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.
At first he got what he wanted by a simple process ofexchange.The smith who had not the time to look after land or cattle was glad to take meat or grain from the farmer inexchange for an axe or a plough.But as more and more goods which had no fixed exchange value came on the market,exchange became too complicated to be satisfactory.Another problem arose when those who made things wanted to get stocks of wood or leather,or iron,but had nothing to offer in exchange until their finished goods were ready. Thus the difficulties of exchange led by degrees to the invention of money.In some countries easily handled things like seeds or shells were given a certain value and the farmer,instead of paying the smith for a new axe by giving him some meat or grain,gave him so many shells.If the smith had any shells left when he had bought his food,he could get stocks of the raw materials of his trade.In some countries quite large things such as cows or camels or even big flat stones were used for trade.Later,pieces of metal,bearing values according to the rarity of the metal and the size of the pieces,or coins were used.Money as we know it had arrived.
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
C nothing could be offered in exchangeD the exchange of one thing for another became too complicated
3.The best title for this passage is _____.
A What is money
B What are money's functions.
C The importance of money
D The beginning of money
1、C;2、D;3、D
暫無解析
-----Wouldyoumindmyusingyourpen?
-----_______________.
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.
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古生物學(xué)家
Aurochs歐洲野牛
Neanderthal(人類學(xué))尼安德特人，舊石器時代的古人類。
Permafrost(地理)永凍層
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.
Thelocalgovernmentwill_____morecollegesformorestudentstoreceivehighereducation.
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 古生物學(xué)家
Aurochs 歐洲野牛
Neanderthal (人類學(xué))尼安德特人，舊石器時代的古人類。
Permafrost (地理)永凍層
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.
