People sit on the top of a truck heavily piled with corn-stalks plies as they head for Mogadishu from Afgooye on October 19, 2016. At least four police officers were killed on October 18 when a suicide bomb attacker rammed an explosives-packed car into a police station before fighters from the Al-Qaeda-linked Shabaab group subsequently stormed the area killing at least 10 people, including soldiers and civilians. (Photo by Mohamed Abdiwahab/AFP Photo)

People dance Tuesday, April 28, 2015, in Baltimore. Maryland's governor vowed there would be no repeat of the looting, arson and vandalism that erupted Monday in some of the city's poorest neighborhoods. (Photo by Matt Rourke/AP Photo)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)

The Hubble Space Telescope is shown following its release from the space shuttle Discovery Wednesday, February 19, 1997. The Hubble Space Telescope, one of NASA'S crowning glories, marks its 25th anniversary on Friday, April 24, 2015. With more than 1 million observations, including those of the farthest and oldest galaxies ever beholden by humanity, no man-made satellite has touched as many minds or hearts as Hubble. (Photo by AP Photo/NASA)

Girls accompany grooms as they sit separate from the brides during a mass wedding for 150 couples in Beit Lahiya town in the northern Gaza Strip July 20, 2015. The wedding was funded by al-Basheer Society for Relief and Development. (Photo by Suhaib Salem/Reuters)

A little girl takes a picture of a lion in the zoo in Frankfurt, Germany, Tuesday, September 13, 2016. (Photo by Michael Probst/AP Photo)

A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)

Russia's synchronised swimming duet Aleksandr Maltsev (L) and Darina Valitova compete in the Mixed Duet Technical preliminary during the synchronised swimming competition at the 2015 FINA World Championships in Kazan on July 25, 2015. (Photo by Christophe Simon/AFP Photo)