A Macedonian police officer hits a stranded migrant attempting to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)

Members of Japan's idol group “Virtual Currency Girls” wearing cryptocurrency-themed masks perform in their debut stage in Tokyo, Japan, January 12, 2018. Japanese female idols have teamed up to form the ‘Virtual Currency Girls’ group to promote the knowledge of cryptocurrencies through entertainment. Each of its 8 members represents a cryptocurrency: bitcoin cash, bitcoin, ether, neo, nem, ripple, mona, and cardano. (Photo by Kim Kyung-Hoon/Reuters)

Happiness on a Rainy Day by Fardin Oyan, Bangladesh. Winner of the young environmental photographer of the year. Many children in Bangladesh love to bathe and play in the rain. The country, which is flat and occupied by the huge Ganges-Brahmaputra Delta, is exposed to floods, especially during monsoon season. (Photo by Fardin Oyan/2018 Ciwem environmental photographer of the year 2018)

Visitors are seen inside a newly opened bookstore in Chongqing, China on January 29, 2019. Covering an area of 1,400 square meters, the Zhongshuge Bookstore in Chongqing attracts readers with its creative decor. (Photo by Reuters/China Stringer Network)

A boy doing chin-ups as he takes entrance exams at the Moscow Suvorov Military School in Moscow, Russia on July 11, 2019. (Photo by Sergei Karpukhin/Russian News Agency TASS via Getty Images)

Undated handout issued by Take A View of Sunrise at Winnats Pass, Derbyshire, England which won the Visit Britian “You're invited” Award for the best image from an overseas entrant category in this year's Landscape Photographer of the Year Awards. (Photo by Sven Mueller/PA Wire)

The Perseid Meteor Shower seen over The Scorhill Stone Circle in Dartmoor, Devon on August 2, 2016. (Photo by John Baker/SWNS.com)

Train attendants carry their luggage as they walk through a flooded street in Fuzhou in southeastern China's Fujian Province Wednesday, September 28, 2016. The massive typhoon made landfall in eastern China Wednesday, a day after carrying strong winds over Taiwan that felled trees and scattered debris, killing several people and injuring hundreds. (Photo by Chinatopix via AP Photo)