In this September 27, 2017 file photo, girls walk past a wall riddled with bullet holes from shootings between rival drug traffickers, at the Rocinha slum, in Rio de Janeiro, Brazil. Violence is on the rise in Rio's slums after several years of decline, and the killings of kids have shocked even residents long inured to deaths from gangs and police. (Photo by Silvia Izquierdo/AP Photo)

Russian cadet preparing before the International Kremlin Cadet Ball in Moscow, Russia 12 December 2017. More than 1500 students from all Russian cadets school attend in Cadet Ball. (Photo by Yuri Kochetkov/EPA/EFE)

A kite flying contest is held in Nantong, east China's Jiangsu featuring various kites of different shapes on December 20, 2017. (Photo by SIPA Asia/Pacific Press/Barcroft Images)

Employee Jenny Forgie works on an orchid display at Kew Gardens in London, Thursday, February 8, 2018. The 23rd annual Orchid Festival is the first one with a Thailand theme, 66 volunteers worked on the 6,950 exhibited orchids. The festival is open from Feb. 10, 2018 until March 11, 2018. (Photo by Frank Augstein/AP Photo)

Hotel ushers pose for a photo at Tiananmen Square as delegates attend the second plenary session of the National People's Congress (NPC) in Beijing, China, March 9, 2018. The CPPCC is the top advisory body of the Chinese political system and runs alongside the annual plenary meetings of the 13th National People's Congress (NPC), together known as “Lianghui” or “Two Meetings”. (Photo by Jason Lee/Reuters)

A traffic police officer directs traffic in Mohe City, northeast China's Heilongjiang Province, December 29, 2019. Temperatures in Mohe, “north pole” of China, often stand at below minus 40 degrees Celsius in winter mornings. Photo by Yang Siqi/Xinhua News Agency/Alamy Live News)

A man sets himself on fire during protest rallies in front of the presidential office in Kiev, Ukraine on February 26, 2020. The man, who called himself Oleksandr Burlakov, said subsequently that his motive was to draw the attention of the authorities to his plight, related to the ownership of the land parcel. (Photo by Ihor Behus/Reuters)

A woman wearing a face mask as a precaution against the COVID-19 while using smartphone in a subway train in Hong Kong, Thursday, February 27, 2020. As the worst-hit areas of Asia continued to struggle with a viral epidemic, with hundreds more cases reported Thursday in South Korea and China, worries about infection and containment spread across the globe. (Photo by Kin Cheung/AP Photo)