listenthisway3答案及原文.docx

1、listenthisway3答案及原文listen-this-way-3答案及原文Unit 1Part I Getting readyA.B. Keys:1: burning of the forests/tree removal (deforestation)/reduction of the worlds rain forests2: global warming/greenhouse effect/emissions of CO2Part II The Earth at risk (I)A. Keys:1.a. More people-more firewood-fewer treesb

2、. More domestic animals-more plants-fewer available plantsa, b- More desert-move south-desrtt expanding south-no grass2. Growing crops stabilize soil, without them the top soil just blows away. But if there isnt enough rain the crops dont grow.3. People try to grow food to support themselves or to c

3、reate ranches where cattle can be raised, or to get hardwood for export, or to make way for an iron ore mineB. Keys:1: Sahara Desert2: North America & most of Europe3: top soil blowing away4: tropical forests destruction5: animal/plant species becoming extinct6: climate change for the whole worldPar

4、t III The Earth at risk (II)A. Keys:1: Trees would hold rainfall in their roots. When forests in the higher up-river have been destroyed, all the rain that falls in the monsoon season flows straight into the river and starts the flooding.2: He implies that some national governments just consider the

5、 results of their policies in the near future, or just think as far ahead as the next election.B. Keys:Dary reports.Part II The Earth at risk (I)A.I (Interviewer): Brian Cowles is the producer of a new series of documentaries called The Earth at Risk which can be seen on Channel 4 later this month.

6、Each program deals with a different continent, doesnt it, Brian?B (Brian Cowles): Thats right. We went to America, both North and South and then we went over to Africa and South-East Asia.I: And what did you find in each of these continents?B: Starting with Africa, our film shows the impact of the p

7、opulation on the environment. Generally speaking, this has caused the Sahara Desert to expand. Its a bit of a vicious circle we find. People cut down trees for firewood and their domestic animals eat all the available plants and so consequently they have to move south as the Sahara Desert expands fu

8、rther south. I mean, soon the whole of Mali will become a desert. And in East Africa: here the grasslands are supporting too many animals and the result is, of course, theres no grass nothing for the animals to eat.I: I see. And the next film deals with North America?B: Thats right. In the USA, as y

9、ou know, intensive agriculture requires a plentiful supply of rain for these crops to grow, I mean if there isnt enough rain the crops dont grow. And growing crops stabilize soil, without them the top soil just blows away. This is also true for any region that is intensely farmed most of Europe, for

10、 example.I: And what did you find in South America?B: In South America (as in Central Africa and Southern Asia) tropical forests are being cut down at an alarming rate. This is done so that people can support themselves by growing food or to create ranches where cattle can be raised to be exported t

11、o Europe or America as tinned meat. The problem is that the soil is so poor that only a couple of harvests are possible before this very thin soil becomes exhausted. And it cant be fed with fertilizers like agricultural land in Europe.For example, in Brazil in 1982 an area of jungle the size of Brit

12、ain and France combined was destroyed to make way for an iron ore mine. Huge numbers of trees are being cut down for exports as hardwood to Japan, Europe, USA to make things like luxury furniture. These forests cant be replaced the forest soil is thin and unproductive and in just a few years, a jung

13、le has become a waste land. Tropical forests contain rare plants (which we can use for medicines, for example) and animals one animal or plant species becomes extinct every half hour. These forest trees also have worldwide effects. You know, they convert carbon dioxide into oxygen. The consequence o

14、f destroying forests is not only that the climate of that region changes (because there is less rainfall) but this change affects the whole world. I mean, over half the worlds rain forest has been cut down this century.Part III The Earth at risk (II)A.I: So, Brian, would you agree that what we gener

15、ally think of as natural disasters are in fact man-made?B: Yes, by and large. I mean, obviously not hurricanes or earthquakes, but take flooding, for example. Practically every year, the whole of Bangladesh is flooded and this is getting worse. You know, the cause is that forests have been cut down

16、up in Nepal and India, I mean higher up-river in the Himalayas. Trees would hold rainfall in their roots, but if theyve been cut down all the rain that falls in the monsoon season flows sraight into the river Ganges and floods the whole country. The reason for flooding in Sudan is the same the fores

