The Earth is divided into geographical and climatic zones, which result in the zonation of vegetation.
This animation demonstrates the mechanism and operation of record players.
The boundaries of tectonic plates can be seen on the seafloor.
Neptune is the outermost planet of the Solar System, the smallest of the giant planets
The topmost layer of our skin is the epidermis, which contains melanocytes.
Submarines had an important role in naval warfare as early as World War I.
In alkaline batteries electric current is generated by electrochemical reactions
One of the oxoacids of nitrogen. A colourless compound with a pungent odour, a strong oxidant.
DC motors consist of a permanent magnet and a coil within the magnet, with electric current flowing in it.
An important endocrine gland producing hormones that affect metabolism and the calcium balance of the body.
A sphere is the set of points which are all within the same distance from a given point in space.
Common ciliated eucaryotic unicellular organisms widespread in freshwaters.
This animation demonstrates various types of cylindrical solids as well as their lateral surfaces.
The suspension bridge that stretches above the strait between San Francisco Bay and the Pacific Ocean was opened in 1937.
The solution of hydrogen chloride in water is called hydrochloric acid.
Treated sewage water can be used in agriculture and industry.
The first dwellings in human history provide a lot of information about the lifestyle of our ancestors.
Neurons are cells specialised for transmitting electric signals.
The urinary system serves for the removal of harmful and useless materials from the body.
The changing bicycle, at first mocked as a toy, is a true mirror of the technical development over the last three centuries.