As opposed to opencast mines, in underground mines the layers covering coal are not removed, coal is extracted from mine shafts.
Radial engines are used primarily in airplanes and helicopters.
This animation demonstrates different types of soil.
Capacitors store electrical energy in the form of electric charge.
The church consecrated to Saint Basil was commissioned by Ivan the Terrible.
Movie theaters were built in large numbers in big cities of the U.S. in the 1910s.
Metal atoms form a regular lattice structure.
A rock relief located in Northeast Bulgaria, probably carved at the end of the 7th century.
The withdrawal reflex is a spinal reflex that ensures moving away from potentially damaging stimuli.
The inability to differentiate certain shades of color is called color vision deficiency.
A long pipe in the center of the tower penetrates the ocean bed until it reaches the layer that contains oil.
An ancient Greek myth about the tragedy of father and son who wanted to flee the island of Crete.
This Neoclassical structure is one of the best-known landmarks of Berlin and Germany.
The architecture of traditional Samoan family settlements reflect the unique culture of their inhabitants.
The dromedary is an indispensable animal for inhabitants of the deserts.
The building complex was one of the most important Benedictine abbeys for centuries.
This animation demonstrates how a refrigerator works.
The French monarch got his epithet because of his opulent and extravagant lifestyle.
A type of herbivorous dinosaur easily recognizable by its large frill and three horns which lived in the Cretaceous period.
Adrenaline, also known as epinephrine, is a hormone produced in our bodies in stressful situations and plays an important role in the fight-or-flight response.