Cossacks, members of independent semi-military communities, played an important role in the history of Ukraine.
Practise the German alphabet and form words from the letters.
Structures consisting of enormous stone blocks, dating back thousands of years, are monuments of megalithic cultures.
The range of applications of unmanned aerial vehicles ('drones') keeps growing.
The development of mosses, ferns, gymnosperms and angiosperms is characterised by the alternation of generations.
This scene presents the location, anatomy and functioning of the central organ of the human circulatory system.
Frank Lloyd Wright's well-known work is a masterpiece of modern organic architecture.
This 3D scene presents the flora and fauna of the last period of the Palaeozoic Era.
This 3D scene presents the steps of the cement manufacturing process.
The vacuum cleaner creates a partial vacuum and sucks up dust with the help of the incoming high-pressure air.
By positron emission tomography (PET), we can obtain visual information on our internal organs without making any surgical incisions.
Practise the English alphabet, build words from letters.
Enzymes are protein molecules catalysing biochemical reactions. Their activity can be regulated.
This scene explains the structure and functions of the bones.
The adrenal glands are responsible for maintaining homeostasis and producing a rapid response in stressful situations.
There are two basic cell types: prokaryotic and eukaryotic cells.
Practise the Russian alphabet, build words from letters.
Colourless, odourless liquid produced by dissolving carbon dioxide in water.
A polynucleotid made up of phosphoric acid, ribose, and nucleobases (cytosine, uracil, adenine and guanine).
This stunning castle is situated in northern Croatia.