St Louis County police officers arrest an anti-police demonstrator in Ferguson, Missouri August 10, 2015. Dozens of protesters were arrested on Monday afternoon after blocking rush-hour traffic on Interstate 70 a few miles (km) from Ferguson, Missouri, during demonstrations over the police shooting of an unarmed black man a year ago, according to a Reuters witness. (Photo by Lucas Jackson/Reuters)

A woman wearing a mask reacts at her garden which locates next to chimneys of coal-fired power plant in Shijiazhuang, Hebei province, China, January 28, 2015. Beijing introduced tougher regulations this year to combat pollution, keen to overhaul China's unwanted image of smog-choked cities, fouled waterways and heavy-metal tainted soil. (Photo by Kim Kyung-Hoon/Reuters)

In this picture taken on Sunday, March 5, 2017, a Tehran's urban animal control worker catches a stray dog after being shot with his anesthetic dart on the outskirts of the capital Tehran, Iran. The shelter has been hired by the Tehran city government to take a new, more humane approach to deal with the burgeoning problem of stray dogs in the capital. It’s a sign of changing attitudes among officials in a country where Islamic authorities long saw dogs as “un-Islamic” and would at times confiscate them from people who kept them as pets. (Photo by Vahid Salemi/AP Photo)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A Ballet Paraisópolis student wearing a face mask rehearses amidst the coronavirus (COVID-19) pandemic on August 13, 2020 in Sao Paulo, Brazil. The Ballet Paraisópolis is a project that teaches dance to children and young people in the Paraisópolis community in order to encourage them to seek better life opportunities. Founded in 2012 by ballerina, teacher and choreographer, Monica Tarragó, Ballet Paraisópolis has a total of 200 students and another 2,000 on the waiting list. (Photo by Alexandre Schneider/Getty Images)

A woman wearing a face mask takes a photo on her phone in Covent Garden, London, Thursday, December 3, 2020. Britain became the first country in the world to authorize a rigorously tested COVID-19 vaccine Wednesday and could be dispensing shots within days – a historic step toward eventually ending the outbreak that has killed more than 1.4 million people around the globe. (Photo by Alberto Pezzali/AP Photo)

An actor dressed as Santa Claus and wearing a face mask to protect against coronavirus infection speaks with a boy during the New Year celebration in a shopping mall in St.Petersburg, Russia, Saturday, January 2, 2021. (Photo by Dmitri Lovetsky/AP Photo)

A Sumatran elephant calf receives medical attention at the Saree elephant conservation centre in Saree, Aceh province on February 15, 2021, following the three week-old pachyderm's rescue in Pidie district after being stuck in mud. (Photo by Chaideer Mahyuddin/AFP Photo)