Students wearing mask hold hands to surround the St. Stephen's Girls' College in Hong Kong, Monday, September 9, 2019. Thousands of demonstrators in Hong Kong urged President Donald Trump to “liberate” the semiautonomous Chinese territory during a peaceful march to the U.S. Consulate on Sunday, but violence broke out later in the business and retail district as police fired tear gas after protesters vandalized subway stations, set fires and blocked traffic. (Photo by Kin Cheung/AP Photo)

A woman cries while being escorted by police officers during an anti-government protest in Santiago, Chile, 07 November 2019. A proposed increase in the price of metro fares sparked a series of anti-government protests that have left at least 20 people dead. The protestors are demanding improvements in the quality of healthcare, education and general distribution of wealth in Chile. (Photo by Orlando Barría/EPA/EFE)

Sina prepares for the reopening of the latex fashion shop Savage Wear as the coronavirus disease (COVID-19) lockdown measures are eased in Berlin, Germany, March 9, 2021. (Photo by Hannibal Hanschke/Reuters)

A baby Asian elephant, born only two days before, stands next to his mother Nova in its enclosure at Tierpark Berlin Zoo on May 10, 2012 in Berlin, Germany. The male elephant calf, who does not have a name yet, weighs 102kg and is 91cm tall. (Photo by Timur Emek/dapd/Sean Gallup)

Northern Lynx kittens, explore their enclosure at the Highland Wildlife park on October 9, 2012 in Kingussie, Scotland. The feline twins are believed to be the type of lynx found historically in Scotland. The Highland Wildlife Park specialises in Scottish animal species, both past and present, and species that are well adapted to cold weather. (Photo by Jeff J. Mitchell)

An Army Sikorsky VH-34s Choctaw helicopter once used to transport President Dwight D. Eisenhower sits in a field at the 309th Aerospace Maintenance and Regeneration Group boneyard Thursday, May 14, 2015 at Davis-Monthan Air Force Base in Tucson, Ariz. President Eisenhower became the first chief executive to be transported by helicopter. Presidents Eisenhower and John F. Kennedy were transported in VH-34 helicopters and VH-34's served as “Army One” from 1958 through 1963. (Photo by Matt York/AP Photo)

A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. The world's largest aircraft has been unveiled for the first time since being fully assembled in the UK. The 302ft (92m) long Airlander 10 – part plane, part airship – was floated in a First World War hangar in Bedfordshire. (Photo by Darren Staples/Reuters)

Skiers and snow boarders descend from a slope as they attempt to break the record for mass skiing in swimming suits at Rosa Khutor resort near Sochi, Russia, April 9, 2016. (Photo by Kazbek Basayev/Reuters)