Dancers prepare before a performance in the backstage area of the Buick exhibition during the “Auto China 2014” Beijing International Automotive Exhibition in Beijing on April 21, 2014. Leading automakers have gathered in Beijing for the kickoff of China's biggest car show, but lackluster growth and environmental restrictions in the world's largest car market have thrown uncertainty into the mix. (Photo by AFP Photo)

A member of the Fuerza Civil (Civil Force) police unit takes part in a simulated crime situation during a media presentation to show the police model that the federal government wants for the rest of the country, at the police academy in Monterrey December 17, 2014. Fuerza Civil, a tactical team of the police unit trained by the army, was created by the Nuevo Leon government in 2011 to curb down corruption and infiltration by drug gangs in the police corps, local media reported. Promising a new law to stop the infiltration of local governments by organized crime, President Enrique Pena Nieto pledged to reform the penal system and send an proposal to Congress to unify multi-layered police forces in Mexico's 31 states. (Photo by Daniel Becerril/Reuters)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Muslim pilgrims pray around the holy Kaaba at the Grand Mosque, during the annual haj pilgrimage in Mecca September 30, 2014. (Photo by Muhammad Hamed/Reuters)

A healthcare worker dressed as Santa Claus distributes gifts to children at the Ayeyarwady Covid Centre in Mandalay, Myanmar, on December 25, 2020, Christmas Day, amid the Covid-19 pandemic, caused by the novel coronavirus. (Photo by Ye Aung Thu/AFP Photo)

A shopkeeper wears a face mask as a precaution against the coronavirus waits for customers at a market in Bengaluru, India, Friday, November 20, 2020. India's total number of coronavirus cases since the pandemic began has crossed 9 million. Nevertheless the country's new daily cases have seen a steady decline for weeks now and the total number of cases represents 0.6% of India's 1.3 billion population. (Photo by Aijaz Rahi/AP Photo)

A man being tested for the COVID-19 novel coronavirus reacts as a medical worker takes a swab sample in Wuhan in China's central Hubei province on April 16, 2020. China has largely brought the coronavirus under control within its borders since the outbreak first emerged in the city of Wuhan late last year. (Photo by Hector Retamal/AFP Photo)

Final-year student Alina Repkina prepares for a livestream of the Last Bell ceremony for school leavers at secondary school No 11 in Rostov-On-Don, Russia on May 30, 2020. It is the first time in Russia that such ceremonies have been held via video link due to the coronavirus lockdown restrictions. (Photo by Valery Matytsin/TASS)