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. A European spacecraft took off today to spearhead the search for another "Earth" among the stars.

2. The Corot space telescope blasted off aboard a Russian Soyuz rocket from the Baikonur cosmodrome in Kazakhstan shortly after 2.20pm.

3. Corot, short for convection rotation and planetary transits, is the first instrument capable of finding small rocky planets beyond the solar system. Any such planet situated in the right orbit stands a good chance of having liquid water on its surface, and quite possibly life, although a leading scientist involved in the project said it was unlikely to find "any little green men".

4. Developed by the French space agency, CNES, and partnered by the European Space Agency (ESA), Austria, Belgium, Germany, Brazil and Spain, Corot will monitor around 120,000 stars with its 27cm telescope from a polar orbit 514 miles above the Earth. Over two and a half years, it will focus on five to six different areas of the sky, measuring the brightness of about 10,000 stars every 512 seconds.

5. "At the present moment we are hoping to find out more about the nature of planets around stars which are potential habitats. We are looking at habitable planets, not inhabited planets. We are not going to find any little green men," Professor Ian Roxburgh, an ESA scientist who has been involved with Corot since its inception, told the BBC Radio 4 Today programme.

6. Prof Roxburgh said it was hoped Corot would find "rocky planets that could develop an atmosphere and, if they are the right distance from their parent star, they could have water".

7. To search for planets, the telescope will look for the dimming of starlight caused when an object passes in front of a star, known as a "transit". Although it will take more sophisticated space telescopes planned in the next 10 years to confirm the presence of an Earth-like planet with oxygen and liquid water, Corot will let scientists know where to point their lenses.

8. Measurements of minute changes in brightness will enable scientists to detect giant Jupiter-like gas planets as well as small rocky ones. It is the rocky planets - that could be no bigger than about twice the size of the Earth - which will cause the most excitement. Scientists expect to find between 10 and 40 of these smaller planets.

9. Corot will also probe into stellar interiors by studying the acoustic waves that ripple across the surface of stars, a technique called "asteroseismology".

10. The nature of the ripples allows astronomers to calculate a star’s precise mass, age and chemical composition.

11. "A planet passing in front of a star can be detected by the fall in light from that star. Small oscillations of the star also produce changes in the light emitted, which reveal what the star is made of and how they are structured internally. This data will provide a major boost to our understanding of how stars form and evolve," Prof Roxburgh said.

12. Since the discovery in 1995 of the first "exoplanet" - a planet orbiting a star other than the Sun - more than 200 others have been found by ground-based observatories.

13. Until now the usual method of finding exoplanets has been to detect the "wobble" their gravity imparts on parent stars. But only giant gaseous planets bigger than Jupiter can be found this way, and they are unlikely to harbour life.

14. In the 2010s, ESA plans to launch Darwin, a fleet of four or five interlinked space telescopes that will not only spot small rocky planets, but analyse their atmospheres for signs of biological activity.

15. At around the same time, the US space agency, Nasa, will launch Terrestrial Planet Finder, another space telescope designed to locate Earth-like planets.

Choose the appropriate letter from A-D for question 1.

1. Corot is an instrument which

(A) can help to search for certain planets

(B) is used to find planets in the orbit

(C) can locate planets with human beings

(D) can spot any planets with water.

Do the following statements agree with the information given in the reading passage? For questions 2-5 write

TRUE if the statement agrees with the information

FALSE if the statement contraicts the information

NOT GIVEN if there is no information on this in the passage

2. Scientists are trying to find out about the planets that can be inhabited.

3. BBC Radio 4 recently focuses on the broadcasting of Corot.

4. Passing objects might cause a fall in light.

5. Corot can tell whether there is another Earth-like planet.

Based on your reading of the passage, complete the sentences below with words taken from the passage. Use NO MORE THAN THREE WORDS for each answer.

With measurements, scientists will be able to search for some gaseous and rocky planets. They will be extremely excited if they can discover some small 6. __________, the expected number of which could be up to 7. __________ .

