Models promote a condom brand at the first Shenzhen s*x Culture Festival on September 21, 2007 in Shenzhen of Guangdong Province, China. The festival aims to increase awareness about reproductive health and popularise s*x education. (Photo by China Photos/Getty Images)

An Indonesian woman watches an eruption from the Mount Sinabung volcano from Tiga Pancur village, in Karo in North Sumatra on November 3, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity it erupted once more in 2013, and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

Highly commended, mammals: Gelada after the storm – Marco Gaiotti (Italy). “Gelada baboons are the only monkey species in the world that feed on grasses. They are native to the tableland of Ethiopia. Every morning large family groups wander from their sleeping places in the steep rock face, up to 1,000 metres high, to the feeding grounds at the tablelands. This image clearly depicts their feeding strategy: they pull out bunches of grass, sort the stalks and then lift them to their mouth. This shot was taken towards the end of the rainy season after a heavy storm”. (Photo by Marco Gaiotti/2019 GDT European Wildlife Photographer of the Year)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

A woman walks in front of an art installation made of artificial fruits and vegetables during the “Moscow Autumn” festival in central Moscow, September 14, 2015. (Photo by Maxim Zmeyev/Reuters)

Belarusian Sergei Selekh plays with his 6-month-old tamed wolves on the outskirts of the village of Gaina, 45 kilometers (28 miles) north of Belarus capital Minsk, Wednesday, December 31, 2014. Selekh owns a farmstead, where sheep, wolves and an ethnographic museum serve as entertainment for guests. (Photo by Sergei Grits/AP Photo)

An airplane is silhouetted at sunrise, seen from the suburb of Saint-Cloud, near Paris, France, 08 December 2016. Paris is undergoing a third day pollution spike, prompting the city to limit vehicle circulation. (Photo by Ian Langsdon/EPA)

The car driven by Scott Dixon, of New Zealand, goes over the top of Jay Howard, of England, in the first turn during the running of the Indianapolis 500 auto race at Indianapolis Motor Speedway, Sunday, May 28, 2017, in Indianapolis. (Photo by Marty Seppala/AP Photo)