Raw iron is produced from iron ore in iron smelters.
English sailing ships were among the best ships in the 17th-19th centuries.
Concave and convex lenses are used for the correction of short-sightedness and far-sightedness.
Treated sewage water can be used in agriculture and industry.
As opposed to underground mines, in open-pit mines the layers covering coal are removed, coal is extracted on the surface.
Spanish conquerors owed their success to their armour and firearms.
Tidal power stations utilise the daily fluctuation of the water level for producing electricity.
This animation demonstrates instruments used to examine atmospheric phenomena.
Keeps were typical buildings in the Middle Ages, also built independently from castles.
Satellites orbiting the Earth can be used for civilian or military purposes.
The purpose of the electricity supply network is to provide electricity for consumers.
The Space Shuttle was a manned, reusable spacecraft operated by NASA.
The staggered conformation of ethane is more stable than the eclipsed conformation.
Electrochemical processes in a lead-acid battery produce electric current.
One of the most common types of flatworms.
Learn the concept of colours, numbers, letters and shapes while playing
This animation demonstrates several types of prisms, from general to regular.
This animation demonstrates the construction of motorcycles.
Combine harvesters are machines that harvest and thresh grain crops.
A type of settlement that has central functions.