Putting the Sun to WorkIt s a hot summer day, and you, your family, and friends decide to drive to
Its a hot summer day, and you, your family, and friends decide to drive to the beach for a cookout.
When you get to the beach, the sand and the rocks are so hot that they hurt your bare feet. You put on sneakers in a hurry. The water is so bright and shining in the sun that you can hardly look at it. While the charcoal (木炭) fire is starting to burn in the cookout stove, every one goes for a swim. The water feels good warm at the top, but cooler down around your toes.
A little wind is blowing when you come out. The fire isnt quite ready for cooking yet, so you play tag or read.
For lunch there are hot dog, corn, salad and rolls, sodas, fruit, and coffee for the adults. By the time the coffee water boils and the corn and hot dogs are cooked, all the bathing suits are dry. So are the towels spread out on the rocks, in the sun.
Lunch is good. Just as you are finishing, it starts to rain so you pack up and run. But nobody minds the rain. It will cool things off.
At the same time you were having fun at the beach, work was being done. Energy from the sun was doing work. Energy, in one form or another, does all the work in the world.
Heat energy from the sun dried the towels. It heated the sand and the rocks, the water and the air. It even made the rain and the wind. Heat from the sun does small work and big work, all over the earth.
Light energy from the sun was working on the beach too. It supplied the daylight.
It lit the earth and made the sand bright and the water sparkling.
The sun also supplied the energy that grew the food you ate.
Plants use light energy from the sun to make food for themselves. The food is a kind of sugar. It is also a kind of energy called chemical energy. Green plants change light energy from the sun into chemical energy.
Plants use some of that energy for everyday living and growing. They store the rest in their leaves and seeds, in fruit, roots, stems, and berries.
The salad and the corn, the rolls, fruit, and coffee all came from plants. You and all animals depend on plants for food.
The charcoal you used for cooking began as a plant too. Once, that charcoal was a living tree that used sunlight to make food and then stored part of the food it made. The energy in this stored food remained, even after the tree died. You used that energy when you burned the charcoal.
The gasoline you used for driving to the beach began with energy from the sun, too. It was made from oil.
Oil was formed from the remains of plants and animals that lived on earth millions of years ago. The remains of ancient living things are called fossils. This is why oil is called a fossil fuel. Coal and natural gas are fossil fuels, too.
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.
Is it possible to catch still more of the suns heat in a house? Yes, Some houses also collect heat on the roof, move it indoors, store some, use some to make hot water and the rest for heating. A house like that is called a solar house.
People who build solar houses have learned how to do those things by observing how the earth itself uses solar energy.
Remember the beach?
Remember the hot sand and the hot rocks?
Some materials take in heat energy from the sun and hold it. They absorb the heat. Sand and rocks do this. So do some other solid materials, such as metals. Water absorbs the suns heat too.
Color can also be important. Dark, dull colors absorb heat. Light-colored, shiny surfaces reflect heat. They bounce it back. Thats why dark clothes are warmer in the winter and light colored clothes are cooler in the summer.
The longer it takes something to heat up, the longer that thing holds the heat. Materials that heat up fast cool off fast.
If you go back to the beach in the evening after sunset, the sand and the rocks, which heated up fast, will be cool. But the water, which heated up slowly, will still be warm.
It takes a long time for the sun to heat the water in a big lake or ocean. But by the end of summer, a large body of water will have caught and stored enough heat from the sun to last for a good part of the winter. Water stores heat very well.
Thats why land near a large body of water never gets quite as cold in the winter as land far away from the water. The stored heat in the water keeps the land around it warm.
Slowly, all winter long, heat from the water moves out into the cold air. Heat always moves that way from a warmer place or thing to a cooler one. Once you know which way heat moves, you understand how things get hot and how they lose heat.
1. All the work in the world is done by energy coming from the sun in one form or another.
2. As we humans depend on plants for food, plants live on chemical energy converted from light energy.
3. Unless the sun dies, it will supply endless energy on earth.
4. It has been a long time since people began to use solar energy because sunshine can be stored in houses.
5. The advantage of the solar house is that it has hot water and heating.
6. A solar house doesnt have to use electricity when it makes a good use of solar energy.
7. The passage gives a brief account of how solar energy is employed.
8. We can understand how things get hot or lose heat as long as we know______.
9. Most of the energy the sun supplies to us is in the forms of______.
10. People like to use fossil fuels to get almost all kinds of energy because they are______.
答案:1. Y 2. Y 3. Y 4. N 5. N 6. NG 7. N 8. which way heat moves 9. heat and light 10. easy to use
国际英语资讯:Pakistan to form new agency to build tourist-friendly country
国际英语资讯:Chinese New Year reception held at U.S. Missouri governor mansion
婚前必问的12个问题 技术性排除潜在婚姻问题
体坛英语资讯:(Feature) How Dortmund preparing to face Bayerns attacks
国际英语资讯:Russian, U.S. diplomats to negotiate on New START extension: Putin
国内英语资讯:(Spring Festival) Across China: 2 minutes loving on the platform
国际英语资讯:No delays in Russian S-400 missiles delivery to Turkey: Erdogan
国内英语资讯:Chinese cities to introduce more convenience stores in 2019
国内英语资讯:Chinese envoy calls for support in combating maritime crime
体坛英语资讯:AFC Asian Cup: Jordan book first seat in knockouts, UAE get close by taming India
国内英语资讯:Xinhua Headlines: Made-in-China diamonds poised to shape global market
体坛英语资讯:AFC UAE 2019: China, S.Korea enter round of 16, Australia rebound
怎样区分英国人、法国人和德国人?
新年到!属猪的人本命年运势怎么样?
体坛英语资讯:Late penalty gives Barca cup lifeline after Valverde rests key players
国际英语资讯:4 Chinese tourists injured after bus overturns in Chiang Mai, Thailand
每日阅读的6大好处
娱乐英语资讯:Suzhou Orchestra brings Chinese folk music to Poland
国际英语资讯:Russia hopes Eurasian bloc signs FTA agreements with more countries
国际英语资讯:Britain witnesses hottest day of this year on Saturday
情绪一点就炸:被拒绝之前,我先拒绝你
国内英语资讯:(Spring Festival) Chinas inter-bank payment system passes severe test on Lunar New Years
体坛英语资讯:Winter training of Chinas national swimming team underway in SW China
国内英语资讯:Xinhua Headlines: Chinese New Year celebrations touch hearts around world
国际英语资讯:Trump nominates Treasury undersecretary Malpass to lead World Bank
国内英语资讯:Chinas railway trips up 8.6 pct in first 15 days of travel rush
体坛英语资讯:Iran beat Canada 3-0 in FIVB competition
体坛英语资讯:S. African striker Ndlovu vows to help Zhejiang Greentown promote to Chinese Super League
体坛英语资讯:Iraq cruise into knockout stage of AFC Asian Cup
体坛英语资讯:PSG to face Nimes in 2019-20 Ligue 1 opening round
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |