A monkey is led by its trainer Qi Defang during training for a circus in Suzhou, Anhui province, November 29, 2014. Suzhou is known as the hometown of circus troupes in China and has more than 300 circus troupes. (Photo by William Hong/Reuters)

A boy crawls under a cow during a religious ceremony celebrating the Tihar festival, also called Diwali, in Kathmandu, October 23, 2014. Hindus all over Nepal are celebrating the festival during which they worship cows, which are considered a maternal figure, and other animals. Also known as the festival of lights, devotees worship the goddess of wealth Laxmi by illuminating and decorating their homes using garlands, oil lamps, candles and colourful light bulbs. (Photo by Navesh Chitrakar/Reuters)

Tourists take a “selfie” as demonstrators burn a trash container during a May Day rally in Barcelona, Spain, on May 1, 2014. Tens of thousands of workers marked May Day in European cities with a mix of anger and gloom over austerity measures imposed by leaders trying to contain the eurozone's intractable debt crisis. (Photo by Manu Fernandez/Associated Press)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

A street vendor sells sliced fruits during a pro-government rally in Caracas, Venezuela, June 21, 2016. (Photo by Mariana Bazo/Reuters)

Women with their faces painted as various Hindu deities take part in a celebration a day after the first democratic constitution was announced in Kathmandu, Nepal September 21, 2015. Nepal adopted its first full democratic constitution on Sunday, a historic step for a nation that has witnessed war, a palace massacre and devastating earthquakes since a campaign to create a modern state began more than 65 years ago. (Photo by Navesh Chitrakar/Reuters)

A performer dances at a housing exhibition in Wuhan, Hubei province, China, September 27, 2015. (Photo by Reuters/Stringer)

Graduates jump as they pose for photographs in front of the Tiananmen Gate and the giant portrait of late Chinese Chairman Mao Zedong, on the Tiananmen Square in Beijing, June 19, 2014. (Photo by Reuters/Stringer)