Dancers perform inside of transparent balls during the Botanical Night at Botanical Garden in Berlin, Germany, 20 July 2018. During the Botanical Night a 16 kilometre long path along the flower beds and several themed gardens are illuminated and guide to many attractions. (Photo by Hayoung Jeon/EPA/EFE)

Video bloggers stream live broadcast of an event to celebrate the fourth birthday of the world's only giant panda triplets, Meng Meng, Shuai Shuai and Ku Ku, at Chimelong Safari Park in Guangzhou, China July 29, 2018. (Photo by Bobby Yip/Reuters)

A girl stretches next to a pram on the embankment of the Moskva river in Moscow on October 18, 2018. The European part of Russia enjoys an unusually warm weather for the season with temperatures reaching up to 22 degrees centigrade. (Photo by Mladen Antonov/AFP Photo)

Girls sits on a bench during summer at the Central Park in New York, United States, 2011. (Photo by An Rong Xu)

Walking figures depicting late US rock and roll legend Elvis Presley appear on a traffic light switching from green to red in Friedberg near Frankfurt, Germany, Thursday, December 6, 2018. Presley served in Friedberg from October 1958 to March 1960 as a soldier in the US Armed Forces. (Photo by Michael Probst/AP Photo)

A person participates in the parade of the “San Jose Carnival” in San Jose, Costa Rica, 27 December 2018. The festival sees people parading through the city's main avenues as part of the San Jose Celebrations that take place at the end of each year. (Photo by Jeffrey Arguedas/EPA/EFE)

A man carries a sheep after it was rescued from mud in Sanliurfa, Turkey on January 9, 2019. Total of 67 sheep and a donkey rescued from mud by gendarmerie forces, firefighters and local people in Sanliurfa's Bozova district. (Photo by Halil Fidan/Anadolu Agency/Getty Images)

Police officers display their AI-powered smart glasses in Luoyang, Henan province, China on April 4, 2018. (Photo by Reuters/China Stringer Network)