Santa Claus reacts as (L) Tami McEleney and (R) Patrice Conner whisper in his ear at the King of Prussia Mall, United States' largest retail shopping space, in King of Prussia, Pennsylvania, U.S., December 8, 2018. (Photo by Mark Makela/Reuters)

Vegetables, wood and charcoal are loaded onto the roof of a battered Peugeot on November 7, 2018 in Matadi, Democratic Republic of the Congo. From the port of Matadi to the capital Kinshasa, a 350 km road crosses the south-west of the Democratic Republic of Congo. (Photo by Junior D. Kannah/AFP Photo)

An Okinawan woman in a kimono checks her phone before attending a ceremony on Coming of Age Day on January 13, 2019 in Okinawa City, Japan. Coming of Age Day is a Japanese holiday held every January to celebrate people who have reached 20 – the official age of adulthood in Japan. Despite being a solemn affair in some parts of Japan, Okinawans have become known for their flamboyant and occasionally boisterous celebrations. (Photo by Carl Court/Getty Images)

In this photo taken on Saturday, January 26, 2019 photo, rescued flamingo chicks have access to water at a centre after being rescued from a dried out dam in Kimberley, South Africa. A special airlift for thousands of baby flamingos is under way in South Africa as drought has put their breeding ground in peril. A reservoir that hosts one of southern Africa's largest flamingo populations is drying up. (Photo by AP Photo/Stringer)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

Russian soldiers from 34th motorized infantry mountain brigade, 58th Army, prepare to evacuate a fellow soldier acting as an injured person during a drill at the Darial range outside Russia's city of Vladikavkaz, July 28, 2010. (Photo by Kazbek Basayev/Reuters)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)