Red deer are even-toed ungulates, ruminants. Their males have spectacular antlers.
Honeybees produce a sweet and nutritious substance, honey.
The river and marine sailing boats of ancient Egypt were one-masted, oared boats
An ant colony consist of a queen, male ants and workers.
The migration of large human populations began in Ancient times.
The diameter of our galaxy is about 100,000 light years; it contains more than 100 billion stars, one of which is our Sun.
The water supply system provides clean and safe drinking water for the consumers.
Two meshing gears transmit torque during their rotational motion.
Igloos were the typical dwellings built by Eskimos living in the Arctic zone.
This animation demonstrates the main sources of air pollution: agriculture, industry and urban settlements.
NAD⁺ is a coenzyme that plays an important role mainly in catabolic processes, while NADP is important in anabolic processes as hydrogen carriers.
The ruler of the vast Mongol Empire was the Khan.
Careful tooth brushing is an important part of oral hygiene.
To calculate the volume of a tetrahedron we start by calculating the volume of a prism.
A hot air balloon is a balloon aircraft which is lifted by hot air.
The bell is a percussion instrument and an idiophone. Many types of bells exist.
The cockchafer (or maybug) is a widespread bug in Europe. Its larvae, known as chafer grubs are considered a pest.
Domesticated animals and crops originate from various parts of the world.
The battle ended with the overwhelming victory of the Macedonian army over the Persian army led by Darius III.
Oases are areas in deserts where water is available.