Earthquakes on the ocean floor can give a tremendous push to surroundings seawater and create one or more large, destructive waves called tsunamis, also known as seismic sea waves. Some people call
DNA (short for deoxyribonucleic acid) is the basic unit of control of human life. It is a highly complex substance formed from a chain of chemical units called nucleotides. All the the instructions for growing a
People are rapidly destroying the world's rain forests. In 1950, rain forests covered about 8,700,000 square miles (22,533,000 square km) of the earth. This area would cover about three-quarters of Africa. Today,
From a hazy mixture of history and legend, we learn that China's first ruling family was the Hsia. The legendary first emperors are said to have tamed the rivers, so that farmers could grow millet and wheat. The
In the AD 500s, an Italian named Benedict of Nursia drew up a set of rules for monks (or people in monasteries). All monks must be poor, unmarried and obedient. Monks wore simple robes, shaved their
Rome grew from a small kingdom in Italy. It became a republic and one of the mightiest empires of the ancient world, with an empire stretching the length of the Mediterranean Sea. At its peak, the Roman Empire
Egyptian picture-writing is known as HIEROGLYPHICS. This language is made up of about 750 signs, with pictures of people, animals and objects. until hieroglyphics was deciphered in modern times, it was not known that most of the picture represented sounds and syllables, not whole words. Scribes used a quick form of writing which was called hieratic. The Egyptians were also good in maths, particularly geometry, which they use in architecture and surveying. They drew up an accurate 12-month calendar of 365 days, and used water clocks to measure time.
More than 5,000 years ago Europeans were building spectacular stone monuments. Many of these are still standing today, as mysterious relics of a long-gone society. The huge stones that were used are called megaliths