The ruler of the vast Mongol Empire was the Khan.
A type of rotary engine of high efficiency
The church consecrated to Saint Basil was commissioned by Ivan the Terrible.
This effective strategy was based on the fast and synchronised attack of different branches of the army.
The German engineer Otto Lilienthal was the first person to make successful flights with a glider designed by himself.
The Incas´ rudimentary weapons were inadequate in their struggle against the Spanish Conquistadors.
The Byzantine Emperor was the head of the Byzantine Empire, the direct continuation of the Roman Empire.
As opposed to opencast mines, in underground mines the layers covering coal are not removed, coal is extracted from mine shafts.
The Aztec Empire was a despotic, militaristic state ruled by the tlatoani.
A spacecraft on its path is in a constant state of free fall.
This animation demonstrates how a CRT television works.
The river and marine sailing boats of ancient Egypt were one-masted, oared boats
Dung dịch hòa tan của hydro clorua trong nước được gọi là axit clohydric.
Entertaining and spectacular animation to practise orientation in space.
The two main parts of the central nervous system, the brain and the spinal cord are protected by the skull and the spinal column.
Bones of the lower limbs are connected to the trunk by the pelvis.
The earliest version of the lute appeared in ancient Mesopotamia.
The naval battle fought by the British Navy against the German Navy was the largest sea battle in World War I.
Solomon's temple became one of the most important symbols of Jewish architecture.
This animation demonstrates how mobile phones work.