山東 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(xué)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

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

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

3The landscape is located in East Antarctica's Wilkes Land area bordering the Indian Ocean.The researchers said the landscape appears to date to at least 14 million years ago and perhaps beyond 34 million years ago, when Antarctica entered its deep freeze.

4“It is difficult to know what this lost world might have looked like before the ice came along, but it was certainly warmer back then,” said Stewart Jamieson, a professor of glaciology at Durham University.“Depending on how far back in time you go, you might have had climates that ranged anywhere from the climate of present-day Patagonia through to something more approaching tropical.Such an environment likely would have been populated by wildlife,” he added.But the area's fossil record is too incomplete to know which animals may have lived there.

5The 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 drill through the ice and take a piece of the earth below.This could uncover evidence showing ancient life, as was done with samples taken in Greenland dating back two million years ago.

6Jamieson 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 broke away.“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

Detail1.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.

Inference2.Why is it hard to know Antarctica's 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.

Inference3.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 Antarctica's earth surface below the ice.

Detail4.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

continentn.大陸

glaciersn.冰川

Greenlandn.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 just ice like today.Scientists found old land 2.________(shape) like hills and valleys under Antarctica'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 Antarctica got super cold.“We don't know much about this buried land, but a long time ago,5.________ could have had warm weather and animals.However, we don't have enough old bones to tell 6.________ kind of animals lived there.We know more about Mars's ground 7.________ the earth under Antarctica's ice.If we drill into the ice and take dirt from below, we may find signs of old life like scientists did 8.________ Greenland with very 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 got colder, 10.________(keep) the old land shapes the same for a long time.