1 There's a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star's core.
2 Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun's interior. According to the standard view, the temperature of the sun's core is held constant by the opposing pressures of gravity and nuclear fusion. However, Ehrlich believed that slight variations should be possible.
3 He took as his starting point the work of Attila Grandpierre of the Konkoly Observatory of the Hungarian Academy of Sciences. In 2005, Grandpierre and a collaborator, Gábor ágoston, calculated that magnetic fields in the sun's core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.
4 Ehrlich's model shows that whilst most of these oscillations cancel each other out, some reinforce one another and become long-lived temperature variations. The favoured frequencies allow the sun's core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years. Ehrlich says that random interactions within the sun's magnetic field could flip the fluctuations from one cycle length to the other.
5 These two timescales are instantly recognisable to anyone familiar with Earth's ice ages: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
6 Most scientists believe that the ice ages are the result of subtle changes in Earth's orbit, known as the Milankovitch cycles. One such cycle describes the way Earth's orbit gradually changes shape from a circle to a slight ellipse and back again roughly every 100,000 years. The theory says this alters the amount of solar radiation that Earth receives, triggering the ice ages. However, a persistent problem with this theory has been its inability to explain why the ice ages changed frequency a million years ago.
7 "In Milankovitch, there is certainly no good idea why the frequency should change from one to another," says Neil Edwards, a climatologist at the Open University in Milton Keynes, UK. Nor is the transition problem the only one the Milankovitch theory faces. Ehrlich and other critics claim that the temperature variations caused by Milankovitch cycles are simply not big enough to drive ice ages.
8 However, Edwards believes the small changes in solar heating produced by Milankovitch cycles are then amplified by feedback mechanisms on Earth. For example, if sea ice begins to form because of a slight cooling, carbon dioxide that would otherwise have found its way into the atmosphere as part of the carbon cycle is locked into the ice. That weakens the greenhouse effect and Earth grows even colder.
9 According to Edwards, there is no lack of such mechanisms. "If you add their effects together, there is more than enough feedback to make Milankovitch work," he says. "The problem now is identifying which mechanisms are at work." This is why scientists like Edwards are not yet ready to give up on the current theory. "Milankovitch cycles give us ice ages roughly when we observe them to happen. We can calculate where we are in the cycle and compare it with observation," he says. "I can't see any way of testing [Ehrlich's] idea to see where we are in the temperature oscillation."
10 Ehrlich concedes this. "If there is a way to test this theory on the sun, I can't think of one that is practical," he says. That's because variation over 41,000 to 100,000 years is too gradual to be observed. However, there may be a way to test it in other stars: red dwarfs. Their cores are much smaller than that of the sun, and so Ehrlich believes that the oscillation periods could be short enough to be observed. He has yet to calculate the precise period or the extent of variation in brightness to be expected.
11 Nigel Weiss, a solar physicist at the University of Cambridge, is far from convinced. He describes Ehrlich's claims as "utterly implausible". Ehrlich counters that Weiss's opinion is based on the standard solar model, which fails to take into account the magnetic instabilities that cause the temperature fluctuations.
Questions 1-4
Complete each of the following statements with One or Two names of the scientists from the box below.
Write the appropriate letters A-E in boxes 1-4 on your answer sheet.
A. Attila Grandpierre
B. Gábor ágoston
C. Neil Edwards
D. Nigel Weiss
E. Robert Ehrlich
1. ...claims there a dimmer switch inside the sun that causes its brightness to rise and fall in periods as long as those between ice ages on Earth.
2. ...calculated that the internal solar magnetic fields could produce instabilities in the solar plasma.
3. ...holds that Milankovitch cycles can induce changes in solar heating on Earth and the changes are amplified on Earth.
4. ...doesn't believe in Ehrlich's viewpoints at all.
Questions 5-9
Do the following statements agree with the information given in the reading passage?
In boxes 5-9 on your answer sheet write
TRUE if the statement is true according to the passage
FALSE if the statement is false according to the passage
NOT GIVEN if the information is not given in the passage
5. The ice ages changed frequency from 100,000 to 41,000 years a million years ago.
6. The sole problem that the Milankovitch theory can not solve is to explain why the ice age frequency should shift from one to another.
