The ancient Chinese were the first to make silk. Chinese travellers took silk to other countries and traded it for other products. The route they followed is now know as the "Silk Road".
One-third of Earth's surface is covered by land. Most of this area is made up of huge land masses called continents. Islands occupy much less space. Water-oceans, lakes and rivers-covers the rest.
Mummies are preserved bodies. Egyptian mummies were buried. But some people's bodies became mummies by accident. Sometimes, the clothes they were wearing were also preserved!
Lizards belong to a group of animals called reptiles. There are all kinds: chameleons with sticky tounges that swat flies, marine iguanas that swim in the sea and basilisk lizards that run on water.
There are places on Earth where snow always covers the ground, and the seas are icy. These are the poles. The animals and people that live there have some unusual ways to cope with the cold.
Extreme is not ordinary. People and animals can survive in places that are Extremely hot, cold, wet or dry. Hurricanes, tornadoes, volcanoes and earthquakes can hit even the most ordinary places.
Space shuttles that travel to space are a very important modern invention. But older inventions, such as umbrellas and paper, have changed people's lives.
Birds have wings so that they can fly. But how have humans managed to fly? We flew in many machines before aeroplanes were invented. Read about what they were!
Earth's surface is mostly covered by water. Vast continents make up most of the land. The surface is changing all the time - mountains and islands grow out of the sea, while wind and water wear it away.
When pirates sailed the seas, they robbed ships for treasure and took their crews as prisoners. A pirate's life was exciting, but very dangerous. Pirates who were caught were punished cruelly.