Riot police officers in position to crack down on demonstrators during a protest against Venezuelan President Nicolas Maduro, in Caracas on April 20, 2017. Venezuelan riot police fired tear gas Thursday at groups of protesters seeking to oust President Nicolas Maduro, who have vowed new mass marches after a day of deadly unrest. Police in western Caracas broke up scores of opposition protesters trying to join a larger march, though there was no immediate repeat of Wednesday's violent clashes, which left three people dead. (Photo by Juan Barreto/AFP Photo)

A reveler attends the “Volta, Alice” celebrations before Rio Carnival, in Rio de Janeiro, Brazil, 17 February 2019. The Carnival in Rio de Janeiro runs from 02 to 09 March 2019. (Photo by António Lacerda/EPA/EFE)

The Turkish merchant ship Efe Murat is driven aground in strong winds in Bari, Italy on February 25, 2019. (Photo by De Giglio/Fotogramma/Ropi/ROPI via ZUMA Press/Rex Features/Shutterstock)

Indonesian soldiers take part in a handling riots practice ahead of the elections at their military home base in Banda Aceh, Aceh province on April 9, 2019. (Photo by Chaideer Mahyuddin/AFP Photo)

Participants in fancy costumes take part in march during the Prague Pride parade in downtown Prague, Czech Republic, 10 August 2019. Several thousands of people attended the 9th Prague Pride to support the LGBT (lesbian, gay, bisexual and transgender) communities. (Photo by Martin Divisek/EPA/EFE/Rex Features/Shutterstock)

Robots serve trays with food to customers waiting at the Robot theme restaurant in Bangalore, India, 17 August 2019. Six robots are deployed as waiters at the the robot-themed Robot restaurant where each table is equipped with a tablet to place one's order. (Photo by Jagadeesh N.V./EPA/EFE)

Costumed revellers perform in the parade during the Notting Hill Carnival in London, Monday, August 27, 2018. The carnival has been held every year since 1966 and one of the largest festival celebrations of its kind in Europe. (Photo by Tim Ireland/AP Photo)

Listed as endangered on the IUCN red list of threatened species, a humphead wrasse, or Napoleon fish, swims in an aquarium during an event in Tokyo's shopping district of Ginza on August 5, 2019. (Photo by Kazuhiro Nogi/AFP Photo)