A member of the “Castellers Minyons de Terrassa” adjusts her belt before forming a human tower or ÒcastellÓ during the festival of the patron saint of Barcelona “The Virgin of Mercy” at Sant Jaume square in Barcelona, Spain, September 20, 2015. The formation of human towers is a tradition in Catalonia dating back to the 18th century. (Photo by Susana Vera/Reuters)

A man reacts over dead bodies prior to burial in a graveyard after shelling in the rebel held besieged town of Douma, eastern Ghouta in Damascus, Syria, October 24, 2016. (Photo by Bassam Khabieh/Reuters)

HRP-4C, a five-foot humanoid robot developed at Japan's National Institute of Advanced Industrial Science and Technology, sings and dances with performers at the Digital Contents Expo in Tokyo on October 17, 2010. The robot runs entertainment software called Choreonoid, a name formed from the words “choreograph” and “humanoid”. (Yoshikazu Tsuno/AFP)

People stand along Aviation Blvd. as the space shuttle Endeavour lands at LAX in Los Angeles. (Photo by Wally Skalij/Los Angeles Times/MCT)

Kia Vue of St. Paul sports long nails at the Minnesota Hmong New Year celebration Saturday, November 29, 2014, at the Saint Paul RiverCentre in St. Paul, MN. The annual Minnesota Hmong New Year celebration will be held at the Saint Paul RiverCentre November 28–30. Hmong New Year has a deep cultural significance to the Hmong community. It is a celebration of accomplishments during the past year and a time to welcome a new beginning. (Photo by David Joles/Star Tribune)

South Korean rescue members wearing chemical protective suits walk past a monster character (R) during an anti-terror drill as part of a disaster management exercise at the COEX shopping and exhibition center in Seoul on May 20, 2016. South Korea is holding its 2016 Safe Korea anti-disaster exercise this week against terrorist threats and natural disasters. (Photo by Jung Yeon-Je/AFP Photo)

A Houthi follower with fake blood on his clothes lies on the ground to represent a victim as others perform a war dance during a ceremony marking the first anniversary of the Houthi movement's takeover of Yemen's capital Sanaa September 21, 2015. (Photo by Khaled Abdullah/Reuters)

Veterinarian William Guerra Neto (2nd R) and an assistant take measurements of two Amazonian manatees who are being rehabilitated after sustaining injuries from hunting and fishing nets at the Center of Amazonian Manatees at Amana Lake in Maraa, Amazonas state, Brazil, September 21, 2015. (Photo by Bruno Kelly/Reuters)