The Great Wall of China is the biggest object ever made by humans. It stretchesacross mountains, deserts and grasslands for over 6,000 kilometres. The ancientChinese built the wall to keep invaders from the west out of their country. Today tourists from all over the world come and see it. The Great Wall began as a series of many smaller walls that were […]
Babies born in the United States in 2005 are expected to live an average of 77.9 years, according to a 2007 study. That’s an increase of more than 30 years since 1900, when Americans were expected to live just 47.3 years. The increase is big, but America is not at the top of the list for life expectancy. Actually, the United States ranks behind 41 other […]
Florida is the southernmost state on the US mainland. It is a peninsula that borders on Georgia and Alabama in the north, the Atlantic Ocean in the east and the Gulf of Mexico in the west. The state has a land area of about 140,000 square kilometres and more than 10,000 square kilometres of water surface. Florida got its name from the Spanish explorer Juan Ponce […]
South Africa lies at the southern end of the African continent, where the Atlantic and Indian oceans come together. For a long time in the past centuries South Africa was governed by whites, although about 80 % of the population are blacks. In the 1990s the election of the first black president , Nelson Mandela opened a newchapter of South African history. Size and […]
An earthquake is one of the worst natural disasters on our earth. We think that the ground we stand on is very stable, but it isn’t. It moves quite a lot. In the last fewdecades scientists have been able to find out why earthquakes happen. Earthquakes happen when there is a sudden vibration in the earth’s crust. It’s like a large lorry that travels […]
When a volcano erupts hot gases and liquid rock come up to the surface from inside the earth. The material sometimes slides down mountains as lava or ishurled into the air as ash or small rocks. Volcanoes often destroy the land around them completely. Gases from eruptions can keep sunlight from reaching the earth and darken the sky for years. Volcanoes also build up new islands and […]
Hurricanes are gigantic tropical storms that can be hundreds of kilometres wide . They bring along very strong winds and a lot of rainfall. They often cause floodingnear the coasts and sea levels rise . Hurricanes occur in many parts of the world. In the Pacific Ocean they are called typhoons and in Australia they are willy-willies. In the Atlantic Ocean and the Caribbean Sea they are […]
A desert is a hot area of land that gets very little rain—not more than 200 mm a year. Temperatures during the daytime can get as high as 55° C. At night, deserts cool down, sometimes even below 0° C. Deserts cover about 20% of the world’s land. The biggest is the Sahara desert, which is about the same size […]
Developed countries use up about 80 % of the world’s energy. Today, the United States has about 5% of the world’s population but consumes one fourth of the world’s energy. A person in a developing country uses only about a fifteenth as much energy as someone in the industrialized world. Country % of Energy Consumed % of Energy Produced United States 25 […]
Turn lights off if you don’t need them. When possible, use energy saving light bulbs (or fluorescent lamps) Don’t overheat you house. Set the thermostat to about 21 ° C and use a fan instead of air conditioning to cool down rooms during the summer. Make sure that windows and doors are closed. Newly built buildings and houses should […]