1大学英语四六级考试阅读提高练习题及答案(33)_大学英语阅读

1大学英语四六级考试阅读提高练习题及答案(33)

　　Now fossil fuels are beginning to be used up.

　　Thats why people worry about running out of energy.

　　But as long as the sun shines, the earth will not run out of energy. The sun pours more energy on earth than we can ever use. Most of that energy comes to us as heat and light. Energy from the sun is called solar energy.

　　Solar energy is a safe kind of energy. It doesnt make pollution or have dangerous leftovers. That is why scientists and inventors are experimenting with ways of harnessing the sun to do some of the jobs fossil fuels have been doing.

　　But to make the sun do work like that, they have to solve some problems.

　　They have to collect the suns energy. Collecting sunshine isnt easy, unless you are a plant.

　　Sunshine isnt easy to store, either. You cant fill a tank with it or put it in the wood box. You cant move it through a pipe or a wire. You cant turn it on.

　　Still, people have been using solar energy to help do their work for a long time. There are old ways and new ways of catching sunshine and putting it to work.

　　Suppose you were living in a cold place and going to spend the winter in a cave. Would you choose a cave that faced the winter sun or a cave that faced away from it?

　　You might make the same choice if you were building a house in a cold place. You would probably build the house, so the winter sun would pour in the windows to warm it. People have been building houses that way for a long time.