7. Carbon dioxide can be locked artificially into sea ice to eliminate the greenhouse effect.
8. Some scientists are not ready to give up the Milankovitch theory though they haven't figured out which mechanisms amplify the changes in solar heating.
9. Both Edwards and Ehrlich believe that there is no practical way to test when the solar temperature oscillation begins and when ends.
Questions 10-14
Complete the notes below.
Choose one suitable word from the Reading Passage above for each answer.
Write your answers in boxes 10-14 on your answer sheet.
The standard view assumes that the opposing pressures of gravity and nuclear fusions hold the temperature ...10...in the sun's interior, but the slight changes in the earth's ...11... alter the temperature on the earth and cause ice ages every 100,000 years. A British scientist, however, challenges this view by claiming that the internal solar magnetic ...12... can induce the temperature oscillations in the sun's interior. The sun's core temperature oscillates around its average temperature in ...13... lasting either 100,000 or 41,000 years. And the ...14... interactions within the sun's magnetic field could flip the fluctuations from one cycle length to the other, which explains why the ice ages changed frequency a million years ago.
1. E
See the sentences in paragraph 1(There's a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star's core.) and para.2 (Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun's interior.)
2. A B
See para.3: Grandpierre and a collaborator, Gábor ágoston, calculated that magnetic fields in the sun's core could produce small instabilities in the solar plasma.
3. C
See para.8: Edwards believes the small changes in solar heating produced by Milankovitch cycles are then amplified by feedback mechanisms on Earth.
4. D
See para.11: Nigel Weiss, a solar physicist at the University of Cambridge, is far from convinced. He describes Ehrlich's claims as "utterly implausible".
5. False
See para.5: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
6. False
See para.7: "In Milankovitch, there is certainly no good idea why the frequency should change from one to another," ... Nor is the transition problem the only one the Milankovitch theory faces.
7. Not Given
See para.8: if sea ice begins to form because of a slight cooling, carbon dioxide?is locked into the ice. That weakens the greenhouse effect. (The passage doesn抰 mention anything about locking Co2 into ice artificially.)
8. True
See para.9: there is no lack of such mechanisms. "If you add their effects together, there is more than enough feedback to make Milankovitch work,"?"The problem now is identifying which mechanisms are at work." This is why scientists like Edwards are not yet ready to give up on the current theory.
9. True
See the sentences in para.9 (According to Edwards, he says. "I can't see any way of testing [Ehrlich's] idea to see where we are in the temperature oscillation.") and para.10 (Ehrlich concedes this. "If there is a way to test this theory on the sun, I can't think of one that is practical).
10. constant
See para.2: According to the standard view, the temperature of the sun's core is held constant by the opposing pressures of gravity and nuclear fusion.
11. orbit
See para.6: Most scientists believe that the ice ages are the result of subtle changes in Earth's orbit, Earth's orbit gradually changes shape from a circle to a slight ellipse and back again roughly every 100,000 years.
12. instabilities
See para.3: magnetic fields in the sun's core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.
13. cycles
See para.4: …allow the sun's core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years.
14. random
See para.4: Ehrlich says that random interactions within the sun's magnetic field could flip the fluctuations from one cycle length to the other.
暂无解析
-----AheavysnowhitmostofthepartsofChinainJanuary,2008.
-----____________terriblenews!
Felicity Lawrence
Thursday December 28, 2006
The Guardian
1. Consumers are to be presented with two rival new year advertising campaigns as the Food Standards Agency goes public in its battle with the industry over the labelling of unhealthy foods.
2. The Guardian has learned that the FSA will launch a series of 10-second television adverts in January telling shoppers how to follow a red, amber and green traffic light labelling system on the front of food packs, which is designed to tackle Britain’s obesity epidemic.
3. The campaign is a direct response to a concerted attempt by leading food manufacturers and retailers, including Kellogg’s and Tesco, to derail the system. The industry fears that traffic lights would demonise entire categories of foods and could seriously damage the market for those that are fatty, salty or high in sugar.