Corot will enable scientists to study the 8. __________ of stars. In this way, a star’s mass, age and chemical composition can be calculated.

According to Prof Roxburgh, changes in light can be caused by passing planets or star 9. __________. The related statistics can gain us a better 10. __________ of the star formation and evolvement.

Observatories have found many exoplanets, which are 11. __________ other stars than the Sun. The common way used in finding exoplanets can only detect huge gas planets, which do not 12. ___________ .

With the launching of Darwin, astronomers will be able to analyse whether those rocky planets have 13. __________ for life.

How shops can exploit people's herd mentality to increase sales

1.A TRIP to the supermarket may not seem like an exercise in psychological warfare—but it is.Shopkeepers know that filling a store with the aroma of freshly baked bread makes people feel hungry and persuades them to buy more food than they had intended.Stocking the most expensive products at eye level makes them sell faster than cheaper but less visible competitors.Now researchers are investigating how “swarm intelligence” (that is，how ants，bees or any social animal，including humans，behave in a crowd) can be used to influence what people buy.

2.At a recent conference on the simulation of adaptive behaviour in Rome，Zeeshan-ul-hassan Usmani，a computer scientist from the Florida Institute of Technology，described a new way to increase impulse buying using this phenomenon.Supermarkets already encourage shoppers to buy things they did not realise they wanted: for instance，by placing everyday items such as milk and eggs at the back of the store，forcing shoppers to walk past other tempting goods to reach them.Mr Usmani and Ronaldo Menezes，also of the Florida Institute of Technology，set out to enhance this tendency to buy more by playing on the herd instinct.The idea is that，if a certain product is seen to be popular，shoppers are likely to choose it too.The challenge is to keep customers informed about what others are buying.

3.Enter smart-cart technology.In Mr Usmani's supermarket every product has a radio frequency identification tag，a sort of barcode that uses radio waves to transmit information，and every trolley has a scanner that reads this information and relays it to a central computer.As a customer walks past a shelf of goods，a screen on the shelf tells him how many people currently in the shop have chosen that particular product.If the number is high，he is more likely to select it too.

4.Mr Usmani's “swarm-moves” model appeals to supermarkets because it increases sales without the need to give people discounts.And it gives shoppers the satisfaction of knowing that they bought the “right” product—that is，the one everyone else bought.The model has not yet been tested widely in the real world，mainly because radio frequency identification technology is new and has only been installed experimentally in some supermarkets.But Mr Usmani says that both Wal-Mart in America and Tesco in Britain are interested in his work，and testing will get under way in the spring.

5.Another recent study on the power of social influence indicates that sales could，indeed，be boosted in this way.Matthew Salganik of Columbia University in New York and his colleagues have described creating an artificial music market in which some 14,000 people downloaded previously unknown songs.The researchers found that when people could see the songs ranked by how many times they had been downloaded，they followed the crowd.When the songs were not ordered by rank，but the number of times they had been downloaded was displayed，the effect of social influence was still there but was less pronounced.People thus follow the herd when it is easy for them to do so.

6.In Japan a chain of convenience shops called RanKing RanQueen has been ordering its products according to sales data from department stores and research companies.The shops sell only the most popular items in each product category，and the rankings are updated weekly.Icosystem，a company in Cambridge，Massachusetts，also aims to exploit knowledge of social networking to improve sales.

7.And the psychology that works in physical stores is just as potent on the internet.Online retailers such as Amazon are adept at telling shoppers which products are popular with like-minded consumers.Even in the privacy of your home，you can still be part of the swarm.

Questions 1-6

Complete the sentences below with words taken from the reading passage.Use NO MORE THAN THREE WORDS for each answer.

1.Shopowners realize that the smell of _______________ can increase sales of food products.

2.In shops，products shelved at a more visible level sell better even if they are more _______________.

3.According to Mr.Usmani，with the use of “swarm intelligence” phenomenon，a new method can be applied to encourage _______________.

