Event curators Harry Parr (L) and Sam Bompas (R) sit in paddle boats in the Truvia Voyage of Discovery installation on the roof of Selfridges department shop on July 21, 2011 in London, England. Selfridges is opening its roof to the public for only the second time since WW2 to host the installation, which includes a boating lake with dyed water and bar. (Photo by Matthew Lloyd/Getty Images)

Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

A man runs away during a police round up of suspected drug addicts in Kabul, Afghanistan December 27, 2015. Afghan officials have opened a new drug treatment centre in an abandoned NATO military base in Kabul, in the latest attempt to stamp out the country's massive problem of drug abuse. Camp Phoenix, a former training camp on the edges of Kabul set up by the U.S. army in 2003, will take in around 1,000 homeless drug addicts who will receive food, medical attention and treatment, said Public Health Minister Ferozuddin Feroz. (Photo by Ahmad Masood/Reuters)

A view of a large poster depicting Russian opposition leader Alexei Navalny behind bars with a dove freeing him from detention, by an unidentified street artist known as Harry Greb, in downtown Rome, Italy, 25 January 2021. Navalny was detained after his arrival to Moscow from Germany on 17 January 2021. A Moscow judge on 18 January ruled that he will remain in custody for 30 days following his airport arrest. Navalny urged Russians to take to the streets to protest against President Putin's rule. (Photo by Fabio Frustaci/EPA/EFE)

Two baby orangutans play with each other at the wildlife department in Kuala Lumpur, Malayasia, October 19, 2015. The Malaysian wildlife department in July seized two baby Sumatran orangutans, found in duffel bags, from traffickers who were attempting to sell them to buyers in Malaysia. According to local media, the orangutans will be returned to Medan, Indonesia on Tuesday. The illegal wildlife trade is estimated to be $8 billion a year worldwide, according to TRAFFIC, a wildlife trade monitoring network. (Photo by Olivia Harris/Reuters)

Two styles of cleaned bird's nest, Yan Zhan (L) and Su Zhan (R) await repacking at a processing plant in Kuala Lumpur, February 17, 2015. Prized in China for is alleged health benefits for hundreds of years, nests made from swiftlets' saliva are being mixed into coffee and cereal as the Southeast Asian producers of the delicacy seek to broaden its appeal, and their profit margins. The nests are among the world's most expensive foods, selling for up to $2,500 a kg and the swiftlets that weave them are indigenous to Indonesia, Malaysia, Thailand and Vietnam. (Photo by Olivia Harris/Reuters)