Train attendants take part in a parade training as they visit the national flag guard during a patriotic education event ahead of the 90th anniversary of the founding of the Chinese People's Liberation Army (PLA) in Beijing, China July 25, 2017. (Photo by Reuters/China Stringer Network)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

An ultra-Orthodox Jewish bride takes part in the “mitzva tantz”, the custom in which relatives dance in front of the bride after her wedding ceremony, in Netanya, Israel, early March 16, 2016. (Photo by Baz Ratner/Reuters)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)

A woman jumps out of a street art object in the center of the Ukrainian capital of Kiev during a warm autumn day on September 25, 2020. (Photo by Sergei Supinsky/AFP Photo)

Regrowth of plants is seen in bushland that was destroyed by bushfires, in Kulnura, New South Wales, 15 January 2020. (Photo by Joel Carrett/EPA/EFE/Rex Features/Shutterstock)

Houses near Taal Volcano's crater are seen buried in volcanic ash from the volcano's eruption on January 14, 2020 in Taal Volcano Island, Batangas province, Philippines. The Philippine Institute of Volcanology and Seismology raised the alert level to four out of five, warning that a hazardous eruption could take place anytime, as authorities have evacuated tens of thousands of people from the area. An estimated $10 million worth of crops and livestock have been damaged by the on-going eruption, according to the country's agriculture department. (Photo by Ezra Acayan/Getty Images)

An OV-10 Bronco aircraft, decorated with World War One commemoration motifs, flies over Flanders international airport, ahead of the world's first Short Take Off & Landing competition on sand, in Wevelgem, Belgium May 8, 2018. (Photo by Francois Lenoir/Reuters)