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)

Meghan Puhr participates in a virtual realty presentation during an Intel news conference before CES International, Wednesday, January 4, 2017, in Las Vegas. (Photo by John Locher/AP Photo)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

A 70-metre-long Noah's Ark replica constructed of steel and American cedar on March 31, 2005 in Schagen, Netherlands. (Photo by Michel Porro/Getty Images)

“Festive preparation”. Baghnapara, Bardhaman, West Bengal, India. Two girls prepare for the Gajan festival. They will perform a play based on Indian mythology. (Photo by Krishnasis Ghosh)

Women take part in a march in Santiago on October 19, 2016, to protest against violence against women and in solidarity for the brutal killing of a 16- year- old girl in Mar del Plata, Argentina last week The killing, in which the high school student was allegedly raped and impaled on a spike by drug dealers, is just the latest incident of horrific gender violence in Argentina, which has seen more than a year of mass marches to protest brutality against women. (Photo by Claudio Reyes/AFP Photo)

These stunning photographs really do show a land of fire and ice! The frozen landscape of the Olkhon Islands, Russia, appears to be ablaze in some of these pictures as the icy sheets of the glaciers reflect the early morning suns rays. (Photo by Vladimir Ryabkov/Caters News Agency)

Revellers take part in the annual Gay Pride parade along Paulista Avenue in Sao Paulo, Brazil, May 29, 2016. (Photo by Nacho Doce/Reuters)