4. The UK market for breakfast cereals is worth ￡1.27bn a year and the manufacturers fear it will be severely dented if red light labels are put on packaging drawing attention to the fact that the majority are high in salt and/or sugar.
5. The industry is planning a major marketing campaign for a competing labelling system which avoids colour-coding in favour of information about the percentage of "guideline daily amounts" (GDAs) of fat, salt and sugar contained in their products.
6. The battle for the nation’s diet comes as new rules on television advertising come into force in January which will bar adverts for unhealthy foods from commercial breaks during programmes aimed at children. Sources at the TV regulators are braced for a legal challenge from the industry and have described the lobbying efforts to block any new ad ban or colour-coded labelling as "the most ferocious we’ve ever experienced".
7. Ofcom’s chief executive, Ed Richards, said: "We are prepared to face up to any legal action from the industry, but we very much hope it will not be necessary." The FSA said it was expecting an onslaught from the industry in January. Senior FSA officials said the manufacturers’ efforts to undermine its proposals on labelling could threaten the agency’s credibility.
8. Terrence Collis, FSA director of communications, dismissed claims that the proposals were not based on science. "We have some of the most respected scientists in Europe, both within the FSA and in our independent advisory committees. It is unjustified and nonsensical to attack the FSA’s scientific reputation and to try to undermine its credibility."
9. The FSA is understood to have briefed its ad agency, United, before Christmas, and will aim to air ads that are "non-confrontational, humorous and factual" as a counterweight to industry’s efforts about the same time. The agency, however, will have a tiny fraction of the budget available to the industry.
10. Gavin Neath, chairman of Unilever UK and president of the Food and Drink Federation, has said that the industry has made enormous progress but could not accept red "stop" signs on its food.
11. Alastair Sykes, chief executive of Nestlé UK, said that under the FSA proposals all his company’s confectionery and most of its cereals would score a red. "Are we saying people shouldn’t eat confectionery? We’re driven by consumers and what they want, and much of what we do has been to make our products healthier," he said.
12. Chris Wermann, director of communications at Kellogg’s, said: "In principle we could never accept traffic light labelling."
13. The rival labelling scheme introduced by Kellogg’s, Danone, Unilever, Nestlé, Kraft and Tesco and now favoured by 21 manufacturers, uses an industry-devised system based on identifying GDAs of key nutrients. Tesco says it has tested both traffic lights and GDA labels in its stores and that the latter increased sales of healthier foods.
14. But the FSA said it could not live with this GDA system alone because it was "not scientific" or easy for shoppers to understand at a glance.
Questions 1-6
Answer the questions below using NO MORE THAN THREE WORDS from the passage for each answer.
1. When will instructions be given on reading the color-coded labels?
2. Where can customers find the red light labels?
3. What problem is the FSA trying to handle with the labeling system?
4. Which product sells well but may not be healthy?
5. What information, according to the manufacturers, can be labeled on products?
6. What can not be advertised during children’s programmes?
Questions 7-13
Use the information in the text to match the people (listed A-E) with the opinions (listed 7-13) below. Write the appropriate letter (A-E) for questions 1-7.
NB You may use any letter more than once.
A Ed Richard
B Terrence Collis
C Gavin Neath
D Alastair Sykes
E Chris Wermann
7. Generally we will not agree to use the red light labels.
8. It is unreasonable to doubt if FSA is trustworthy.
9. We are trying to meet our consumers’ needs.
10. The food industry has been improving greatly.
11. The color-coded labeling system is scientific.
12. Our products will be labeled unhealthy by the FSA.
13. We are ready to confront the manufacturers.
-----Didyounoticehimcomein?
-----No.I________afootballgame.
SellingDigitalMusicwithoutCopy-protectionMakesSense
A. Itwasuncharacteristicallylow-keyfortheindustry’sgreatestshowman.ButtheessaypublishedthisweekbySteveJobs,thebossofApple,onhisfirm’swebsiteundertheunassumingtitle“ThoughtsonMusic”hasnonethelessprovokedavigorousdebateaboutthefutureofdigitalmusic,whichAppledominateswithitsiPodmusic-playerandiTunesmusic-store.Atissueis“digitalrightsmanagement”(DRM)—thetechnologyguardingdownloadedmusicagainsttheft.SincethereisnocommonstandardforDRM,italsohastheside-effectthatsongspurchasedforonetypeofmusic-playermaynotworkonanother.Apple’sDRMsystem,calledFairPlay,isthemostwidespread.SoitcameasasurprisewhenMr.JobscalledforDRMfordigitalmusictobeabolished.
