Don'twashthosefossils!

StandardmuseumpracticecanwashawayDNA.

1.Washing,brushingandvarnishingfossils—allstandardconservationtreatmentsusedbymanyfossilhuntersandmuseumcuratorsalike—vastlyreducesthechancesofrecoveringancientDNA.

2.Instead,excavatorsshouldbehandlingatleastsomeoftheirbountywithgloves,andfreezingsamplesastheyarefound,dirtandall,concludesapaperintheProceedingsoftheNationalAcademyofSciencestoday.

3.AlthoughmanypalaeontologistsknowanecdotallythatthisisthebestwaytouptheoddsofextractinggoodDNA,Eva-MariaGeigloftheJacquesMonodInstituteinParis,France,andhercolleagueshavenowshownjusthowimportantconservationpracticescanbe.Thisinformation,theysay,needstobehammeredhomeamongthepeoplewhoareactuallyoutinthefielddiggingupbones.

4.Geiglandhercolleagueslookedat3,200-year-oldfossilbonesbelongingtoasingleindividualofanextinctcattlespecies,calledanaurochs.ThefossilsweredugupatasiteinFranceattwodifferenttimes—eitherin1947,andstoredinamuseumcollection,orin2004,andconservedinsterileconditionsat-20oC.

5.Theteam'sattemptstoextractDNAfromthe1947bonesallfailed.Thenewlyexcavatedfossils,however,allyieldedDNA.

6.Becausetheboneshadbeenburiedforthesameamountoftime,andinthesameconditions,theconservationmethodhadtobetoblamesaysGeigl."AsmuchDNAwasdegradedinthese57yearsasinthe3,200yearsbefore,"shesays.

Washin,washout

7.Becausemanypalaeontologistsbasetheirworkontheshapeoffossilsalone,theirmethodsofconservationarenotdesignedtopreserveDNA,Geiglexplains.

8.Thebiggestproblemishowtheyarecleaned.Fossilsareoftenwashedtogetheron-siteinalargebath,whichcanallowwater—andcontaminantsintheformofcontemporaryDNA—topermeateintotheporousbones."NotonlyistheauthenticDNAgettingwashedout,butcontaminationisgettingwashedin,"saysGeigl.

9.MostancientDNAspecialistsknowthisalready,saysHendrikPoinar,anevolutionarygeneticistatMcMasterUniversityinOntario,Canada.Butthatdoesn'tmeanthatbestpracticehasbecomewidespreadamongthosewhoactuallyfindthefossils.

10.GettingholdoffossilsthathavebeenpreservedwiththeirDNAinmindreliesoncloserelationshipsbetweenlab-basedgeneticistsandtheexcavators,sayspalaeogeneticistSvantePbooftheMaxPlanckInstituteforEvolutionaryAnthropologyinLeipzig,Germany.Andthatonlyoccursinexceptionalcases,hesays.

11.Pbo'steam,whichhasbeensequencingNeanderthalDNA,continuallyfacestheseproblems."WhenyouwanttostudyancienthumanandNeanderthalremains,there'sabigissueofcontaminationwithcontemporaryhumanDNA,"hesays.

12.Thisdoesn'tmeanthatallmuseumspecimensarefatallyflawed,notesPbo.TheNeanderthalfossilsthatwererecentlysequencedinhisownlab,forexample,hadbeenpartofamuseumcollectiontreatedinthetraditionalway.ButPboiskeentoseesamplesoffossilsfromeverymajorfindpreservedinlinewithGeigl'srecommendations—justincase.

Warmandwet

13.Geiglherselfbelievesthat,withcooperationbetweenbenchandfieldresearchers,preservingfossilsproperlycouldopenupavenuesofdiscoverythathavelongbeenassumedclosed.

14.Muchhumanculturaldevelopmenttookplaceintemperateregions.DNAdoesnotsurvivewellinwarmenvironmentsinthefirstplace,andcanvanishwhenfossilsarewashedandtreated.Forthisreason,Geiglsays,mostancientDNAstudieshavebeendoneonpermafrostsamples,suchasthewoollymammoth,oronremainsshelteredfromtheelementsincoldcaves—includingcavebearandNeanderthalfossils.

15.Betterconservationmethods,andafocusonfreshfossils,couldboostDNAextractionfrommoredelicatespecimens,saysGeigl.Andthatcouldshedmorelightonthestoryofhumanevolution.

