雅思閱讀第040套P2-Antarctica - in from the cold?
READING PASSAGE 2
You should spend about 20minutes on Questions 14-26, which are based on Reading Passage2 below.
Antarctica - in from the cold?
A A little over a century ago, men ofthe ilk of Scott, Shackleton and Mawson battled against Antarctica’s blizzards,cold and deprivation. In the name of Empire and in an age of heroic deeds theycreated an image of Antarctica that was to last well into the 20th century—animage of remoteness, hardship, bleakness and isolation that was the province ofonly the most courageous of men. The image was one of a place removed fromeveryday reality, of a place with no apparent value to anyone.
B As we enter the 21st century, ourperception of Antarctica has changed. Although physically Antarctica is nocloser and probably no warmer, and to spend time there still demands adedication not seen in ordinary life, the continent and its surrounding oceanare increasingly seen to be an integral part of Planet Earth, and a keycomponent in the Earth System. Is this because the world seems a little smallerthese days, shrunk by TV and tourism, or is it because Antarctica really doesoccupy a central spot on Earth’s mantle? Scientific research during the pasthalf century has revealed—and continues to reveal—that Antarctica's great massand low temperature exert a major influence on climate and ocean circulation,factors which influence the lives of millions of people all over the globe.
C Antarctica was not always cold.The slow break-up of the super-continent Gondwana with the northward movementsof Africa, South America, India and Australia eventually created enough spacearound Antarctica for the development of an Antarctic Circumpolar Current(ACC), that flowed from west to east under the influence of the prevailingwesterly winds. Antarctica cooled, its vegetation perished, glaciation beganand the continent took on its present-day appearance. Today the ice thatoverlies the bedrock is up to 4km thick, and surface temperatures as low as-89.2deg C have been recorded. The icy blast that howls over the ice cap andout to sea—the so-called katabatic wind—can reach 300 km/hr, creating fearsomewind-chill effects,
D Out of this extreme environmentcome some powerful forces that reverberate around the world. The Earth’srotation, coupled to the generation of cells of low pressure off the Antarcticcoast, would allow Astronauts a view of Antarctica that is as beautiful as itis awesome. Spinning away to the northeast, the cells grow and deepen, whippingup the Southern Ocean into the mountainous seas so respected by mariners.Recent work is showing that the temperature of the ocean may be a betterpredictor of rainfall in Australia than is the pressure difference betweenDarwin and Tahiti—the Southern Oscillation Index. By receiving more accuratepredictions, graziers in northern Queensland are able to avoid overstocking inyears when rainfall will be poor. Not only does this limit their losses but itprevents serious pasture degradation that may take decades to repair. CSIRO isdeveloping this as a prototype forecasting system, but we can confidentlypredict that as we know more about the Antarctic and Southern Ocean we will beable to enhance and extend our predictive ability.
E The ocean’s surface temperatureresults from the interplay between deep-water temperature, air temperature andice. Each winter between 4 and 19 million square km of sea ice form, locking uphuge quantities of heat close to the continent. Only now can we start tounravel the influ-ence of sea ice on the weather that is experienced insouthern Australia. But in another way the extent of sea ice extends itsinfluence far beyond Antarctica. Antarctic krill—the small shrimp-likecrustaceans that are the staple diet for baleen whales, penguins, some seals,flighted sea birds and many fish—breed well in years when sea ice is extensiveand poorly when it is not. Many species of baleen whales and flighted sea birdsmigrate between the hemispheres and when the krill are less abundant they donot thrive.
F The circulatory system of theworld’s oceans is like a huge conveyor belt, moving water and dis-solvedminerals and nutrients from one hemisphere to the other, and from the ocean'sabyssal depths to the surface. The ACC is the longest current in the world, andhas the largest flow. Through it, the deep flows of the Atlantic, Indian andPacific Oceans are joined to form part of a single global thermohalinecirculation, During winter, the howling katabatics sometimes scour the ice offpatches of the sea's surface leaving large ice-locked lagoons, or ’polynyas'.Recent research has shown that as fresh sea ice forms, it is continuouslystripped away by the wind and may be blown up to 90km in a single day. Sinceonly fresh water freezes into ice, the water that remains becomes increasinglysalty and dense, sinking until it spills over the continental shelf. Cold watercarries more oxygen than warm water, so when it rises, well into the northernhemi-sphere, it reoxygenates and revitalises the ocean. The state of thenorthern oceans, and their biological productivity, owe much to what happens inthe Antarctic.
SECTION 2: QUESTIONS 14-26
Questions 14-18
Reading Passage 2 has sixparagraphs, A-F.
Which paragraph contains thefollowing information?
Write the correct letter, A-F, inboxes 14-18 onyour answer sheet:
14 ____________ Theexample of a research on building weather prediction for agriculture
15 ____________ Anexplanation of how Antarctic sea ice brings back oceans’ vitality
16 ____________ Thedescription of a food chain that influences animals’ living pattern
17 ____________ Thereference of an extreme temperature and a cold wind in Antarctica
18 ____________ Thereference of how Antarctica was once thought to be a forgotten andinsig-nificant continent
Questions 19-21
Match the natural phenomenonwith the correct determined factor.
Write the correct letter, A-F,in boxes 19-21 on your answer sheet.
Globally, Antarctica’s massivesize and 19 ____________ would influenceour climate.
20 ____________ circulated undercontributory force from wind blowing from the west.
The ocean temperature and indexbased on air pressure can help predict 21 ____________ in Australia.
A
Antarctic Circumpolar Current (ACC)
B
katabatic winds
C
rainfall
D
temperature
E
glaciers
F
pressure
Questions 22-26
Choose the correctletter, A, B, C or D.
Write the correct letter inboxes 22-26 on your answer sheet.
22In paragraph B, the author intends to
Ashow Antarctica has been a central topicof global warming discussion in Mass media.
Billustrate how its huge sea ice bringsfood to millions of lives in the world.
Cemphasise the significance of Antarcticato the global climate and ocean currents.
Dillustrate the geographical location ofAntarctica as the central spot on Earth.
23Why should Australian farmers keep an eyeon the Antarctic ocean temperature?
AIt can help farmers reduce their economicloss.
BIt allows for recovery of grassland lostto overgrazing.
CIt can help to prevent animals from dying
DIt enables astronauts to have a clear viewof the Antarctic continent.
24The decrease in the number of whales andseabirds is due to
Akiller whales’ activity around Antarctica.
Bthe correlation between sea birds’migration and the salinity level of the ocean.
Cthe lower productivity of food sourceresulting from less sea ice.
Dthe failure of seals to produce babies.
25What is the final effect of the katabaticwinds?
AIncreasing the moving speed of oceancurrent
BIncreasing the salt level near oceansurface
CBringing fresh ice into the oceans
DPiling up the mountainous ice caprespected by mariners
26What factor drives Antarctic water to movebeyond the continental shelf?
AA The increase of salt and density of thewater
BThe decrease of salt and density of thewater
CThe rising temperature due to globalwarming
DThe melting of fresh ice into the ocean
答案
雅思閱讀第040套P2-Antarctica – in from the cold?http://www.tuonindefu.com/?p=2332雅思閱讀第040套P2:Antarctica - in from the cold?
