高级英语第一册Unit 3 文章结构+课文讲解+课文翻译+课后练习+答案文档格式.docx

1、- I was standing in the sun on the hot steel deck of a fishing ship capable of processing a fifty-ton catch on a good day. But it wasn t a good day. We were anchored in what used to be the most productive fishing site in all of central Asia, but as I looked out over the bow , the prospects of a good

2、 catch looked bleak. Where there should have been gentle blue-green waves lapping against the side of the ship, there was nothing but hot dry sand as far as I could see in all directions. The other ships of the fleet were also at rest in the sand, scattered in the dunes that stretched all the way to

3、 the horizon . Ten year s ago the Aral was the fourth-largest inland sea in the world, comparable to the largest of North Americas Great Lakes. Now it is disappearing because the water that used to feed it has been diverted in an ill-considered irrigation scheme to grow cotton In the user t. The new

4、 shoreline was almost forty kilometers across the sand from where the fishing fleet was now permanently docked. Meanwhile, in the nearby town of Muynak the people were still canning fish brought not from the Aral Sea but shipped by rail through Siberia from the Pacific Ocean, more than a thousand mi

5、les away.My search for the underlying causes of the environmental crisis has led me to travel around the world to examine and study many of these images of destruction. At the very bottom of the earth, high in the Trans-Antarctic Mountains, with the sun glaring at midnight through a hole in the sky,

6、 I stood in the unbelievable coldness and talked with a scientist in the late tall of 1988 about the tunnel he was digging through time. Slipping his parka back to reveal a badly burned face that was cracked and peeling, he pointed to the annual layers of ice in a core sample dug from the glacier on

7、 which we were standing. He moved his finger back in time to the ice of two decades ago. Heres where the U. S Congress passed the Clean Air Act, ” he said. At the bottom of the world, two continents away from Washington, D. C., even a small reduction in one countrys emissions had changed the amount

8、of pollution found in the remotest end least accessible place on earth.But the most significant change thus far in the earth s atmosphere is the one that began with the industrial r evolution early in the last century and has picked up speed ever since. Industry meant coal, and later oil, and we beg

9、an to burn lots of it bringing rising levels of carbon dioxide （CO2） , with its ability to trap more heat in the atmosphere and slowly warm the earth. Fewer than a hundred yards from the South Pole, upwind from the ice runway where the ski plane lands and keeps its engines running to prevent the met

10、al parts from freeze-locking together, scientists monitor the air sever al times ever y day to chart the course of that inexorable change. During my visit, I watched one scientist draw the results of that days measurements, pushing the end of a steep line still higher on the graph. He told me how ea

11、sy it is there at the end of the earth to see that this enormous change in the global atmosphere is still picking up speed.Two and a half years later I slept under the midnight sun at the other end of our planet, in a small tent pitched on a twelve-toot-thick slab of ice floating in the frigid Arcti

12、c Ocean. After a hearty breakfast, my companions and I traveled by snowmobiles a few miles farther north to a rendezvous point where the ice was thinner only three and a half feet thick and a nuclear submarine hovered in the water below. After it crashed through the ice, took on its new passengers,

13、and resubmerged, I talked with scientists who were trying to measure more accurately the thickness of the polar ice cap, which many believe is thinning as a re-suit of global warming. I had just negotiated an agreement between ice scientists and the U. S. Navy to secure the re-lease of previously to

14、p secret data from submarine sonar tracks, data that could help them learn what is happening to the north polar cap. Now, I wanted to see the pole it-self, and some eight hours after we met the submarine, we were crashing through that ice, surfacing, and then I was standing in an eerily beautiful sn

15、owcape, windswept and sparkling white, with the horizon defined by little hummocks, or pressure ridges of ice that are pushed up like tiny mountain ranges when separate sheets collide. But here too, CD, levels are rising just as rapidly, and ultimately temperature will rise with them indeed, global

16、warming is expected to push temperatures up much more rapidly in the polar regions than in the rest of the world. As the polar air warms, the ice her e will thin; and since the polar cap plays such a crucial role in the worlds weather system, the consequences of a thinning cap could be disastrous.Co