(640wordsnature)

Glossary

Palaeontologists古生物学家

Aurochs欧洲野牛

Neanderthal(人类学)尼安德特人,旧石器时代的古人类。

Permafrost(地理)永冻层

Questions1-6

AnswerthefollowingquestionsbyusingNOMORETHANTHREEWORDSforeachanswer.

1.Howdidpeopletraditionallytreatfossils?

2.WhatsuggestionsdoGeiglandhercolleaguesgiveonwhatshouldbedonewhenfossilsarefound?

3.Whatproblemsmaybeposediffossilbonesarewashedon-site?NameONE.

4.WhatcharacteristicdofossilboneshavetomakethemsusceptibletobecontaminatedwithcontemporaryDNAwhentheyarewashed?

5.Whatcouldbebetterunderstoodwhenconservationtreatmentsareimproved?

6.Thepassagementionedseveralanimalspeciesstudiedbyresearchers.Howmanyofthemarementioned?

Questions7-11

Dothefollowingstatementsagreewiththeinformationgiveninthepassage?PleasewriteTRUEifthestatementagreeswiththewriterFALSEifthestatementdoesnotagreewiththewriterNOTGIVENifthereisnoinformationaboutthisinthepassage.

7.IntheirpaperpublishedintheProceedingsoftheNationalAcademyofSciences,GeiglandhercolleagueshaveshownwhatconservationpracticesshouldbefollowedtopreserveancientDNA.

8.ThefossilbonesthatGeiglandhercolleaguesstudiedareallfromthesameaurochs.

9.Geneticistsdon'thavetoworkonsite.

10.OnlynewlyexcavatedfossilbonesusingnewconservationmethodssuggestedbyGeiglandhercolleaguescontainancientDNA.

11.Paaboisstillworriedaboutthepotentialproblemscausedbytreatmentsoffossilsintraditionalway.

Questions12-13

CompletethefollowingthestatementsbychoosingletterA-Dforeachanswer.

12.“Thisinformation”inparagraph3indicates:

[A]ItiscriticaltofollowproperpracticesinpreservingancientDNA.

[B]ThebestwayofgettinggoodDNAistohandlefossilswithgloves.

[C]Fossilhuntersshouldwearhome-madehammerswhilediggingupbones.

[D]Manypalaeontologistsknowhowoneshoulddointreatingfossils.

13.ThestudyconductedbyGeiglandhercolleaguessuggests:

[A]thefactthatancientDNAcannotberecoveredfromfossilbonesexcavatedinthepast.

[B]thecorrelationbetweentheamountofburyingtimeandthatoftherecoveredDNA.

[C]thepaceatwhichDNAdegrades.

[D]thecorrelationbetweenconservationpracticesanddegradationofDNA.

查看答案
正确答案:

1.washing, brushing, varnishing 见第一段。

2.handling with gloves / freezing samples ( any one of the two ) 见第二段。

3.losing authentic DNA / being contaminated / contamination ( any one of the three) 见第八段“Not only is the authentic DNA getting washed out, but contamination is getting washed in”(答being contaminated或 contamination比较保险)

4.they are porous porous 的意思是多孔的。见第八段“...which can allow water — and contaminants in the form of contemporary DNA — to permeate into the porous bones.”

5.human evolution 见第十五段。其中“shed light on sth”的意思是使某事显得非常清楚,使人了解某事。

6.4 分别为第四段的“an extinct cattle species, called an aurochs”,即欧洲野牛,已经绝迹;第十一段“Neanderthal”, 是人类学用语,尼安德特人,旧石器时代的古人类;第十四段“woolly mammoth”和“cave bear”,其中mammoth是猛犸,一种古哺乳动物。

7.T 见第二段。

8.T 见第四段“Geigl and her colleagues looked at 3,200-year-old fossil bones belonging to a single individual of an extinct cattle species, called an aurochs.”即他们研究的骨化石是一头欧洲野牛身上的。

9.NG

10.F 见第十二段第一、二句话。

11.T 见第十二段末句“But P bo is keen to see samples of fossils from every major find preserved in line with Geigl's recommendations — just in case.”意即为保险起见,Paabo还是非常希望见到用Geigl建议的方法保存的化石样本。“just in case” 的意思是以防万一,就是Paabo对用传统保存处理的化石不放心的意思。

