Cera

Human being use energy to warm themselves and to make things move. The first people who walked the earth, before the discovery of fire, could not use some of the source of energy that we use today.They had the sun’s heat to providen warmth, but when they wanted to make things move, they and only their own bodies to help them. Later, humans learned to use the energy stored in wood to make firesfor heat and light. They used the energy of horses, donkeys, and camels for transporting themselves and for hauling loads. The Egyptians harnessed the energy of the wind by making sails for theirboats. And ancient peoples learned to use t6he energy of falling water to turn wheels that could grid grain. Thus, fire, animals, wind and water were sources of energy that made people lives easier inearlier times.
Today, we used energy from electric power plants, fuels like oil and gasoline and other source. We can fly, to London, England, in some hours, using energy from fuel in a jet engine. Wecan wash and dry clothes using dryers. We can read a book or play a tennis match long after the sun has gone down by electric lights. All these things are possible because of energy. But We pay a pricefor using all this energy. We use up the coal and oil store beneath the earth, and when we burn them we put harmful materials into our air and water.
From the core knowledge series
Humanos el usode energía para calentarse y para hacer mover las cosas. Las primeras personas que caminaron por la tierra, antes del descubrimiento del fuego, no podía utilizar algunas de las fuentes de energía queusamos hoy en día. Tenían calor del sol para providencial calor, pero cuando quisieron hacer mover las cosas, y sólo sus propios cuerpos para ayudarlos. Más tarde, los humanos aprendieron a utilizarla energía almacenada en la madera para hacer fuego para el calor y la luz. Ellos usaron la energía de los caballos, burros y camellos para transportar ellos mismos y para transportar cargas. Los...