-moon on its way to Los Angeles International Airport near Whittier, Calif., Thursday, December 24, 2015. Not since 1977 has a full moon dawned in the skies on Christmas. (Photo by Nick Ut/AP Photo)