12.A 见第三段。This information就是前一句中“...just how important conservation practices can be”(to preserve good DNA)。“be hammered”之中hammer一词的意思是不断重复强调。

13.D 面信息。需要理解文章各处关于Geigl和她的同事所作的研究。

答案解析:

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In the earliest stages of man's development he had nomore need of money than animals have.He was content with very simple forms of shelter,made his own rough tools and weapons and could provide food and clothing for himself and his family from natural materials around him.As he became more civilized,however,he began to want better shelter,more efficient tools and weapons,and more comfortable and more lasting clothing than could be provided by his own neighborhood or by the work of his own unskilled hands.For these things he had to turn to the skilled people such as smiths,leather workers or carpenters.It was then that the question of payment arose.

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1.Exchange of goods became difficult because _________.

A man became more civilized

B smiths began to look after land or cattle in their spare time

C more and more goods which had no fixed exchange alues came to the marker

D farmers hadn't enough grain or meat to provide for

skilled workers

2.Money was not used until _______.

A paper was invented

B people practiced a simple process of exchange

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3.The best title for this passage is _____.

A What is money

B What are money's functions.

C The importance of money

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How a Frenchman is reviving McDonald’s in Europe

A. When Denis Hennequin took over as the European boss of McDonald’s in January 2004, the world’s biggest restaurant chain was showing signs of recovery in America and Australia, but sales in Europe were sluggish or declining. One exception was France, where Mr Hennequin had done a sterling job as head of the group’s French subsidiary to sell more Big Macs to his compatriots. His task was to replicate this success in all 41 of the European countries where anti-globalisers’ favourite enemy operates.

B. So far Mr Hennequin is doing well. Last year European sales increased by 5.8% and the number of customers by 3.4%, the best annual results in nearly 15 years. Europe accounted for 36% of the group’s profits and for 28% of its sales. December was an especially good month as customers took to seasonal menu offerings in France and Britain, and to a promotion in Germany based on the game of Monopoly.

C. Mr Hennequin’s recipe for revival is to be more open about his company’s operations, to be “locally relevant”, and to improve the experience of visiting his 6,400 restaurants. McDonald’s is blamed for making people fat, exploiting workers, treating animals cruelly, polluting the environment and simply for being American. Mr Hennequin says he wants to engage in a dialogue with the public to address these concerns.

D. He introduced “open door” visitor days in each country which became hugely popular. In Poland alone some 50,000 visitors came to McDonald’s through the visitors’ programme last year. The Nutrition Information Initiative, launched last year, put detailed labels on McDonald’s packaging with data on calories, protein, fat, carbohydrates and salt content. The details are also printed on tray-liners.

E. Mr Hennequin also wants people to know that “McJobs”, the low-paid menial jobs at McDonald’s restaurants, are much better than people think. But some of his efforts have backfired: last year he sparked a controversy with the introduction of a “McPassport” that allows McDonald’s employees to work anywhere in the European Union. Politicians accused the firm of a ploy to make cheap labour from eastern Europe more easily available to McDonald’s managers across the continent.

F. To stay in touch with local needs and preferences, McDonald’s employs local bosses as much as possible. A Russian is running McDonald’s in Russia, though a Serb is in charge of Germany. The group buys mainly from local suppliers. Four-fifths of its supplies in France come from local farmers, for example. (Some of the French farmers who campaigned against the company in the late 1990s subsequently discovered that it was, in fact, buying their produce.) And it hires celebrities such as Heidi Klum, a German model, as local brand ambassadors.

G. In his previous job Mr Hennequin established a “design studio” in France to spruce up his company’s drab restaurants and adapt the interior to local tastes. The studio is now masterminding improvements everywhere in Europe. He also set up a “food studio”, where cooks devise new recipes in response to local trends.

H. Given France’s reputation as the most anti-American country in Europe, it seems odd that McDonald’s revival in Europe is being led by a Frenchman, using ideas cooked up in the French market. But France is in fact the company’s most profitable market after America. The market where McDonald’s is weakest in Europe is not France, but Britain.

I. “Fixing Britain should be his priority,” says David Palmer, a restaurant analyst at UBS. Almost two-thirds of the 1,214 McDonald’s restaurants in Britain are company-owned, compared with 40% in Europe and 15% in America. The company suffers from the volatility of sales at its own restaurants, but can rely on steady income from franchisees. So it should sell as many underperforming outlets as possible, says Mr Palmer.

