A boy pushes a donkey cart loaded with bundles of cotton blooms that were collected by women cotton pickers in Meeran Pur village, north of Karachi September 25, 2014. Women make up the bulk of Pakistan's half a million cotton producers, but labour rights activists say they are often exploited by overseers, who often withhold their wages and may subject some of them to sexual harassment. (Photo by Akhtar Soomro/Reuters)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

A vendor pushes an improvised cart with a woman and merchandise along a rarely used rail track in Bangkok, Thailand, Thursday, June 25, 2020. Daily life in the capital slowly returns to normal as the Thai government eases many restrictions imposed weeks ago to combat the spread of COVID-19. Though emergency regulations require the use of face masks in public, some residents have become apathetic as Thailand has record zero local transmission for over three weeks. (Photo by Gemunu Amarasinghe/AP Photo)

A Fulani Pastoralist carries two baby sheep on her donkey cart as her family move on northwards in Barkedji, Senegal on July 21, 2020. Thousands of Pastoralist families will start the movement north in the next weeks. With the first rains comes fresh grass and water for the Fulani herders' livestock, it also marks the point where most of the Pastoralist will move northwards until the dry season. (Photo by John Wessels/AFP Photo)

Tube passengers take a selfie next to a London underground roundel designed for the launching of the Night Tubes on display at Oxford Circus underground station in London, Britain, 19 August 2016. The long delayed Night Tubes service launched on 19 August. The 24-hour service will operate on Fridays and Saturdays. (Photo by Hannah Mckay/EPA)

A group of people are seen on a Victoria line train in London, England during the first night of the Night Tube service on August 19 2016. The Central line and Victoria line are the first to operate a Night service with further lines expected to be running by the end of the year. (Photo by SWNS.com)

Passengers pose for a selfie as they wait for the Night Tube train service at Oxford Circus on the London underground system in London, Britain August 20, 2016. The London Underground is starting its first-ever overnight service, a move city leaders hope will make the British capital a truly 24-hour city and bolster the local economy. (Photo by Paul Hackett/Reuters)