A woman carries earthen pots to fill them with drinking water on a hot summer day, on the outskirts of Ajmer, Rajasthan, India April 25, 2017. (Photo by Himanshu Sharma/Reuters)

A man sits on top of a car as he is stranded on a flooded street in Tianjin, China, July 20, 2016. (Photo by Reuters/Stringer)

This photo provided by Netflix/naturepl.com and WWF-International shows an African Elephant (Loxodonta africana) in front of double rainbow, in Masai Mara, Kenya, included in the Netflix natural history series, “Our Planet”, in collaboration with Silverback Films and WWF. The eight-part series debuts in 2019. (Photo by Andy Rouse/Naturepl/WWF-International/Netflix via AP Photo)

A couple hugs while standing near a Christmas tree made out of plastic bins and plastic hampers outside the Museum of History in Monterrey, Mexico, December 4, 2015. The humble Christmas tree has a rich history, from evergreen trees used to symbolise eternal life in Ancient Egypt to tree worship among pagan Europeans. The modern version has its origins in Germany, where the song “O Tannenbaum” is still a festive favourite. Today the traditional tree with lights and decorations appears in cities including Washington, Moscow and Beirut. Alternative constructions range from recycled rubbish in Mexico City to old window frames in Rakvere, Estonia. Whatever the shape or size, the message is the same: Merry Christmas. (Photo by Neil Hall/Reuters)

North Korean youngsters sing and play accordions to entertain foreign visitors including United Nations Secretary General Kurt Waldheim, who visited Pyongyang, May 4, 1979. Visitors report music education in North Korea begins at an early age and is taken seriously by children and adults. (Photo by Peter Arnett/AP Photo)

A woman walks on the stairs decorated with an image of two hands shaking to form the shape of the Korean Peninsula to support the upcoming inter- Korean summit, in downtown Seoul on September 17, 2018. South Korean President Moon Jae- in will fly to the North Korean capital on September 18, for his third summit with the North' s leader Kim Jong Un as a rapid diplomatic thaw takes hold on the peninsula despite stalled progress in denuclearisation talks between Pyongyang and Washington. (Photo by Jung Yeon-je/AFP Photo)

A participant races in the Brompton World Championship in Bern, Switzerland October 21, 2018. (Photo by Stefan Wermuth/Reuters)

A man walks his dog as the sun sets in a park in Frankfurt, Germany, Monday, September 18, 2017. Cool damp weather is set to continue in this part of Germany for the next few days with temperatures in the mid teens Celsius. (Photo by Michael Probst/AP Photo)