J. M.Mark Wiltamuth, an analyst at Morgan Stanley, estimates that European company-owned restaurants’ margins will increase slightly to 16.4% in 2007. This is still less than in the late 1990s and below America’s 18-19% today. But it is much better than before Mr Hennequin’s reign. He is already being tipped as the first European candidate for the group’s top job in Illinois. Nobody would call that a McJob.

Notes to Reading Passage 1

1.sterling高质量的

e.g. He has many sterling qualities. 他身上有许多优秀的品质。

2. menial 不体面的, 乏味的(工作、职业)

3. spruce up打扮整齐、漂亮、装饰

4. mastermind指挥、谋划(一个计划或活动)

e.g. The police know who masterminded the robbery.警察知道是谁策划了那次抢劫。

5. underperform表现不佳表现出低于标准的工作水平、企业出现亏本

Questions 1-6

Do the following statements reflect the claims of the writer in Reading Passage 1?

Write your answer in Boxes 1-6 on your answer sheet.

TRUE if the statement reflects the claims of the writer

FALSE if the statement contradicts the claims of the writer

NOT GIVEN if it is impossible to say what the writer thinks about this

1. McDonald was showing the sign of recovery in all European countries except France after Denis Hennequin took office as the boss of Euro-markets.

2. Starting from last year, detailed labels are put on McDonald’s packaging and detailed information is also printed on tray-liners.

3. France is said to be the most anti-American country in Europe, but the ideas of the “open door” visiting days and “McPassport” are invented in the French market.

4. Britain possesses the weakest McDonald market among European countries and approximately 1214 McDonald’s restaurants are company-owned.

5. According to David Palmer, a restaurant analyst at UBS, David Hennequin should treat the problem about McDonald in Britain as the most important thing.

6. David Palmer suggested that the management of McDonalod in Italy should sell as many its outlets which lose money in business as possible for revival.

Questions 7-10

Choose the appropriate letters A-D and write them in boxes 7-10 on your answe sheet.

7. The word “sterling” in line 3 of Paragraph A means__________.

A. difficult

B. menial

C. terrible

D. excellent

8. Which of the following statements on the accusation of MacDonald is NOT TRUE?

A. It tends to make people fat.

B. Its operations are very vague.

C. It tends to exploit workers.

D. It tends to treat animals cruelly.

9. Which of the following measures taken by Denis Hennequin produced undesired result?

A. “Food Studio” scheme.

B. “Open Door” visitor days.

C. The “McPassport” scheme.

D. The Nutrition Information Initiative.

10. What did Denis Hennequin do so as to respond to local trends?

A. set up a “Food Studio” .

B. established a “Design Studio”.

C. hired celebrities as local brand ambassadors.

D. employed local bosses as much as possible.

Questions 11-14

Complete each of the following statements (Questions 11-14) with words or number taken from Reading Passage 1.

Write NO MORE THAN THREE WORDS for each answer.

Write your answers in boxes 11-14 on your answer sheet.

11. After January 2004, McDonald was making improvement following a period of slump in America and Australia, but sales in Europe were ………………………….

12. Business of McDonald in France and Britain was particularly good in December since customers took to ……………………………..

13. Compared with other countries, France is McDonald’s ………………………. next to America.

14. ……………………. of McDonald’s restaurants in America are companied–owned and the figure is much lower than that in Britain.

Selling Digital Music without Copy-protection Makes Sense

A. It was uncharacteristically low-key for the industry’s greatest showman. But the essay published this week by Steve Jobs, the boss of Apple, on his firm’s website under the unassuming title “Thoughts on Music” has nonetheless provoked a vigorous debate about the future of digital music, which Apple dominates with its iPod music-player and iTunes music-store. At issue is “digital rights management” (DRM)—the technology guarding downloaded music against theft. Since there is no common standard for DRM, it also has the side-effect that songs purchased for one type of music-player may not work on another. Apple’s DRM system, called FairPlay, is the most widespread. So it came as a surprise when Mr. Jobs called for DRM for digital music to be abolished.