17、nsidering such scenarios is not a purely speculative exercise. Six months after I returned from the North Pole, a team of scientists reported dramatic changes in the pattern of ice distribution in the Arctic, and a second team reported a still controversialclaim （which a variety of data now suggest）

18、 that, over all, the north polar cap has thinned by 2 per cent in just the last decade. Moreover, scientists established several years ago that in many land areas north of the Arctic Circle, the spring snowmelt now comes earlier every year, and deep in the tundra below, the temperature e of the eart

19、h is steadily rising.As it happens, some of the most disturbing images of environmental destruction can be found exactly halfway between the North and South poles precisely at the equator in Brazil where billowing clouds of smoke regularly black-en the sky above the immense but now threatened Amazon

20、 rain forest. Acre by acre, the rain forest is being burned to create fast pasture for fast-food beef; as I learned when I went there in early 1989, the fires are set earlier and earlier in the dry season now, with more than one Tennessees worth of rain forest being slashed and burned each year. Acc

21、ording to our guide, the biologist Tom Lovejoy, there are more different species of birds in each square mile of the Amazon than exist in all of North America which means we are silencing thousands of songs we have never even heard.But one doesnt have to travel around the world to wit-ness humankind

22、s assault on the earth. Images that signal the distress of our global environment are now commonly seen almost anywhere. On some nights, in high northern latitudes, the sky itself offers another ghostly image that signals the loss of ecological balance now in progress. If the sky is clear after suns

23、et - and it you are watching from a place where pollution hasnt blotted out the night sky altogether - you can sometimes see a strange kind of cloud high in the sky. This noctilucent cloud occasionally appears when the earth is first cloaked in the evening dark-ness; shimmering above us with a trans

24、lucent whiteness, these clouds seem quite unnatural. And they should: noctilucent clouds have begun to appear more often because of a huge buildup of methane gas in the atmosphere. （Also called natural gas, methane is released from landfills , from coal mines and rice paddies, from billions of termi

25、tes that swarm through the freshly cut forestland, from the burning of biomass and from a variety of other human activities. ） Even though noctilucent clouds were sometimes seen in the past., all this extra methane carries more water vapor into the upper atmosphere, where it condenses at much higher

26、 altitudes to form more clouds that the suns rays still strike long after sunset has brought the beginning of night to the surface far beneath them.What should we feel toward these ghosts in the sky? Simple wonder or the mix of emotions we feel at the zoo? Perhaps we should feel awe for our own powe

27、r: just as men ear tusks from elephants heads in such quantity as to threaten the beast with extinction, we are ripping matter from its place in the earth in such volume as to upset the balance between daylight and darkness. In the process, we are once again adding to the threat of global warming, b

28、e-cause methane has been one of the fastest-growing green-house gases, and is third only to carbon dioxide and water vapor in total volume, changing the chemistry of the upper atmosphere. But, without even considering that threat, shouldnt it startle us that we have now put these clouds in the eveni

29、ng sky which glisten with a spectral light? Or have our eyes adjusted so completely to the bright lights of civilization that we cant see these clouds for what they are a physical manifestation of the violent collision between human civilization and the earth?Even though it is sometimes hard to see

30、their meaning, we have by now all witnessed surprising experiences that signal the damage from our assault on the environment -whether its the new frequency of days when the temperature exceeds 100 degrees, the new speed with which the -un burns our skin, or the new constancy of public debate over w

31、hat to do with growing mountains of waste. But our response to these signals is puzzling. Why havent we launched a massive effort to save our environment? To come at the question another way Why do some images startle us into immediate action and focus our attention or ways to respond effectively? A

32、nd why do other images, though sometimes equally dramatic, produce instead a Kin. of paralysis, focusing our attention not on ways to respond but rather on some convenient, less painful distraction?Still, there are so many distressing images of environ-mental destruction that sometimes it seems impossible to know how to absorb or comprehend them. Before considering the threats themselves, it may be helpf