In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

In this July 20, 2019 photo, children play during a sports event organized by members of the Caracas FC soccer club, in Catia, one of the poorest slums in Caracas, Venezuela. When the Caracas Football Club plays, its supporters leave their ideological preferences and socioeconomic differences behind, joining together to support and take care of each other inside and outside the stadium. (Photo by Matias Delacroix/AP Photo)

Soap Bubble Structures by Kym Cox. Bubbles optimise space and minimise their surface area for a given volume of air. This phenomenon makes them a useful tool in many areas of research, in particular, materials science and “packing” – how things fit together. Bubble walls drain under gravity, thin at the top, thick at the bottom, which interferes with travelling lightwaves to create bands of colour. Black spots show the wall is too thin for interference colours, indicating the bubble is about to burst. (Photo by Kym Cox/2019 Science Photographer of the Year/RPS)

Competitors take part in the annual Mud Madness event at Foymore Lodge on April 22, 2018 in Portadown, Northern Ireland. The adult version of the event includes two laps of an 8km course through 25 obstacles while the kids event is run over 2kms. The race is in it's eleventh year and is sponsored by McVities Jaffa Cakes and event charity partner Marie Curie together with other numerous charities and fundraising groups. (Photo by Charles McQuillan/Getty Images)

A family pose for a picture as thousands of redheads fill a Dutch city Breda to celebrate International Redhead Day event in Breda, The Netherlands on Sunday, 4 September 2016. Every year natural redheads from more than 80 countries come together at “Roodharigendag” annual weekend long festival to celebrate their ginger genes. The event also holds the world record for the largest number of natural redheads being in one place. (Photo by Akmen/London News Pictures)

A military aircraft flies low through the Mach Loop in west-central Wales on September 25, 2025 during Cobra Warrior 25-2, one of Nato’s largest multinational air exercises. The operation, running across the UK until October 3, brings together air forces from the UK, US, Canada, Italy and Germany for three weeks of high-intensity training in challenging low-level environments. (Photo by Tony Marsh)

A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)

Two visitors look at an artwork “Home Sweet Home: Pandemic Love 1” created by Hong Kong artist Mak Ying Tung at Art Basel in Hong Kong Wednesday, May 19, 2021. Art Basel, one of the world's most prestigious modern and contemporary art exhibitions, is returning to Hong Kong in its ninth edition. The prestige art fair is hosting 104 galleries from 23 countries and territories. (Photo by Vincent Yu/AP Photo)