This animation demonstrates birds' bones and eggs through the example of the common blackbird.
An acyl-carrier coenzyme taking part in both anabolic and catabolic processes.
Colour a map with the fewest number of colours possible, so that no two adjacent regions have the same colour.
American soldiers fought in almost all major theatres of World War II.
Caliphs, considered successors of the Prophet Muhammad, were the most important religious leaders of Islam.
Ancient Persian monarchs were famous for the size of their empire and their wealth.
Christian kings played an important role in medieval history.
Maharajas were Hindu rulers of large regions of India.
This animation demonstrates the relative position of lines and planes.
This animation demonstrates the angle of inclination of lines and planes in various positions.
This animation demonstrates various types of cones and pyramids.
An exercise about the generation of solids of revolution.
Soldiers of the Wehrmacht in World War II were well-trained and well-equipped with modern weapons.
This animation demonstrates the states and largest cities of the USA.
The Arch of Triumph was built at the entrance of the Forum Romanum, to commemorate Emperor Titus’ victory in the Siege of Jerusalem.
The Altar of Peace, commissioned during the reign of Augustus, was one of the most important works of ancient Roman art.
The Ironsides were members of the Parliamentarian cavalry formed by Oliver Cromwell during the English Civil War.
A zither is one of the typical instruments of Hungarian folk music, played by strumming or plucking the strings.
Ancient Indian war elephants were used as 'tanks' in battles.
The masterpiece of Buddhist architecture is located in India.