Yang Juan, an employee at Goopal Group, takes a nap in her seat after lunch, in Beijing, China, April 21, 2016. Office workers sleeping on the job is a common sight in China, where a surplus of cheap labour can lead to downtime at work. But in China's technology sector, where business is growing faster than many start-up firms can hire new staff, workers burn the midnight oil to meet deadlines and compete with their rivals. Some companies provide sleeping areas and beds for workers to rest during late nights. (Photo by Jason Lee/Reuters)

Carlos Cure holds packets of corn flour made in Colombia as he poses for a picture at a stall that sells food and staple items at a market in La Fria, Venezuela, June 2, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

Heavy artillery on parade during a review of the Moscow Garrison troops during the May Day celebrations in Red Square, passing posters of Lenin and Stalin. (Photo by N. Sitnikov/Hulton Archive/Getty Images). 1st May 1947

Alluvial Fan, China. A vast alluvial fan blossoms across the desolate landscape between the Kunlun and Altun mountain ranges that form the southern border of the Taklimakan Desert in China’s XinJiang Province. Image taken by the ASTER instrument on NASA’s Terra satellite on May 2nd, 2002. (Photo by NASA/GSFC/USGS EROS Data Center)

Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)

Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

South Sudanese wrestlers take part in a wrestling match for peace in Juba on April 19, 2016. The last wrestling match for peace was held in Juba the day before civil war broke out in December 2013. (Photo by Carl de Souza/AFP Photo)

Models display a creation by K-Lynn Lingerie during a fashion show in the Lebanese capital Beirut on April 24, 2016. (Photo by Anwar Amro/AFP Photo)