B. This is a change of tack for Apple. It has come under fire from European regulators who claim that its refusal to license FairPlay to other firms has “locked in” customers. Since music from the iTunes store cannot be played on non-iPod music-players (at least not without a lot of fiddling), any iTunes buyer will be deterred from switching to a device made by a rival firm, such as Sony or Microsoft. When French lawmakers drafted a bill last year compelling Apple to open up FairPlay to rivals, the company warned of “state-sponsored piracy”. Only DRM, it implied, could keep the pirates at bay.

C. This week Mr. Jobs gave another explanation for his former defence of DRM: the record companies made him do it. They would make their music available to the iTunes store only if Apple agreed to protect it using DRM. They can still withdraw their catalogues if the DRM system is compromised. Apple cannot license FairPlay to others, says Mr Jobs, because it would depend on them to produce security fixes promptly. All DRM does is restrict consumer choice and provide a barrier to entry, says Mr Jobs; without it there would be far more stores and players, and far more innovation. So, he suggests, why not do away with DRM and sell music unprotected? “This is clearly the best alternative for consumers,” he declares, “and Apple would embrace it in a heartbeat.”

D. Why the sudden change of heart? Mr Jobs seems chiefly concerned with getting Europe’s regulators off his back. Rather than complaining to Apple about its use of DRM, he suggests, “those unhappy with the current situation should redirect their energies towards persuading the music companies to sell their music DRM-free.” Two and a half of the four big record companies, he helpfully points out, are European-owned. Mr Jobs also hopes to paint himself as a consumer champion. Apple resents accusations that it has become the Microsoft of digital music.

E. Apple can afford to embrace open competition in music players and online stores. Consumers would gravitate to the best player and the best store, and at the moment that still means Apple’s. Mr Jobs is evidently unfazed by rivals to the iPod. Since only 3% of the music in a typical iTunes library is protected, most of it can already be used on other players today, he notes. (And even the protected tracks can be burned onto a CD and then re-ripped.) So Apple’s dominance evidently depends far more on branding and ease of use than DRM-related “lock in”.

F. The music giants are trying DRM-free downloads. Lots of smaller labels already sell music that way. Having seen which way the wind is blowing, Mr Jobs now wants to be seen not as DRM’s defender, but as a consumer champion who helped in its downfall. Wouldn’t it lead to a surge in piracy? No, because most music is still sold unprotected on CDs, people wishing to steal music already can do so. Indeed, scrapping DRM would probably increase online-music sales by reducing confusion and incompatibility. With the leading online store, Apple would benefit most. Mr Jobs’s argument, in short, is transparently self-serving. It also happens to be right.

Notes to Reading Passage 1

1. low-key:

抑制的,受约束的,屈服的

2. showman:

开展览会的人, 出风头的人物

3. unassuming:

谦逊的, 不夸耀的, 不装腔作势的

4. iPod:

(苹果公司出产的)音乐播放器

5. iTunes store:

(苹果公司出产的)在线音乐商店

6. get off person’s back:

不再找某人的麻烦,摆脱某人的纠缠

7. gravitate:

受吸引,倾向于

8. unfazed:

不再担忧,不被打扰

Questions 1-7

Do the following statemets reflect the claims of the writer in Reading Passage 1?

Write your answer in Boxes 1-7 on your answer sheet.

TRUE if the statement reflets the claims of the writer

FALSE if the statement contradicts the claims of the writer

NOT GIVEN if it is impossbile to say what the writer thinks about this

1. Apple enjoys a controlling position in digital music market with its iPod music-player and iTunes music-store.

2. DRM is a government decree issued with a purpose to protect downloaded music from theft by consumers.

3. Lack of standardization in DRM makes songs bought for one kind of music player may not function on another.

4. Apple has been criticized by European regulators since it has refused to grant a license FairPlay to other firms.

5. All music can be easily played on non-iPod music devices from Sony or Microsoft without too much fiddling.

6. Apple depends far more on DRM rather than branding for its dominance of the digital music devices.

7. If DRM was cancelled, Sony would certainly dominate the international digital music market.

Questions 8-10

Choose the appropriate letters A-D and write them in boxes 8-10 on your answe sheet.

