(L-R) Edmea Pereira, 69, Elsa Rodrigues, 61, and Osmidio Conde, 71, take part in their surf class in Santos, Sao Paulo state, Brazil, March 16, 2016. When work is up, surf is up in Brazil, as a group of retired citizens take to the waves in keep-fit, keep-young sessions at a surf school in the city of Santos. The classes are run for free, three times a week at the Cisco Arana school, which aims to prove that age is just a number. (Photo by Nacho Doce/Reuters)

Animal rights activists, including musician Kris Reichert, center, hold up signs with writing in Italian reading; “Leather: a lethal look” and “I wouldn't wear animal skin even if I were dead” as they stage a demonstration in front of Milan's Duomo gothic cathedral, Italy, Wednesday, September 20, 2017. Milan Fashion Week previews kick off Wednesday with Gucci, leading up to the awards on Sunday night. (Photo by Luca Bruno/AP Photo)

A supporter of the presidential candidate for the Honduran Opposition Alliance Against the Dictatorship for the past election, Salvador Nasralla, lies on the street in front of police officers during a demonstration against the contested re-election of President Juan Orlando Hernandez, in Tegucigalpa, Honduras on January 21, 2018. (Photo by Orlando Sierra/AFP Photo)

This February 7, 2018, photo shows João Lousada, a flight controller for the International Space Station, wearing an experimental space suit during a simulation of a future Mars mission in the Dhofar desert of southern Oman. The desolate desert in southern Oman resembles Mars so much that more than 200 scientists from 25 nations organized by the Austrian Space Forum are using it for the next four weeks to field-test technology for a manned mission to Mars. (Photo by Sam McNeil/AP Photo)

Photographer Gregg Segal travelled the world to document children and the food they eat in a week. Partly inspired by the increasing problems of childhood obesity, he tracked traditional regional diets as yet unaffected by globalisation, and ironically, found that the healthiest diets were often eaten by the least well off. (Photo by Gregg Segal/The Guardian)

A rat being trained by the Cambodian Mine Action Centre (CMAC) is pictured on an inactive landmine field in Siem Reap province July 9, 2015. Gambian pouched rats were deployed to Cambodia from Tanzania in April by a Belgian non-profit organization, APOPO, to help clear mines. They've been trained since they were 4 weeks old. Cambodia is still littered with landmines after emerging from decades of civil war, including the 1970s Khmer Rough “Killing Fields” genocide, leaving it with one of the world's highest disability rates. APOPO has used the rodents for mine-clearing projects in several countries, including Angola, Mozambique, Thailand, Laos, and Vietnam. (Photo by Samrang Pring/Reuters)

Some companies in Taiwan spend months building temples with bricks and cement, but Lin Fu-Chun's firm simply pours concrete into a giant mould and waits for it to dry. The 78-year-old Lin said his temple factory, Chuanso, needed just over six weeks to finish a building that normally took six months with conventional methods – and moulding was 40 percent cheaper. Here: An employee paints a ready-made Chinese traditional temple at the Chuanso factory that manufactures religious objects in Pingtung, Taiwan July 5, 2016. (Photo by Tyrone Siu/Reuters)

A man reacts after catching a trout with his hands during an event promoting the Ice Festival on a frozen river in Hwacheon, about 20 km (12 miles) south of the demilitarized zone separating the two Koreas, January 10, 2015. The annual ice festival, which is one of the most famous and biggest festivals in South Korea, expects to see more than 1,000,000 people attend. The festival lasts for three weeks from January 10 this year. (Photo by Kim Hong-Ji/Reuters)