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)

In this photo taken Thursday, August 13, 2015, a man walks past the charred remains of new cars at a parking lot near the site of an explosion at a warehouse in northeastern China's Tianjin municipality. Rescuers have pulled a survivor from an industrial zone about 32 hours after it was devastated by huge blasts in China's Tianjin port. Meanwhile, authorities are moving gingerly forward in dealing with a fire still smoldering amid potentially dangerous chemicals. (Photo by Ng Han Guan/AP Photo)

A museum employee views “Details of Renaissance Paintings (Sandro Botticelli, Birth of Venus, 1482)” by Andy Warhol at the Victoria and Albert museum in London, Britain, March 2, 2016. The piece forms part of “Botticelli Reimagined”, an exhibition exploring the ways artists have responded to the artistic legacy of the fifteenth century artist Sandro Botticelli, and including over fifty artworks by Botticelli himself. (Photo by Toby Melville/Reuters)

Participants in traditional dress ride on horseback as they enjoy the atmosphere at the Feria de Abril (April's Fair) on April 12, 2016 in Seville, Spain. The Feria de Abril has a history that dates back to 1857 and takes place a fortnight after Easter each year. The origin of the fair was a cattle market but the event quickly turned its goal from commerce to having fun. More than 1 million local and international participants are expected to attend the Feria de Abril. (Photo by David Ramos/Getty Images)

Tourists visit the Corral Canyon Cave in Malibu, Calif., Friday, May, 6, 2016. The cave, better known by the misleading moniker “Jim Morrison Cave” is now closed to the public until further notice. Large crowds have shown up on a daily basis to see the often vandalized cave and in some cases add to the vandalism with graffiti of their own. (Photo by Damian Dovarganes/AP Photo)

In this June 1, 2016 photo, Maria Arias stands near her kitchen as she puts on earrings while getting ready for school in Caracas, Venezuela. So many students have fainted from hunger at Maria's school that administrators told parents to keep their children home until they could find more food. (Photo by Ariana Cubillos/AP Photo)

A crocodile at a zoo in the southern Taiwan city of Kaohsiung holds the forearm of a zoo veterinarian in its teeth, April 2007. Surgeons in Taiwan have reattached a vet's arm, after it was bitten off by a crocodile as he tried to give it an anaesthetic injection. His attacker is one of a pair of Nile crocodiles kept at Shoushan zoo. Nile crocodiles are known to be man-eaters, but are also listed as an endangered species. (Photo by Frank Lin/Reuters)

Rebel fighters fire towards positions of regime forces in Ramussa on the southwestern edges of Syria's northern city of Aleppo on August 6, 2016. Syrian rebels said they have broken a three-week government siege of second city Aleppo, turning the tables on Russian-backed regime forces who are now on the defensive. (Photo by Fadi Al-Halabi/AFP Photo)