A passenger waits after his train arrived in Nouadhibou, Mauritania’s second largest city and the main export port for the country’s iron ore industry, on June 25, 2014. The mining company’s employees proudly call their firm the lung of their nation's economy and the train that ferries the ore to the coast stretches some two kilometres, making it one of the world's longest. SNIM mines black iron ore in the northern town of Zouerate, a remote desert location which nevertheless attracts people from all over the country looking for work. (Photo by Joe Penney/Reuters)

Vivian Odhiambo, 24, frys samosas in the trading centre of Kogelo, west of Kenya's capital Nairobi, July 14, 2015. Odhiambo said, “Obama is our hero and we wait to welcome him back home again. We in Kogelo have witnessed general growth and we are proud of being associated with the Obamas”, she added. As U.S. President Barack Obama visits Kenya, a personal connection to his father's birthplace of Kogelo dominates a trip that Kenyans view as a native son returning home. Residents from a herdsman to a housewife share their views on what Obama has achieved and what they would like to see next. (Photo by Thomas Mukoya/Reuters)

Colombia' s Caterine Ibarguen competes in the women' s long jump during the 2018 IAAF Birmingham Diamond League athletics meeting at Alexander Stadium in Birmingham on August 18, 2018. (Photo by Peter Cziborra/Action Images via Reuters)

U.S. first lady Melania Trump steps out of her motorcade vehicle as she departs Washington for a tour of several African countries from Joint Base Andrews, Maryland, U.S., October 1, 2018. (Photo by Carlo Allegri/Reuters)

A woman poses after she got an image of a lion tattooed on her back as part of awareness campaign to save Asiatic lions and in preparations for the upcoming Navratri festival in Ahmedabad, India, October 5, 2018. (Photo by Amit Dave/Reuters)

An Afghan woman walks with a child in the old city of Herat province, Afghanistan on October 15, 2018. (Photo by Mohammad Ismail/Reuters)

Woman dons a mask a she prepares to dance in the streets during the feast of La Diablada, in Pillaro, Ecuador, Friday, January 4, 2019. The town of Pillaro kicks off the feast of the La Diablada with neighborhoods competing to bring as many people dressed as different characters. (Photo by Dolores Ochoa/AP Photo)

PETA (People for the Ethical Treatment of Animals) activists protest in front of the venue during the Berlin Fashion Week Autumn/Winter 2019/20 in Berlin, Germany, January 15, 2019. (Photo by Fabrizio Bensch/Reuters)