The highway code contains rules concerning the safety equipment of bicycles.
The invention of the ballpoint pen made writing a lot easier.
Hero of Alexandria is the inventor of the first steam engine, although he regarded it as an entertaining toy.
The legendary M61 class locomotives of the Hungarian State Railways were manufactured by Nohab.
The main protagonists of World War II were tanks.
Paper was invented more than two thousand years ago.
The palace of Charlemagne was not only the centre of his empire, but also a centre of culture.
The apple is one of the most popular fruits around the world.
This animation demonstrates the mechanism and operation of record players.
An air conditioner cools the air inside by drawing heat away and releasing it outside.
Venus is the 2nd planet from the Sun, the brightest object on the night sky (after the Moon).
The dissolution of zinc in hydrochloric acid produces hydrogen gas.
Large-scale ammonia production requires high temperature and pressure and the presence of iron as a catalyst.
Farming techniques evolved with the development of human civilisation in the Middle Ages and the Modern Age.
Practise the Russian alphabet, build words from letters.
The mosque, built in a distinctive architectural style, is the largest adobe structure in the world.
Wind power stations convert the kinetic energy of the wind into electricity.
The limbic system plays an important role in forming emotions and in learning.
This 3D scene explains the correlation between the ratio of similarity and the ratio of volume of geometric solids.
Cossacks, members of independent semi-military communities, played an important role in the history of Ukraine.