Members of team China perform during the Artistic Swimming Team Free Final at the FINA Swimming World Championships in Gwangju, South Korea, 19 July 2019. (Photo by Antonio Bat/EPA/EFE/Rex Features/Shutterstock)

Hotel staff practice self-defence skills after a training session given by team member of Special Weapons and Tactics (SWAT) team, in Hangzhou, Zhejiang province, April 7, 2016. (Photo by Reuters/Stringer)

Workers stir hundreds of large ceramic pots as they spend months making a traditional soy sauce on October 14, 2020. Arranged in rows, the containers can hold up to 50 litres of Ban Soy sauce. During the drawn out process the sauce is stirred every two days for two to six months. Ban Yen Nhan village in the Hung Yen Province of Vietnam is famous for its traditional and distinctive method of making the sauce. (Photo by Nguyen Quy/Solent News)

A woman carrying a bundle on her head wait in line to cross the border into Colombia through the Simon Bolivar bridge in San Antonio del Tachira, Venezuela, Sunday, July 17, 2016. Tens of thousands of Venezuelans crossed the border into Colombia on Sunday to hunt for food and medicine that are in short supply at home. It's the second weekend in a row that Venezuela’s government has opened the long-closed border connecting Venezuela to Colombia. (Photo by Ariana Cubillos/AP Photo)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)

A jogger is seen running at Hampstead Heath with London in the background on June 1, 2021. Britain sees temperatures increasing for the second day in a row after the mercury hit 25C (77 Fahrenheit) for the warmest day of the year so far on Bank Holiday Monday. (Photo by Joshua Bratt/London News Pictures)