Girls practice sit-ups during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, on May 4, 2016. China's sports system has been enormously successful since the country returned to the Olympic fold in 1980, culminating with the host nation topping the medals' table at the 2008 Beijing Olympics. And yet, with the Rio de Janeiro Games less than three months away, the system is beginning to break down due to the shifting demographics of a more prosperous nation. (Photo by Aly Song/Reuters)

These black-and-white photos are taken from the new book “Armoured Warfare in the First World War 1916 – 1918” by Anthony Tucker-Jones and published by Pen & Sword Military. Here: British troops hitch a ride on a Mark IV after the massed tank fleet spearheading attack at Cambrai on November 20, 1917. (Photo by Anthony Tucker-Jones/Mediadrumworld.com)

Beautiful, strange and occasionally alarming pictures from the shortlist for this year’s Wellcome image awards – which celebrate the very best in science photography and imaging – from an x-ray of a bat to a micrograph of a kidney stone. The exhibition opens on 12 March at three science centres and the Museum of Science and Industry in Manchester. Photo: Scanning electron micrograph (SEM) of an Arabidopsis thaliana flower, also commonly known as thale cress. Some of the anthers are open, revealing pollen grains ready for dispersal. Arabidopsis was the first plant to have its entire genome sequenced and is widely used as a model organism in molecular and plant biology. Horizontal width of image is 1200 microns. Magnification 100x. (Photo by Stefan Eberhard/Wellcome Images)

The Waitomo Glowworm Caves attraction is a cave at Waitomo on the North Island of New Zealand, known for its population of glowworms, Arachnocampa luminosa. This species is found exclusively in New Zealand. They are around the size of an average mosquito. This cave is part of the Waitomo Caves system that includes the Ruakuri Cave and the Aranui Cave.

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4. Its specific gravity is between 3.5 and 3.7. It crystallizes in the trigonal system, and cleaves with rhombohedral carbonate cleavage in three directions.

A model wears an Apache costume in the kids carnival during The 13th Jember Fashion Carnival 2014 on August 21, 2014 in Jember, Indonesia. The 13th Jember Fashion Carnival (JFC) 2014 theme is “Triangle, Dynamic in Harmony” and consists of ten parades which include Mahabharata, Tambora, Phoenix, Pine Forest, Apache, Borobudur, Flying Kite, Wild Deers, Stalagmite, and Chemistry. This street carnival is claimed to be one of the biggest in the world and comprises more than 850 performers parading along 3.6 km road used as the catwalk. (Photo by Robertus Pudyanto/Getty Images)

Extraordinary tales of everyday heroism have been illustrated beautifully by renowned US photographer Steve McCurry in the new 2015 Lavazza Calendar. The calendar which has been created in collaboration with the Slow Food movement, features twelve breathtaking pictures, capturing the spirit, strength and humanity of the Earth Defenders – women and men who protect their land and projects in Africa with passion and bravery. The proceeds from sales of the calendar and all donations will be contributed entirely to create 10,000 food gardens in African schools and villages by the end of 2016. (Photo by Steve McCurry/2015 Lavazza Calendar)

Ivar Rodningem is a professional illustrator, whose imaginative mind transports us into a parallel world where trolls roam the lands. These creatures might seem scary at first sight, but in reality they are very docile and friendly, help each other and humans that they happen to meet. One of their characteristic features is of course their large noses and long tails. They are one with the nature, which is why it is almost impossible to see a troll if he doesn’t want to be found. Just like you and I they love having fun, though it is hard thing to do, considering their size.