Tourists pose with pigeons in the flooded St. Mark's Square in Venice, on November 7, 2014. The high water, a combination of high tides and a strong Scirocco wind in the Adriatic Sea, stood at 110 centimeters early on November 7. The city has for years been wrestling with the problems posed by the threat of rising sea levels. (Photo by Olivier Morin/AFP Photo)

People watch as workers inflate a near-10 metre high giant spider by Singaporean artist Jackson Tan in Singapore's Marina Bay financial district on February 6, 2017. The spider is one of several inflatable creatures that will form the Art-Zoo, a section created by Singaporean artist Jackson Tan for the iLight Marina Bay annual light-art festival in the city-state. (Photo by Roslan Rahman/AFP Photo)

Two traditional folk dancers performing in Teheran, Iran. (Photo by Keystone Features/Getty Images). 25th January 1961

Reuters Photographer Carlos Barria photographed a person born in each year China's one child policy has been in existence; from a man born in 1979, to a baby born in 2014, and asked them if they would have like to have siblings. Here: Lv Mengmeng, who was born in 1995, poses for a photograph in Shanghai August 22, 2014. When asked if she would like siblings, Mengmeng said: “Maybe brothers, because I think they could protect me”. (Photo by Carlos Barria/Reuters)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

Two men fight in San Jose, Costa Rica, during the Women's Day on March 8, 2014. (Photo by Jeffrey Arguedas/EFE/SIPA Press)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

A woman is detained by security forces after looting broke out during an ongoing blackout in Caracas, Venezuela, March 10, 2019. (Photo by Ivan Alvarado/Reuters)