8. Which of the following statements about Mr. Jobs’ idea of DRM is NOT TRUE?

A. DRM places restrictions on consumer’ choice of digital music products available.

B. DRM comples iTunes buyers to switch to a device made by Sony or Microsoft.

C. DRM constitutes a barrier for potential consumers to enter digital music markets.

D. DRM hinders development of more stores and players and technical innovation.

9. The word “unfazed” in line 3 of paragraph E, means___________.

A. refused

B. welcomed

C. not bothered

D. not well received

10. Which of the following statements is TRUE if DRM was scapped?

A. Sony would gain the most profit.

B. More customers would be “locked in”.

C. A sudden increase in piracy would occur.

D. Online-music sales would probably decrease.

Questions 11-14

Complete the notes below.

Choose NO MORE THAN THREE WORDS from Reading Passage 1 for each answer.

Write your answers in boxes 11-14 on your answer sheet.

Mr. Steve Jobs, the boss of Apple, explains the reason why he used to defend DRM, saying that the company was forced to do so: the record companies would make their music accessible to …11...only if they agreed to protect it using DRM; they can still…12…if the DRM system is compromised. He also provides the reason why Apple did not license FairPlay to others: the company relies on them to …13….But now he changes his mind with a possible expectation that Europe’s regulators would not trouble him any more in the future. He proposes that those who are unsatisfactory with the current situation in digital music market should …14… towards persuade the music companies to sell their music DRM-free.

-----Whataboutthepenyouboughtyesterday?

-----It____________well.Ilikeitverymuch.

A、waswritten
B、iswritten
C、wrote
D、writes

1There'sadimmerswitchinsidethesunthatcausesitsbrightnesstoriseandfallontimescalesofaround100,000years-exactlythesameperiodasbetweeniceagesonEarth.Sosaysaphysicistwhohascreatedacomputermodelofourstar'score.

2RobertEhrlichofGeorgeMasonUniversityinFairfax,Virginia,modelledtheeffectoftemperaturefluctuationsinthesun'sinterior.Accordingtothestandardview,thetemperatureofthesun'scoreisheldconstantbytheopposingpressuresofgravityandnuclearfusion.However,Ehrlichbelievedthatslightvariationsshouldbepossible.

3HetookashisstartingpointtheworkofAttilaGrandpierreoftheKonkolyObservatoryoftheHungarianAcademyofSciences.In2005,Grandpierreandacollaborator,Gáborágoston,calculatedthatmagneticfieldsinthesun'scorecouldproducesmallinstabilitiesinthesolarplasma.Theseinstabilitieswouldinducelocalisedoscillationsintemperature.

4Ehrlich'smodelshowsthatwhilstmostoftheseoscillationscanceleachotherout,somereinforceoneanotherandbecomelong-livedtemperaturevariations.Thefavouredfrequenciesallowthesun'scoretemperaturetooscillatearounditsaveragetemperatureof13.6millionkelvinincycleslastingeither100,000or41,000years.Ehrlichsaysthatrandominteractionswithinthesun'smagneticfieldcouldflipthefluctuationsfromonecyclelengthtotheother.

5ThesetwotimescalesareinstantlyrecognisabletoanyonefamiliarwithEarth'siceages:forthepastmillionyears,iceageshaveoccurredroughlyevery100,000years.Beforethat,theyoccurredroughlyevery41,000years.

6MostscientistsbelievethattheiceagesaretheresultofsubtlechangesinEarth'sorbit,knownastheMilankovitchcycles.OnesuchcycledescribesthewayEarth'sorbitgraduallychangesshapefromacircletoaslightellipseandbackagainroughlyevery100,000years.ThetheorysaysthisalterstheamountofsolarradiationthatEarthreceives,triggeringtheiceages.However,apersistentproblemwiththistheoryhasbeenitsinabilitytoexplainwhytheiceageschangedfrequencyamillionyearsago.

7"InMilankovitch,thereiscertainlynogoodideawhythefrequencyshouldchangefromonetoanother,"saysNeilEdwards,aclimatologistattheOpenUniversityinMiltonKeynes,UK.NoristhetransitionproblemtheonlyonetheMilankovitchtheoryfaces.EhrlichandothercriticsclaimthatthetemperaturevariationscausedbyMilankovitchcyclesaresimplynotbigenoughtodriveiceages.

8However,EdwardsbelievesthesmallchangesinsolarheatingproducedbyMilankovitchcyclesarethenamplifiedbyfeedbackmechanismsonEarth.Forexample,ifseaicebeginstoformbecauseofaslightcooling,carbondioxidethatwouldotherwisehavefounditswayintotheatmosphereaspartofthecarboncycleislockedintotheice.ThatweakensthegreenhouseeffectandEarthgrowsevencolder.

