Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)

Mohammad, a 13-year-old fighter from the “Free Syrian Army”, plays with a cat in Aleppo's Bustan al-Basha district, Syria October 28, 2013. Mohammad joined the Free Syrian Army after his father died during clashes with the Syrian regime. The gun he is using was his father's. (Photo by Molhem Barakat/Reuters)

A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

A person drags a suitcase as a boy clings to it on a square in front of a railway station ahead of the Chinese Lunar New Year in Qingdao, Shandong province, January 28, 2014. About 3.62 billion trips will be made during the 40-day Spring Festival travel rush, which started from January 16, reported Xinhua News Agency citing a government official. (Photo by Reuters/China Daily)

It’s time to start watching for Comet PANSTARRS, one of two comets to get excited about in 2013. Photo: This image provided by NASA shoaws the comet PANSTARRS as seen from Mount Dale, Western Australia on March 5, 2013. According to NASA on March 10, it will make its closest approach to the sun about 28 million miles (45 million kilometers) away. As it continues its nightly trek across the sky, the comet may get lost in the sun's glare but should return and be visible to the naked eye by March 12. (Photo by AP Photo/NASA)

A woman walks past murals adorning the walls of Garibaldi subway station, in Milan, Friday, February 28, 2020. Due to the COVID-19 virus outbreak in northern Italy, the bustling metropolis of Milan has resembled more of a ghost town lately, as workers stayed home and tourism has dwindled there, and other parts of Italy. (Photo by Luca Bruno/AP Photo)

Constanza Mena poses for a photo during a red-nosed walk organized by the Flying Laughter clown group amid the new coronavirus pandemic, in downtown Santiago, Chile, Wednesday, April 28, 2021. The group aims to show that people do not lose the right to play and have fun in the street while pandemic protective measures are in effect. (Photo by Esteban Felix/AP Photo)

Four-year-old Riley Gillet, of Orlando, lights a candle with her family, marking the beginning of the traditional Jewish holiday of Hanukkah, during the Chabad of Greater Orlando's “Chanukah on the Park” celebration in Winter Park, Fla., late Sunday, November 28, 2021. Held at Central Park, the event included the lighting of a giant menorah, live performers, music and dancing. Jews worldwide will celebrate Hanukkah through Dec. 6. (Photo by Joe Burbank/Orlando Sentinel via AP Photo)