B. ThisisachangeoftackforApple.IthascomeunderfirefromEuropeanregulatorswhoclaimthatitsrefusaltolicenseFairPlaytootherfirmshas“lockedin”customers.SincemusicfromtheiTunesstorecannotbeplayedonnon-iPodmusic-players(atleastnotwithoutalotoffiddling),anyiTunesbuyerwillbedeterredfromswitchingtoadevicemadebyarivalfirm,suchasSonyorMicrosoft.WhenFrenchlawmakersdraftedabilllastyearcompellingAppletoopenupFairPlaytorivals,thecompanywarnedof“state-sponsoredpiracy”.OnlyDRM,itimplied,couldkeepthepiratesatbay.
C. ThisweekMr.JobsgaveanotherexplanationforhisformerdefenceofDRM:therecordcompaniesmadehimdoit.TheywouldmaketheirmusicavailabletotheiTunesstoreonlyifAppleagreedtoprotectitusingDRM.TheycanstillwithdrawtheircataloguesiftheDRMsystemiscompromised.ApplecannotlicenseFairPlaytoothers,saysMrJobs,becauseitwoulddependonthemtoproducesecurityfixespromptly.AllDRMdoesisrestrictconsumerchoiceandprovideabarriertoentry,saysMrJobs;withoutittherewouldbefarmorestoresandplayers,andfarmoreinnovation.So,hesuggests,whynotdoawaywithDRMandsellmusicunprotected?“Thisisclearlythebestalternativeforconsumers,”hedeclares,“andApplewouldembraceitinaheartbeat.”
D. Whythesuddenchangeofheart?MrJobsseemschieflyconcernedwithgettingEurope’sregulatorsoffhisback.RatherthancomplainingtoAppleaboutitsuseofDRM,hesuggests,“thoseunhappywiththecurrentsituationshouldredirecttheirenergiestowardspersuadingthemusiccompaniestoselltheirmusicDRM-free.”Twoandahalfofthefourbigrecordcompanies,hehelpfullypointsout,areEuropean-owned.MrJobsalsohopestopainthimselfasaconsumerchampion.AppleresentsaccusationsthatithasbecometheMicrosoftofdigitalmusic.
E. Applecanaffordtoembraceopencompetitioninmusicplayersandonlinestores.Consumerswouldgravitatetothebestplayerandthebeststore,andatthemomentthatstillmeansApple’s.MrJobsisevidentlyunfazedbyrivalstotheiPod.Sinceonly3%ofthemusicinatypicaliTuneslibraryisprotected,mostofitcanalreadybeusedonotherplayerstoday,henotes.(AndeventheprotectedtrackscanbeburnedontoaCDandthenre-ripped.)SoApple’sdominanceevidentlydependsfarmoreonbrandingandeaseofusethanDRM-related“lockin”.
F. ThemusicgiantsaretryingDRM-freedownloads.Lotsofsmallerlabelsalreadysellmusicthatway.Havingseenwhichwaythewindisblowing,MrJobsnowwantstobeseennotasDRM’sdefender,butasaconsumerchampionwhohelpedinitsdownfall.Wouldn’titleadtoasurgeinpiracy?No,becausemostmusicisstillsoldunprotectedonCDs,peoplewishingtostealmusicalreadycandoso.Indeed,scrappingDRMwouldprobablyincreaseonline-musicsalesbyreducingconfusionandincompatibility.Withtheleadingonlinestore,Applewouldbenefitmost.MrJobs’sargument,inshort,istransparentlyself-serving.Italsohappenstoberight.
NotestoReadingPassage1
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.iTunesstore：
(苹果公司出产的)在线音乐商店
6.getoffperson’sback:
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
Questions1-7
DothefollowingstatemetsreflecttheclaimsofthewriterinReadingPassage1?