17、ts higher up the Blue Nile in Ethiopia have been destroyed too.I: Well, this all sounds terribly depressing. Um . What is to be done? I mean, can anything be done, in fact?B: Yes, of course it can. First, the national governments have to be forward-looking and consider the results of their policies

18、in ten or twenty years, not just think as far ahead as the next election. Somehow, all the countries in the world have to work together on an international basis. Secondly, the population has to be controlled in some way: there are too many people trying to live off too little land. Thirdly, we dont

19、 need tropical hardwood to make our furniture its a luxury people in the West must do without. Softwoods are just as good, less expensive and can be produced on environment-friendly tree farms, where trees are replaced at the same rate that they are cut down.I: And, presumably, education is importan

20、t as well. People must be educated to realize the consequences of their actions?B: Yes, of course.I: Well, thank you, BrianB.I: So, Brian, would you agree that what we generally think of as . er. as er . natural disasters are in fact man-made?B: Yes, by and large . er . I mean, obviously not hurrica

21、nes or earthquakes, but take flooding, for example. I mean, practically every year, the whole of Bangladesh is flooded and this is getting worse. You know, the cause is that forests have been cut down up in Nepal and India . I mean . higher up-river in the Himalayas. Trees .er . would hold rainfall

22、in their roots, but if theyve been cut down all the rain that falls in the monsoon season flows straight into the river Ganges and floods the whole country. The reason for flooding in Sudan is the same the forests higher up the Blue Nile in Ethiopia have been destroyed too.I: Well, this all sounds t

23、erribly depressing. Um . what is to be done? I mean, can anything be done, in fact?B: Yes, of course it can . er . first, the national governments have to be forward-looking and consider the results of their policies in ten or twenty years, not just think as far ahead as the next election. Somehow,

24、all the countries in the world have to work together on an international basis. Secondly, the population has to be controlled in some way: there are too many people trying to live off too little land. Thirdly, we dont need tropical hardwood to make our furniture its a luxury people in the West must

25、do without. Softwoods are just as good, less expensive and can be produced on environment-friendly tree farms, where trees are replaced at the same rate that they are cut down.I: And, presumably, education is important as well. People must be educated to realize the consequences . um . of their acti

26、ons?B: Yes, yes of course.I: Well, thank you, Brian.Part IV More about the topic: The Effects of Global WarmingThe world is warming up. We know this because average temperatures are the highest since scientists started measuring them 600 years ago. The increase is about 0.2 every year. This may seem

27、 very slight, but we know that slight changes in temperature can have a big effect on other things. Most scientists now believe this global warming is due to human activity.Jeff Jenkins is head of Britains Climate Prediction Center. He explains how global warming can happen.Sunlight strikes the eart

28、h and warms it up. At the same time heat leaves the earth, but part of that is trapped by carbon dioxide and other gases in the earths atmosphere. That has been happening ever since the earth was formed. But the fear is that increasing amounts of carbon dioxide produced by industrial processes and t

29、ransport and so on will lead to a greater warming of the earths surface. So thats the golbal warming that people are concerned about.People are most concerned about the use of fossil fuels. Fossil fuels are oil, coal, wood and so on. When these burn, they produce the gas carbon dioxide. Many scienti

30、sts agree that an increase in the amount of carbon dioxide and some of the gases in the atmosphere will increase the amount of warming. Computers are being used to predict what this may mean. They showed that there could be great changes in rainfall and the rise in the sea level as ice caps in the n

31、orth and south poles melt. This could have a serious effect on agriculture according to Prof. Martin Perry of University College in London. He says it could become more difficult to grow food in the tropics at lower latitudes nearer to the equator.The most clear pattern emerging is the possibility o

32、f reduced potential production in lower latitude regions, and most generally speaking, increased potential in higher latitude regions. Lower latitude regions are already warm, to put it extremely simply, and plants there are quite near their limits of heat and drought stress. An increase in temperature or reduction in moisture would place limits on crop