In this photo taken Saturday, January 24, 2015, a child makes a face while having her photo taken with the snow covered slopes of the Nanshan ski resort behind her in Beijing. As Beijing makes a final push in its bid for the 2022 Winter Olympics, Chinese President Xi Jinping says winning the bid will encourage over 300 million Chinese to take up winter sports by 2022, according to state-run Xinhua News agency. (Photo by Ng Han Guan/AP Photo)

A masked reveller parades through the streets on the first day of the carnival season in Lucerne, Switzerland, 12 February 2015. In the background the well known Kappellbruecke bridge. (Photo by Alexandra Wey/EPA)

Paul, 9, dumps a bucket of water over his head at a fountain near government buildings during hot weather on July 1, 2015 in Berlin, Germany. Temperatures across northern Europe are rising and in Germany a high of 36 degrees is forecast for the weekend. (Photo by Sean Gallup/Getty Images)

College students take shelter at a traffic point as a man paddles his rickshaw through a flooded road during heavy rain in Guwahati, India, June 13, 2017. (Photo by Anuwar Hazarika/Reuters)

Hillary Clinton waves to a selfie-taking crowd at a recent campaign event in Orlando, Florida on September 26, 2016. (Photo by Barbara Kinney/Hillary for America)

In this photo taken on Thursday, September 6, 2018, a women releases an arrow during an archery competition during the Third Nomad Games, in Cholpon-Ata, 250 kilometers (156 miles) of Bishkek, Kyrgyzstan. The Central Asian nation of Kyrgyzstan held its biennial Nomad Games to promote and celebrate traditional sports of nomadic people. The week-long competition, which is held in a gorge near the picturesque Lake Issyk-Kul, feature traditional sports of nomad peoples such as horseback wrestling and goat polo. (Photo by Vladimir Voronin/AP Photo)

An American soldier walks ahead of an MKIV (Mark IV) British-made tank, circa 1918. (Photo by Hulton Archive/Getty Images)