Antarctica was once home to rivers and forests南極洲：失落的世界

李全忠

南極洲并不總是一片荒涼的冰雪之地，這塊地球最南端的大陸曾經(jīng)是布滿河流和森林、孕育著生命的家園?？茖W家們利用衛(wèi)星觀測和雷達影像，一睹南極洲——失落的世界。

主題語境：人與自然 篇幅：330詞 建議用時：6分鐘

1 Antarctica has not always been a land of ice and snow. Earth＇s southernmost continentonce was home to rivers and forests full of life.

2 Scientists are using satellite observations and radarimagery to look deep under the ice. The researchers reportedfinding a large ancient landscape buried under thecontinents ice sheet. It is full of valleys and ridges （山脊），shaped by rivers before being covered by glaciers long ago.

3 The landscape is located in East Antarcticas WilkesLand area bordering the Indian Ocean. The researchers said the landscape appears to dateto at least 14 million years ago and perhaps beyond 34 million years ago， when Antarcticaentered its deep freeze.

4“ It is difficult to know what this lost world might have looked like before the icecame along， but it was certainly warmer back then，” said Stewart Jamieson， a professor ofglaciology at Durham University.“ Depending on how far back in time you go， you mighthave had climates that ranged anywhere from the climate of present?day Patagonia throughto something more approaching tropical. Such an environment likely would have been populatedby wildlife，” he added. But the areas fossil record is too incomplete to know whichanimals may have lived there.

5 The researchers said the surface of the planet Mars is better known than the earth surface below the ice in Antarctica. They said one way to learn more would be to drillthrough the ice and take a piece of the earth below. This could uncover evidence showingancient life， as was done with samples taken in Greenland dating back two million years ago.

6 Jamieson said the researchers think that when Antarctica＇s climate was warmer，rivers flowed toward a continental coastline that was created as the other land masses brokeaway.“ When the climate cooled， some small glaciers formed on hills next to the rivers.When the climate cooled even more， an ice sheet grew which covered the whole continent，the landscape got preserved， likely for 34 million years，” Jamieson said.

Reading Check

Detail

1. What do we know about the landscape？

A. It is located in the center of Antarctica.

B. It＇s discovered by radar observations.

C. It was once a warmer area than it is now.

D. It has a history of less than 14 million years.

Inference

2. Why is it hard to know Antarcticas past looks according to Jamieson？

A. There is no complete fossil record.

B. The ice sheet of Antarctica melts quickly.

C. Scientists lack enough advanced equipment.

D. Climate conditions vary greatly from place to place.

Inference

3. Why is the planet Mars mentioned in paragraph 5？

A. To attract more scientists to Antarctica.

B. To strengthen the importance of Mars.

C. To show the great challenges the researchers faced.

D. To say people know little about Antarcticas earth surface below the ice.

Detail

4. What made the landscape get preserved for such a long time？

A. The colder climate.

B. Continental coastlines.

C. Other land masses reduction.

D. Less populated areas by wildlife.

Language Study

Ⅰ. 日積月累

continent n.大陸

glaciers n. 冰川

Greenland n. 格陵蘭

satellite observation 衛(wèi)星觀測

radar imagery 雷達影像

ancient landscape 古老的地貌

ice sheet 冰蓋

valleys and ridges 山谷和山脊

Indian Ocean 印度洋

ancient life 古代生命

continental coastline 大陸海岸線

land masses 大陸塊

break away 分裂開來

Ⅱ. 語法填空

Long ago， Antarctica 1.________（have） warm weather with rivers and trees， not justice like today. Scientists found old land 2.________（shape） like hills and valleys underAntarctica＇s ice by 3.________（use） space cameras and radar. This 4.________（hide）land is near the Indian Ocean and could be up to 34 million years old. It formed before Antarcticagot super cold.“ We dont know much about this buried land， but a long time ago，5.________could have had warm weather and animals. However， we don＇t have enoughold bones to tell 6.________kind of animals lived there. We know more about Mars＇sground 7.________the earth under Antarctica＇s ice. If we drill into the ice and take dirtfrom below， we may find signs of old life like scientists did 8.________Greenland withvery old ice，” Professor Stewart Jamieson said. He also thought rivers 9.________（be）there when Antarctica was warmer， and as land moved apart， the coastline changed. First，small ice pieces started to form， and then a big ice sheet covered everything when it gotcolder， 10.________（keep） the old land shapes the same for a long time.