WriteyouranswerinBoxes1-7onyouranswersheet.
TRUEifthestatementrefletstheclaimsofthewriter
FALSEifthestatementcontradictstheclaimsofthewriter
NOTGIVENifitisimpossbiletosaywhatthewriterthinksaboutthis
1.AppleenjoysacontrollingpositionindigitalmusicmarketwithitsiPodmusic-playerandiTunesmusic-store.
2.DRMisagovernmentdecreeissuedwithapurposetoprotectdownloadedmusicfromtheftbyconsumers.
3.LackofstandardizationinDRMmakessongsboughtforonekindofmusicplayermaynotfunctiononanother.
4.ApplehasbeencriticizedbyEuropeanregulatorssinceithasrefusedtograntalicenseFairPlaytootherfirms.
5.Allmusiccanbeeasilyplayedonnon-iPodmusicdevicesfromSonyorMicrosoftwithouttoomuchfiddling.
6.AppledependsfarmoreonDRMratherthanbrandingforitsdominanceofthedigitalmusicdevices.
7.IfDRMwascancelled,Sonywouldcertainlydominatetheinternationaldigitalmusicmarket.
Questions8-10
ChoosetheappropriatelettersA-Dandwritetheminboxes8-10onyouranswesheet.
8.WhichofthefollowingstatementsaboutMr.Jobs’ideaofDRMisNOTTRUE?
A.DRMplacesrestrictionsonconsumer’choiceofdigitalmusicproductsavailable.
B.DRMcomplesiTunesbuyerstoswitchtoadevicemadebySonyorMicrosoft.
C.DRMconstitutesabarrierforpotentialconsumerstoenterdigitalmusicmarkets.
D.DRMhindersdevelopmentofmorestoresandplayersandtechnicalinnovation.
9.Theword“unfazed”inline3ofparagraphE,means___________.
A.refused
B.welcomed
C.notbothered
D.notwellreceived
10.WhichofthefollowingstatementsisTRUEifDRMwasscapped?
A.Sonywouldgainthemostprofit.
B.Morecustomerswouldbe“lockedin”.
C.Asuddenincreaseinpiracywouldoccur.
D.Online-musicsaleswouldprobablydecrease.
Questions11-14
Completethenotesbelow.
ChooseNOMORETHANTHREEWORDSfromReadingPassage1foreachanswer.
Writeyouranswersinboxes11-14onyouranswersheet.
Mr.SteveJobs,thebossofApple,explainsthereasonwhyheusedtodefendDRM,sayingthatthecompanywasforcedtodoso:therecordcompanieswouldmaketheirmusicaccessibleto…11...onlyiftheyagreedtoprotectitusingDRM;theycanstill…12…iftheDRMsystemiscompromised.HealsoprovidesthereasonwhyAppledidnotlicenseFairPlaytoothers:thecompanyreliesonthemto…13….ButnowhechangeshismindwithapossibleexpectationthatEurope’sregulatorswouldnottroublehimanymoreinthefuture.Heproposesthatthosewhoareunsatisfactorywiththecurrentsituationindigitalmusicmarketshould…14…towardspersuadethemusiccompaniestoselltheirmusicDRM-free.
Don't wash those fossils!
Standard museum practice can wash away DNA.
1.Washing, brushing and varnishing fossils — all standard conservation treatments used by many fossil hunters and museum curators alike — vastly reduces the chances of recovering ancient DNA.
2.Instead, excavators should be handling at least some of their bounty with gloves, and freezing samples as they are found, dirt and all, concludes a paper in the Proceedings of the National Academy of Sciences today.
3.Although many palaeontologists know anecdotally that this is the best way to up the odds of extracting good DNA, Eva-Maria Geigl of the Jacques Monod Institute in Paris, France, and her colleagues have now shown just how important conservation practices can be.This information, they say, needs to be hammered home among the people who are actually out in the field digging up bones.
4.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.The fossils were dug up at a site in France at two different times — either in 1947, and stored in a museum collection, or in 2004, and conserved in sterile conditions at -20 oC.
