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)

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

Labourers work at the installation site of Liquefied Petroleum Gas (LPG) pipeline on May Day or Labour Day in Chandigarh, India, May 1, 2015. (Photo by Ajay Verma/Reuters)

The car of Dan Wheldon of England driver of the #77 Bowers & Wilkins Sam Schmidt Motorsports Dallara Honda (left) flies in the air during the Las Vegas Indy 300 part of the IZOD IndyCar World Championships presented by Honda on October 16, 2011 at the Las Vegas Motor Speedway in Las Vegas, Nevada. (Photo by Robert Laberge/Getty Images)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)

Actors perform in a scene during the “Dino Safari” show in Tokyo, Japan, 25 April 2018. The Dino Safari show features dinosaurs moving in a realistic way thanks to the Dino-Tronics mechanism that enable the dinosaurs to walk, move their heads and jaws. The event will run from 26 April to 05 May 2018. (Photo by Franck Robichon/EPA/EFE)

A man walks inside the flooded Cochin international airport after the opening of Idamalayar, Cheruthoni and Mullaperiyar dam shutters following heavy rain, on the outskirts of Kochi, India, August 15, 2018. (Photo by Sivaram V/Reuters)

Participants take pictures of themselves as others run past the Tiananmen gate during the Beijing Marathon in Beijing, China, September 17, 2016. (Photo by Damir Sagolj/Reuters)