A cafe-restaurant staff stands outside as people drink coffee in Monastiraki district of Athens, on Monday, May 25, 2020. Greece restarted regular ferry services to its islands Monday, and cafes and restaurants were also back open for business as the country accelerated efforts to salvage its tourism season. (Photo by Petros Giannakouris/AP Photo)

Noah, 10, cools himself off in his garden during hot weather in Hertford, Britain, June 25, 2020. The UK is experiencing a summer heatwave, with temperatures in many parts of the country expected to rise above 30°C and weather warnings in place for thunderstorms at the end of the week. (Photo by Andrew Couldridge/Reuters)

Two hippopotamus are fed with pumpkins at the Hanoi Zoo, in Hanoi, Vietnam, 25 October 2018. The zoo has been the home for more than 800 animals of over 90 different species, including three hippopotamus, since it was built in 1976. (Photo by Luong Thai Linh/EPA/EFE)

Iranian women sit in a bus in the capital Tehran on June 25, 2019. Iran's President Hassan Rouhani said today that new US sanctions against senior Iranian officials including top diplomat Mohammad Javad Zarif showed Washington is “lying” about an offer to negotiate. (Photo by Atta Kenare/AFP Photo)

A model presents a creation by designer John Galliano as part of his Spring/Summer 2020 women's ready-to-wear collection show for Maison Margiela during the Paris Fashion Week in Paris, France, September 25, 2019. (Photo by Gonzalo Fuentes/Reuters)

A man takes pictures at the finish line during the Colour Run at Centennial Park in Sydney August 25, 2013. According to organizers, 15,000 runners registered to complete the 5km (3 miles) course in Centennial Park on Sunday, being covered in blue, pink, orange and yellow powder on their way to the finish line. (Photo by Daniel Munoz/Reuters)

An enterprising Chinese man pulls a bicycle cart packed high with bags of recyclable plastic containers in Shanghai July 25, 2002. The man sells each kilogram (2.2 pounds) of plastic for 0.08 yuan ($.01) to a nearby depot. (Photo by Claro Cortes IV/Reuters)

Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)