5.The team's attempts to extract DNA from the 1947 bones all failed.The newly excavated fossils, however, all yielded DNA.
6.Because the bones had been buried for the same amount of time, and in the same conditions, the conservation method had to be to blame says Geigl."As much DNA was degraded in these 57 years as in the 3,200 years before," she says.
Wash in, wash out
7.Because many palaeontologists base their work on the shape of fossils alone, their methods of conservation are not designed to preserve DNA, Geigl explains.
8.The biggest problem is how they are cleaned.Fossils are often washed together on-site in a large bath, which can allow water — and contaminants in the form of contemporary DNA — to permeate into the porous bones."Not only is the authentic DNA getting washed out, but contamination is getting washed in," says Geigl.
9.Most ancient DNA specialists know this already, says Hendrik Poinar, an evolutionary geneticist at McMaster University in Ontario, Canada.But that doesn't mean that best practice has become widespread among those who actually find the fossils.
10.Getting hold of fossils that have been preserved with their DNA in mind relies on close relationships between lab-based geneticists and the excavators, says palaeogeneticist Svante P bo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.And that only occurs in exceptional cases, he says.
11.P bo's team, which has been sequencing Neanderthal DNA, continually faces these problems."When you want to study ancient human and Neanderthal remains, there's a big issue of contamination with contemporary human DNA," he says.
12.This doesn't mean that all museum specimens are fatally flawed, notes P bo.The Neanderthal fossils that were recently sequenced in his own lab, for example, had been part of a museum collection treated in the traditional way.But P bo is keen to see samples of fossils from every major find preserved in line with Geigl's recommendations — just in case.
Warm and wet
13.Geigl herself believes that, with cooperation between bench and field researchers, preserving fossils properly could open up avenues of discovery that have long been assumed closed.
14.Much human cultural development took place in temperate regions.DNA does not survive well in warm environments in the first place, and can vanish when fossils are washed and treated.For this reason, Geigl says, most ancient DNA studies have been done on permafrost samples, such as the woolly mammoth, or on remains sheltered from the elements in cold caves — including cave bear and Neanderthal fossils.
15.Better conservation methods, and a focus on fresh fossils, could boost DNA extraction from more delicate specimens, says Geigl.And that could shed more light on the story of human evolution.
(640 words nature )
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
Questions 1-6
Answer the following questions by using NO MORE THAN THREE WORDS for each answer.
1.How did people traditionally treat fossils?
2.What suggestions do Geigl and her colleagues give on what should be done when fossils are found?
3.What problems may be posed if fossil bones are washed on-site? Name ONE.
4.What characteristic do fossil bones have to make them susceptible to be contaminated with contemporary DNA when they are washed?
5.What could be better understood when conservation treatments are improved?
6.The passage mentioned several animal species studied by researchers.How many of them are mentioned?
Questions 7-11
Do the following statements agree with the information given in the passage? Please write TRUE if the statement agrees with the writer FALSE if the statement does not agree with the writer NOT GIVEN if there is no information about this in the passage.
7.In their paper published in the Proceedings of the National Academy of Sciences，Geigl and her colleagues have shown what conservation practices should be followed to preserve ancient DNA.
8.The fossil bones that Geigl and her colleagues studied are all from the same aurochs.
9.Geneticists don't have to work on site.
10.Only newly excavated fossil bones using new conservation methods suggested by Geigl and her colleagues contain ancient DNA.
11.Paabo is still worried about the potential problems caused by treatments of fossils in traditional way.
Questions 12-13
Complete the following the statements by choosing letter A-D for each answer.
12.“This information” in paragraph 3 indicates:
[A] It is critical to follow proper practices in preserving ancient DNA.
[B] The best way of getting good DNA is to handle fossils with gloves.
[C] Fossil hunters should wear home-made hammers while digging up bones.
[D] Many palaeontologists know how one should do in treating fossils.
13.The study conducted by Geigl and her colleagues suggests:
[A] the fact that ancient DNA can not be recovered from fossil bones excavated in the past.
[B] the correlation between the amount of burying time and that of the recovered DNA.
[C] the pace at which DNA degrades.
[D] the correlation between conservation practices and degradation of DNA.