4.On the way to everyday items at the back of the store，shoppers might be tempted to buy _______________.

5.If the number of buyers shown on the _______________ is high，other customers tend to follow them.

6.Using the “swarm-moves” model，shopowners do not have to give customers _______________ to increase sales.

newweapontofightcancer

1.Britishscientistsarepreparingtolaunchtrialsofaradicalnewwaytofightcancer,whichkillstumoursbyinfectingthemwithviruseslikethecommoncold.

2.Ifsuccessful,virustherapycouldeventuallyformathirdpillaralongsideradiotherapyandchemotherapyinthestandardarsenalagainstcancer,whileavoidingsomeofthedebilitatingside-effects.

3.LeonardSeymour,aprofessorofgenetherapyatOxfordUniversity,whohasbeenworkingonthevirustherapywithcolleaguesinLondonandtheUS,willleadthetrialslaterthisyear.CancerResearchUKsaidyesterdaythatitwasexcitedbythepotentialofProfSeymour’spioneeringtechniques.

4.Oneofthecountry’sleadinggeneticists,ProfSeymourhasbeenworkingwithvirusesthatkillcancercellsdirectly,whileavoidingharmtohealthytissue."Inprinciple,you’vegotsomethingwhichcouldbemanytimesmoreeffectivethanregularchemotherapy,"hesaid.

5.Cancer-killingvirusesexploitthefactthatcancercellssuppressthebody’slocalimmunesystem."Ifacancerdoesn’tdothat,theimmunesystemwipesitout.Ifyoucangetavirusintoatumour,virusesfindthemaverygoodplacetobebecausethere’snoimmunesystemtostopthemreplicating.Youcanregarditasthecancer’sAchilles’heel."

6.Onlyasmallamountofthevirusneedstogettothecancer."Theyreplicate,yougetamillioncopiesineachcellandthecellburstsandtheyinfectthetumourcellsadjacentandrepeattheprocess,"saidProfSeymour.

7.Preliminaryresearchonmiceshowsthatthevirusesworkwellontumoursresistanttostandardcancerdrugs."It’saninterestingpossibilitythattheymayhaveanadvantageinkillingdrug-resistanttumours,whichcouldbequitedifferenttoanythingwe’vehadbefore."

8.Researchershaveknownforsometimethatvirusescankilltumourcellsandsomeaspectsoftheworkhavealreadybeenpublishedinscientificjournals.Americanscientistshavepreviouslyinjectedvirusesdirectlyintotumoursbutthistechniquewillnotworkifthecancerisinaccessibleorhasspreadthroughoutthebody.

9.ProfSeymour’sinnovativesolutionistomaskthevirusfromthebody’simmunesystem,effectivelyallowingthevirusestodowhatchemotherapydrugsdo-spreadthroughthebloodandreachtumourswherevertheyare.Thebighurdlehasalwaysbeentofindawaytodelivervirusestotumoursviathebloodstreamwithoutthebody’simmunesystemdestroyingthemontheway.

10."Whatwe’vedoneismakechemicalmodificationstothevirustoputapolymercoataroundit-it’sastealthviruswhenyouinjectit,"hesaid.

11.Afterthestealthvirusinfectsthetumour,itreplicates,butthecopiesdonothavethechemicalmodifications.Iftheyescapefromthetumour,thecopieswillbequicklyrecognisedandmoppedupbythebody’simmunesystem.

12.Thetherapywouldbeespeciallyusefulforsecondarycancers,calledmetastases,whichsometimesspreadaroundthebodyafterthefirsttumourappears."There’sanawfulstatisticofpatientsinthewest...withmalignantcancers;75%ofthemgoontodiefrommetastases,"saidProfSeymour.

13.Twovirusesarelikelytobeexaminedinthefirstclinicaltrials:adenovirus,whichnormallycausesacold-likeillness,andvaccinia,whichcausescowpoxandisalsousedinthevaccineagainstsmallpox.Forsafetyreasons,bothwillbedisabledtomakethemlesspathogenicinthetrial,butProfSeymoursaidheeventuallyhopestousenaturalviruses.

