A man wearing a “Pinhead” mask walks through the grounds of St Mary's Church, Whitby, during the Whitby Gothic festival taking place this weekend, on April 27, 2014. The twice yearly event attracts Goths from across the UK and beyond to the historic fishing town and is a great boost to the local economy. (Photo by Anna Gowthorpe/PA Wire)

A tour group wanders through block 7 of Eastern State Penitentiary in Philadelphia, Pennsylvania April 30, 2014. Opened in 1829, with the original corrective system of “confinement in solitude with labor”, the penitentiary housed about 75,000 inmates in its 142 years of operation. At Eastern State reunions, former inmates, staff and guard gather to share memories and trade stories and get a chance to describe their experiences in question-and-answer sessions with the public. (Photo by Mark Makela/Reuters)

In this April 20, 2018, file aerial photo released by China's Xinhua News Agency, advection fog drifts across skyscrapers on the waterfront in Qingdao in eastern China's Shandong Province. Chinese leaders have long been sensitive about their communist country’s international image. Now, they are battling back, investing in diplomacy and a courtship of hearts and minds, just as the United States digs in on the Trump administration’s “America First” mindset. (Photo by Lu Hui/Xinhua via AP Photo/File)

National Police members disinfect Venezuelan citizens returning to the country from Colombia, as a preventive measure against the spread of the coronavirus –COVID19- at the Simon Boliviar International Bridge, in Cucuta, Colombia-Venezuela border, on April 4, 2020. Since the first case of COVID-19 was detected last March 6, Colombia has reported 1,406 people infected and 32 dead. (Photo by Schneyder Mendoza/AFP Photo)

People walk along Beachy Head, close to Eastbourne on the south coast of England on April 12, 2020, as life in Britain continues over the Easter break, during the nationwide lockdown to combat the novel coronavirus pandemic. Britain's Prime Minister Boris Johnson was making “very good progress” on Saturday in his recovery in hospital from coronavirus, officials said, as the country's deaths toll from the disease approached the grim milestone of 10,000. (Photo by Ben Stansall/AFP Photo)

Seven-year-old Mimi Meade winces from the sting as Dr. Richard Mulvaney inoculates her April 26, 1954 in McClean, Va., with the new Salk polio vaccine. Mrs. John Lucas, a registered nurse, holds Mimi's arm steady as she gets one of the first injections of the countrywide test. (Photo by Harvey Georges/AP Photo)

This picture taken on April 12, 2017 shows men carrying bamboo through a forest near Dashan village near the city of Lin'an, Zhejiang Province. Lin'an is in a area of eastern Zhejiang province whose rich bamboo forests are estimated to supply up to two-thirds of China's bamboo shoots, plus a range of other products derived from the fast-growing plant that are produced both for domestic and overseas markets. (Photo by Johannes Eisele/AFP Photo)

In this photo taken on Saturday, April 22, 2017, a drawing “King for a day” is made on the back of a muddy truck by artist Nikita Golubev in Moscow, Russia. The grimy trucks traversing the polluted and dusty streets of Moscow have inspired Golubev to use white vans and trucks as his canvas to create this ephemeral street art and signs his drawings Pro Boy Nick. (Photo by Pavel Golovkin/AP Photo)