This picture taken on June 1, 2019 shows Alex Gao trying to balance a book on his head during an etiquette and manners class in central Shanghai. Against a soundtrack of classical music, children learn social skills, dining manners and deportment in the class, which costs $390 for four hours of practical instruction per student. (Photo by Hector Retamal/AFP Photo)

Indian students smear coloured powder during an event to celebrate the Hindu festival of Holi in Kolkata on February 26, 2018. Holi, the popular Hindu spring festival of colours is observed in India at the end of the winter season on the last full moon of the lunar month, and will be celebrated on March 1 this year. (Photo by Dibyangshu Sarkar/AFP Photo)

A combination of pictures shows people taking photos of themselves in Tiananmen Square as they celebrate National Day marking the 67th anniversary of the founding of the People's Republic of China, in Beijing October 1, 2016. (Photo by Damir Sagolj/Reuters)

A general view of atmosphere during 2016 New York Comic Con – Day 1 on October 6, 2016 in New York City. The annual event offers pop culture fans exhibitors and displays of popular video games, movies and comic books and many people attending dress as their favorite character. (Photo by Daniel Zuchnik/Getty Images)

A voodoo believer, dressed as "Gede", a spirit of voodoo, sits on the cross of Baron Samdi during celebrations at the cemetery of Port-au-Prince, Haiti, November 1, 2016. Voodoo believers and devotees offer candles, alcohol and food. The Day of the Dead is celebrated on the first two days of November during All Saints and All Souls Day. (Photo by Andres Martinez Casares/Reuters)

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

Anti-pollution protesters wearing traditional costumes and contemporary gas masks ride bicycles in the Qingming Grand river park in Kaifeng, Henan Province, China on January 1, 2017. The Beijing Municipal Environmental Protection Bureau extended an “orange alert” for heavy air pollution for three more days. (Photo by SIPA Asia/Rex Features/Shutterstock)