14.Thefirsttrialswilluseuncoatedadenovirusandvacciniaandwillbedeliveredlocallytolivertumours,inordertoestablishwhetherthetreatmentissafeinhumansandwhatdoseofviruswillbeneeded.Severalmoreyearsoftrialswillbeneeded,eventuallyalsoonthepolymer-coatedviruses,beforethetherapycanbeconsideredforuseintheNHS.Thoughtheapproachwillbeexaminedatfirstforcancersthatdonotrespondtoconventionaltreatments,ProfSeymourhopesthatonedayitmightbeappliedtoallcancers.

Questions1-6

Dothefollowingstatementsagreewiththeinformationgiveninthereadingpassage?Forquestions1-6write

TRUEifthestatementagreeswiththeinformation

FALSEifthestatementcontradictstheinformation

NOTGIVENifthereisnoinformationonthisinthepassage

1.Virustherapy,ifsuccessful,hasanadvantageineliminatingside-effects.

2.CancerResearchUKisquitehopefulaboutProfessorSeymour’sworkonthevirustherapy.

3.Viruscankillcancercellsandstopthemfromgrowingagain.

4.Cancer’sAchilles’heelreferstothefactthatvirusmaystaysafelyinatumorandreplicate.

5.Toinfectthecancercells,agooddealofvirusesshouldbeinjectedintothetumor.

6.Researchesonanimalsindicatethatviruscouldbeusedasanewwaytotreatdrug-resistanttumors.

Question7-9

Basedonthereadingpassage,choosetheappropriateletterfromA-Dforeachanswer.

7.Informationaboutresearchesonviruseskillingtumorcellscanbefound

(A)onTV

(B)inmagazines

(C)oninternet

(D)innewspapers

8.Totreattumorsspreadingoutinbody,researcherstryto

(A)changethebody’immunesystem

(B)injectchemotherapydrugsintobloodstream.

(C)increasetheamountofinjection

(D)disguisethevirusesonthewaytotumors.

9.Whenthechemicalmodifiedvirusintumorreplicates,thecopies

(A)willsoonescapefromthetumorandspreadout.

(B)willbewipedoutbythebody’simmunesystem.

(C)willbeimmediatelyrecognizedbytheresearchers.

(D)willeventuallystopthetumorfromspreadingout.

Questions10-13

Completethesentencesbelow.Chooseyouranswersfromthelistofwords.Youcanonlyuseeachwordonce.

NBTherearemorewordsinthelistthanspacessoyouwillnotusethemall.

Inthefirstclinicaltrials,scientistswilltryto……10……adenovirusandvaccinia,soboththeviruseswillbelesspathogenicthanthe……11…….Theseuncoatedviruseswillbeapplieddirectlytocertainareastoconfirmsafetyonhumanbeingsandtheright……12……needed.Theexperimentswillfirstlybe……13……tothetreatmentofcertaincancers

Howshopscanexploitpeople'sherdmentalitytoincreasesales

1.ATRIPtothesupermarketmaynotseemlikeanexerciseinpsychologicalwarfare—butitis.Shopkeepersknowthatfillingastorewiththearomaoffreshlybakedbreadmakespeoplefeelhungryandpersuadesthemtobuymorefoodthantheyhadintended.Stockingthemostexpensiveproductsateyelevelmakesthemsellfasterthancheaperbutlessvisiblecompetitors.Nowresearchersareinvestigatinghow“swarmintelligence”(thatis，howants，beesoranysocialanimal，includinghumans，behaveinacrowd)canbeusedtoinfluencewhatpeoplebuy.

