An undercover police officer, who had been marching with anti-police demonstrators, aims his gun at protesters after some in the crowd attacked him and his partner in Oakland, California December 10, 2014. Police said more than 100 demonstrators marched in Berkeley, California, which has a history of social activism. Under cloudy skies, turnout was smaller than earlier in the week, when demonstrators in the area threw rocks at police and shut down a major freeway. (Photo by Noah Berger/Reuters)

This picture taken on July 15, 2014 shows a bridge submerged in floodwaters in the ancient town of Fenghuang, central China's Hunan province. Rainstorms lashed central China's Hunan Province and southwest China's Guizhou Province, affecting over 1 million people and flooding a historical town, state media reported. (Photo by AFP Photo)

Commuters interact with an elephant as he rests in a public road ahead of the annual Perahera festival of the historic Gangaramaya Temple in Colombo on February 18, 2019. Some 50 elephants, most of them from the central area of Kandy along with thousands of traditional drummers, dancers, and monks have gathered in the Sri Lankan capital to participate in the city's biggest two-day annual Buddhist Navam procession, scheduled for February 18-19. (Photo by Ishara S. Kodikara/AFP Photo)

Young Lebanese women wearing protective masks and gloves against the coronavirus pandemic, stand on August 5, 2020 amid the rubble in Beirut's Gimmayzeh commercial district which was heavily damaged by the previous day's powerful explosion that tore through Lebanon's capital, resulting from the ignition of a huge depot of ammonium nitrate at the city's main port. Rescuers searched for survivors in Beirut after a cataclysmic explosion at the port sowed devastation across entire neighbourhoods, killing more than 100 people, wounding thousands and plunging Lebanon deeper into crisis. The blast, which appeared to have been caused by a fire igniting 2,750 tonnes of ammonium nitrate left unsecured in a warehouse, was felt as far away as Cyprus, some 150 miles (240 kilometres) to the northwest. (Photo by AFP Photo/Stringer)

A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944

English pop singer Shane Fenton, later known as Alvin Stardust, autographing a woman's leg in his dressing room. (Photo by John Pratt/Keystone Features/Getty Images). September 1962

A sign reading “STOP Danger of Avalanches” blocks a local road on January 11, 2012 near Ischgl, Austria. Over the last few days heavy snowfalls have caused chaos in parts of Austria and Switzerland by blocking rail and road connections, stranding vacationers at mountain ski resorts and creating the risk of avalanches throughout the region. (Photo by Johannes Simon/Getty Images)

A woman photographs a Norwegian spruce Christmas tree from Oslo after it was lit at Trafalgar Square in central London, December 4, 2014. (Photo by Toby Melville/Reuters)