Masked Palestinian demonstrators hide behind a metal plate during clashes with Israeli soldiers on March 12, 2018 in the West Bank town of Birzeit, near Ramallah, following a protest by students of the Birzeit University against the arrest of the the head of Palestinian student council by an Israeli undercover commando. (Photo by Abbas Momani/AFP Photo)

Couples take part in a Valentine's Day attempt to break the record for the world's largest simultaneous gay kiss on February 14, 2004 in Rome, Italy. (Photo by Franco Origlia/Getty Images)

Fireworks explode over a floating Christmas tree in Lagoa Lake in Rio de Janeiro. (Photo by Victor R. Caivano/Associated Press)

Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

In this October 7, 2018 photo waitress dance in the Hofbraeu tent after the closing of the Oktoberfest beer festival in Munich, southern Germany, which ran from September 22 through October 7, 2018. (Photo by Felix Hoerhager/AP Photo)

Graduates dance as they take part in a “Last school bell” ceremony at a school in Minsk, Belarus on May 30, 2018. (Photo by Vasily Fedosenko/Reuters)

Two students in Birmingham, United Kingdom dressed as policewomen enjoy a takeaway on October 31, 2018. Halloween party-goers enjoyed one hell of a night for the annual fright-fest. (Photo by Caters News Agency)

A youth skates next to a road in Palembang, South Sumatra, Indonesia on August 15, 2018. (Photo by Edgar Su/Reuters)