2.AtarecentconferenceonthesimulationofadaptivebehaviourinRome，Zeeshan-ul-hassanUsmani，acomputerscientistfromtheFloridaInstituteofTechnology，describedanewwaytoincreaseimpulsebuyingusingthisphenomenon.Supermarketsalreadyencourageshopperstobuythingstheydidnotrealisetheywanted:forinstance，byplacingeverydayitemssuchasmilkandeggsatthebackofthestore，forcingshopperstowalkpastothertemptinggoodstoreachthem.MrUsmaniandRonaldoMenezes，alsooftheFloridaInstituteofTechnology，setouttoenhancethistendencytobuymorebyplayingontheherdinstinct.Theideaisthat，ifacertainproductisseentobepopular，shoppersarelikelytochooseittoo.Thechallengeistokeepcustomersinformedaboutwhatothersarebuying.

3.Entersmart-carttechnology.InMrUsmani'ssupermarketeveryproducthasaradiofrequencyidentificationtag，asortofbarcodethatusesradiowavestotransmitinformation，andeverytrolleyhasascannerthatreadsthisinformationandrelaysittoacentralcomputer.Asacustomerwalkspastashelfofgoods，ascreenontheshelftellshimhowmanypeoplecurrentlyintheshophavechosenthatparticularproduct.Ifthenumberishigh，heismorelikelytoselectittoo.

4.MrUsmani's“swarm-moves”modelappealstosupermarketsbecauseitincreasessaleswithouttheneedtogivepeoplediscounts.Anditgivesshoppersthesatisfactionofknowingthattheyboughtthe“right”product—thatis，theoneeveryoneelsebought.Themodelhasnotyetbeentestedwidelyintherealworld，mainlybecauseradiofrequencyidentificationtechnologyisnewandhasonlybeeninstalledexperimentallyinsomesupermarkets.ButMrUsmanisaysthatbothWal-MartinAmericaandTescoinBritainareinterestedinhiswork，andtestingwillgetunderwayinthespring.

5.Anotherrecentstudyonthepowerofsocialinfluenceindicatesthatsalescould，indeed，beboostedinthisway.MatthewSalganikofColumbiaUniversityinNewYorkandhiscolleagueshavedescribedcreatinganartificialmusicmarketinwhichsome14,000peopledownloadedpreviouslyunknownsongs.Theresearchersfoundthatwhenpeoplecouldseethesongsrankedbyhowmanytimestheyhadbeendownloaded，theyfollowedthecrowd.Whenthesongswerenotorderedbyrank，butthenumberoftimestheyhadbeendownloadedwasdisplayed，theeffectofsocialinfluencewasstilltherebutwaslesspronounced.Peoplethusfollowtheherdwhenitiseasyforthemtodoso.

6.InJapanachainofconvenienceshopscalledRanKingRanQueenhasbeenorderingitsproductsaccordingtosalesdatafromdepartmentstoresandresearchcompanies.Theshopssellonlythemostpopularitemsineachproductcategory，andtherankingsareupdatedweekly.Icosystem，acompanyinCambridge，Massachusetts，alsoaimstoexploitknowledgeofsocialnetworkingtoimprovesales.

7.Andthepsychologythatworksinphysicalstoresisjustaspotentontheinternet.OnlineretailerssuchasAmazonareadeptattellingshopperswhichproductsarepopularwithlike-mindedconsumers.Evenintheprivacyofyourhome，youcanstillbepartoftheswarm.

Questions1-6

Completethesentencesbelowwithwordstakenfromthereadingpassage.UseNOMORETHANTHREEWORDSforeachanswer.

1.Shopownersrealizethatthesmellof_______________canincreasesalesoffoodproducts.

2.Inshops，productsshelvedatamorevisiblelevelsellbettereveniftheyaremore_______________.

3.AccordingtoMr.Usmani，withtheuseof“swarmintelligence”phenomenon，anewmethodcanbeappliedtoencourage_______________.

4.Onthewaytoeverydayitemsatthebackofthestore，shoppersmightbetemptedtobuy_______________.

5.Ifthenumberofbuyersshownonthe_______________ishigh，othercustomerstendtofollowthem.

6.Usingthe“swarm-moves”model，shopownersdonothavetogivecustomers_______________toincreasesales.