The Earth is a rocky planet with a solid crust and oxygen in its atmosphere.
Certain mushrooms are poisonous and can be fatal for humans when consumed, while others are edible and used widely in cooking.
Human blood consists of blood cells and plasma.
Machines converting the energy of flowing or falling water into useful forms of power were already in use in the Middle Ages.
The huge dam built on the Colorado river in the US was named after a former American President.
Skeletal muscles form the active part of the locomotor system: they move the bones they are attached to.
In the Tudor Era around 200 buildings were built on the bridge across the River Thames.
The Parisian prison became legendary after the Revolution of 1789.
The seminomadic lifestyle of the Bedouin adapted to the climatic and environmental conditions of the desert.
Cannons also appeared in naval warfare.
The step pyramid, built in the 27th century BC, was the first pyramid in Egypt.
A series of fortifications built to prevent incursions from northern nomadic groups.
The position and acceleration of the head is detected by the inner ear.
The large intestine is the last section of our digestive track.
The ancient Roman arena became well-known for the chariot races held here.
The army of Alexander the Great successfully deployed siege towers in its attacks against fortifications.
The double-decked, wide-bodied passenger aircraft can carry more then 500 passengers.
This animation demonstrates the structure and operation of electron microscopes.
Nuclear fusion will serve as an environmentally friendly and practically unlimited source of energy.
One of the most modern means of transport is the Maglev, capable of travelling at speeds of over 400 km/h.