9AccordingtoEdwards,thereisnolackofsuchmechanisms."Ifyouaddtheireffectstogether,thereismorethanenoughfeedbacktomakeMilankovitchwork,"hesays."Theproblemnowisidentifyingwhichmechanismsareatwork."ThisiswhyscientistslikeEdwardsarenotyetreadytogiveuponthecurrenttheory."Milankovitchcyclesgiveusiceagesroughlywhenweobservethemtohappen.Wecancalculatewhereweareinthecycleandcompareitwithobservation,"hesays."Ican'tseeanywayoftesting[Ehrlich's]ideatoseewhereweareinthetemperatureoscillation."

10Ehrlichconcedesthis."Ifthereisawaytotestthistheoryonthesun,Ican'tthinkofonethatispractical,"hesays.That'sbecausevariationover41,000to100,000yearsistoogradualtobeobserved.However,theremaybeawaytotestitinotherstars:reddwarfs.Theircoresaremuchsmallerthanthatofthesun,andsoEhrlichbelievesthattheoscillationperiodscouldbeshortenoughtobeobserved.Hehasyettocalculatethepreciseperiodortheextentofvariationinbrightnesstobeexpected.

11NigelWeiss,asolarphysicistattheUniversityofCambridge,isfarfromconvinced.HedescribesEhrlich'sclaimsas"utterlyimplausible".EhrlichcountersthatWeiss'sopinionisbasedonthestandardsolarmodel,whichfailstotakeintoaccountthemagneticinstabilitiesthatcausethetemperaturefluctuations.

Questions1-4

CompleteeachofthefollowingstatementswithOneorTwonamesofthescientistsfromtheboxbelow.

WritetheappropriatelettersA-Einboxes1-4onyouranswersheet.

A.AttilaGrandpierre

B.Gáborágoston

C.NeilEdwards

D.NigelWeiss

E.RobertEhrlich

1....claimsthereadimmerswitchinsidethesunthatcausesitsbrightnesstoriseandfallinperiodsaslongasthosebetweeniceagesonEarth.

2....calculatedthattheinternalsolarmagneticfieldscouldproduceinstabilitiesinthesolarplasma.

3....holdsthatMilankovitchcyclescaninducechangesinsolarheatingonEarthandthechangesareamplifiedonEarth.

4....doesn'tbelieveinEhrlich'sviewpointsatall.

Questions5-9

Dothefollowingstatementsagreewiththeinformationgiveninthereadingpassage?

Inboxes5-9onyouranswersheetwrite

TRUEifthestatementistrueaccordingtothepassage

FALSEifthestatementisfalseaccordingtothepassage

NOTGIVENiftheinformationisnotgiveninthepassage

5.Theiceageschangedfrequencyfrom100,000to41,000yearsamillionyearsago.

6.ThesoleproblemthattheMilankovitchtheorycannotsolveistoexplainwhytheiceagefrequencyshouldshiftfromonetoanother.

7.Carbondioxidecanbelockedartificiallyintoseaicetoeliminatethegreenhouseeffect.

8.SomescientistsarenotreadytogiveuptheMilankovitchtheorythoughtheyhaven'tfiguredoutwhichmechanismsamplifythechangesinsolarheating.

9.BothEdwardsandEhrlichbelievethatthereisnopracticalwaytotestwhenthesolartemperatureoscillationbeginsandwhenends.

Questions10-14

Completethenotesbelow.

ChooseonesuitablewordfromtheReadingPassageaboveforeachanswer.

Writeyouranswersinboxes10-14onyouranswersheet.

Thestandardviewassumesthattheopposingpressuresofgravityandnuclearfusionsholdthetemperature...10...inthesun'sinterior,buttheslightchangesintheearth's...11...alterthetemperatureontheearthandcauseiceagesevery100,000years.ABritishscientist,however,challengesthisviewbyclaimingthattheinternalsolarmagnetic...12...caninducethetemperatureoscillationsinthesun'sinterior.Thesun'scoretemperatureoscillatesarounditsaveragetemperaturein...13...lastingeither100,000or41,000years.Andthe...14...interactionswithinthesun'smagneticfieldcouldflipthefluctuationsfromonecyclelengthtotheother,whichexplainswhytheiceageschangedfrequencyamillionyearsago.

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