Opposition students march against Venezuelan President Nicolas Maduro's government in Caracas February 12, 2015. Venezuelan troops blocked students during marches against Maduro on Thursday as pro-government supporters also rallied on the anniversary of 2014 protests that led to 43 deaths. In Caracas, troops cordoned off scores of students on an unauthorized march to a church where they planned a mass in honour of demonstrators who died. (Photo by Jorge Silva/Reuters)

Monumental landscape artwork “Hush” by installation artist Steve Messam hangs in the moors of Teesdale on July 18, 2019 in Barnard Castle, England. The outdoor installation is inspired by the geology, mining history and landscape of the area. It hangs over Bales Hush, a deep gauge in the terrain created when miners flushed the area with water to reveal the geological riches below. Hundreds of metres of recyclable saffron yellow fabric blow in the wind. (Photo by Christopher Thomond/The Guardian)

Demonstrators clash with members of the Bolivarian National Police as protests continue in Caracas, Venezuela, 20 April 2017. The Bolivarian National Guard, using tear gas, tried to disperse protests against the government of Venezuelan President Nicolas Maduro. (Photo by Miguel Gutierrez/EPA)

A military guard observes from a watch tower at the Combinado del Este prison during a media tour in Havana, Cuba, Tuesday, April 9, 2013. Cuban authorities led foreign journalists through the maximum security prison, the largest in the Caribbean country that houses 3,000 prisoners. Cuba says they have 200 prisons across the country, including five that are maximum security. (Photo by Franklin Reyes/AP Photo)

Members of the British Thai celebrate the Thai New Year (Songkran) at the Buddhapadipa Temple on April 16, 2018 in London, England. Buddhapadipa Temple, the largest Thai temple in the UK with religious ceremonies Thai classical music and dancing performances as well as stalls selling Thai food, groceries and souvenirs. (Photo by Paul Quezada-Neiman/Alamy Live News)

In this April 16, 2019 photo, people wait to be given empty water containers and water purification pills during the first aid shipment from the Red Cross in Caracas, Venezuela. In late March, the Red Cross federation announced it would soon begin delivering assistance to an estimated 650,000 people and vowed that it would not accept interference from either side of the polarized country. (Photo by Ariana Cubillos/AP Photo)

Russian honor guard soldiers warm up prior a rehearsal for the Victory Day military parade in St. Petersburg, Russia, Wednesday, May 3, 2017. The parade will take place at Dvortsovaya (Palace) Square on May 9, to celebrate 72 years after the victory in WWII. (Photo by Dmitri Lovetsky/AP Photo)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)