Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP Photo)

SoftBank's human-like robot named “Pepper” poses for pictures in its role as a PR manager of Tottori prefecture at the prefecture speciality store in Tokyo, Japan, July 1, 2015. Pepper will work at the store until July 2, as the first workplace venue for its temporary staffing service. (Photo by Yuya Shino/Reuters)

Star Wars enthusiasts wear costumes resembling what they say are three “Chew's Angels” during the 2015 Comic-Con International Convention in San Diego, California July 10, 2015. (Photo by Mario Anzuoni/Reuters)

Bottlenose dolphins swim over visitors in water tank at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Tuesday, July 21, 2015. Temperatures in Tokyo's metropolitan area neared around 96 degree Fahrenheit, or 35 degree Celsius, on Tuesday. (Photo by Shuji Kajiyama/AP Photo)

A traffic police woman whistles at a pedestrian, Monday, July 27, 2015, in Pyongyang, North Korea where its citizens are having a one-day national holiday to celebrate the country's 62nd anniversary of the armistice that ended the Korean War. (Photo by Wong Maye-E/AP Photo)

An Indian artist performs with fire during a procession as part of “Bonalu” festival in Hyderabad, India, Monday, Aug.10, 2015. Bonalu is a month long Hindu folk festival of India's Telangana region dedicated to Kali, the Hindu goddess of destruction. (Photo by Mahesh Kumar A./AP Photo)

A passenger plane comes into land over a field containing horses at Heathrow Airport on August 11, 2014 in London, England. Heathrow is the busiest airport in the United Kingdom and the third busiest in the world. The airport's operator BAA wants to build a third runway to cope with increased demand. (Photo by Peter Macdiarmid/Getty Images)

Yana Shcherban of Russia looks at the ball after failing to receive it during their FIVB Women's Volleyball World Grand Prix 2014 final round against Japan in Tokyo August 20, 2014. (Photo by Yuya Shino/Reuters)