Radioactivityoccursnaturally.Themainsourcecomesfromnaturalsourcesinspace,rocks,soilwaterandeventhehumanbodyitself.Thisiscalledbackgroundradiationandlevelsvaryfromplacetoplace,thoughtheaveragedoseisfairlyconstant.Theradiationwhichisofmostconcernisartificialradiationwhichresultsfromhumanactivities.Sourcesofthisincludethemedicaluseofradioactivematerials,falloutandcontaminationfromnuclearbombtests,dischargesfromthenuclearindustry,andthestorageanddumpingofradioactivewaste.Whileartificialradiationaccountsforasmallproportionofthetotal,itseffectscanbedisproportionate.Someoftheradioactivematerialsdischargedbyhumanactivityarenotfoundinnature,suchasplutonium(钚)whileotherswhicharefoundnaturallymaybedischargedindifferentphysicalandchemicalforms,allowingthemtospreadmorereadilyintotheenvironment,orperhapsaccumulateinthefood-chain.Manyoftheelementswhichourbodiesneedareproducedbythenuclearindustryasradioactiveisotopesorvariants.Someofthesearereleasedintotheenvironment,forexampleiodineandcarbon,twocommonelementsusedbyourbodies.Ourbodiesdonotknowthedifferencebetweenanelementwhichisradioactiveandonewhichisnot.Soradioactiveelementscanbeabsorbedintolivingtissues,bonesorthebleed,wheretheycontinuetogiveoffradiation.Radioactivestrontiumbehaveslikecalcium-anessentialingredientinourbones-inourbodies.Strontiumdepositsinthebonessendradioactivityintothebonemarrow,wherethebloodcellsareformed,pausingleukemia.Inmostcases,celldeathonlybecomessignificantwhenlargenumbersofcellsarekilled,andtheeffectsofcelldeaththereforeonlybecomeapparentatcomparativelyhighdoselevels.Ifadamagedcellisabletosurvivearadiationdose,thesituationisdifferent.Inmanycasestheeffectofthecelldamagemayneverbecomeapparent.Afewmalfunctioningcellwillnotsignificantlyaffectanorganwherethelargemajorityarestillbehavingnormally.However,iftheaffectedcellisagermcellwithintheovariesortesticles,thesituationisdifferent.IonizingradiationcandamageDNA,themoleculewhichactsasthecell's"instructionbook".Ifthatgermcelllaterformsachild,allofthechild'scellswillcarrythesamedefect.ThelocalizedchemicalalterationofDNAinasinglecellmaybeexpressedasaninheritedabnormalityinoneormanyfuturegenerations.Inthesamewaythatasomaticcell(体细胞)inbodytissueischangedinsuchawaythatitoritsdescendantsescapethecontrolprocesseswhichnormallycontrolcellreplication,thegroupofcellsformedmaycontinuetohaveaselectiveadvantageingrowthoversurroundingtissue.Itmayultimatelyincreasesufficientlyinsizetoformadetectablecancerandinsomecasescausedeathbyspreadinglocallyortootherpartsofthebody.Whilethereisnowbroadagreementabouttheeffectsofhigh-levelradiation,thereiscontroversyoverthelong-termeffectoflow-leveldoses.Thisiscomplicatedbythelengthoftimeittakesforeffectstoshowup,thefactthatthepopulationsbeingstudiedaresmallandexactdosesarehardtocalculate.Allthatcanbesaidisthatpredictionsmadeabouttheeffectsofagivendosevary.Agrowingnumberofscientistspointtoevidencethatthereisadisproportionatelyhighriskfromlowdosesofradiation.Othersassumeadirectlyproportionatelinkbetweenthereceiveddoseandtheriskofcancerforalllevelsofdose,whiletherearesomewhoclaimthatatlowdosesthereisadisproportionatelylowlevelofrisk.Questions56to60Fillintheblanksbelowwithinformationfromthepassage,usingnomorethanthreewordsforeachblank.

{{B}}Section A{{/B}}

Some bacteria______extremely harmful, but______are regularly used in producing cheeses, crackers and many other foods.

Whatcanwedotostaywell?It'sagoodideatoexercise,eatfruit,vegetables,anddrinklotsofwater.Wealsoknowthingsnottodo:it'sabadideatoeatalotofjunkfoodortobeacouchpotato.It'saterribleideatosmoke.However,thereisalotofnewinformationabouthealth,someofwhichissurprising.Severalbeveragesaregoodforthehealth.OrangejuicehasvitaminC.Milkhascalcium.Blackteaandgreenteaaregoodforhealthtoobecausetheyhaveantioxidantsthatfightdiseasessuchascancerandheartdisease.Butmostpeopledon'tknowa-boutcocoa.Theyenjoythesweet,chocolatybeverage,buttheydon'tknowthatithasmoreantioxidantsthantea!Toomuchstressisnotgoodforphysicalhealthbecauseitmakesyourbloodpressuregoup.Nowweknowmore.Somestressischronic,whichmeansthatitlastsalongtime—formanymonthsoryears.Chronicstresscanmakepeopleold.Aspeoplegetolder,theygetgrayhairandwrinklesintheirskin,andtheireyesightandhearingbecomeworse.Thisisnormal.Butchronicstressmakespeopleagefaster.AscientistattheUniversityofCaliforniastudiesstress.Shecannowidentifyhowstressmakespeopleage.Itcandamagethebody'sDNA.Thelessonfromthisisclear.Weneedtolearntorelax.Oneeasyandcheapwaytohelpbothyourphysicalandmentalhealthisjusttosleepeighthoursormoreeverynight,butmoreandmorepeoplearenotsleepingenough.AccordingtotheWorldHealthOrganization,overhalfthepeopleintheworldmaybesleep-deprived,whichmeanstheydon'tgetenoughsleep.Sleep-deprivedpeopleoftenhavemedicalproblems,suchashighbloodpressure,diabetes,andheartproblems.Itisalsomoredifficultforthemtomakedecisions.Butthereisanotherreason.AnewstudyfromGermanyfoundthatsleepmakespeoplesmarter.Thestudyshowsthatthebraincontinuestoworkduringsleepandhelpsthesleepertoworkonproblems.Youdidn'tdoyourhomeworklastnight?Maybeyourbraincantellyourteacherthatyouwereworkinghardinyoursleep!Howmanylanguagesdoyouspeak?AstudyfromauniversityinCanadafoundsomethinginteresting.Bilingualpeople,whospeaktwolanguagesverywell,dobetteronteststhanpeoplewhospeakonlyonelanguage.Itseemstobementalexercisetoholdtwolanguagesinyourbrain.EllenBialystockofYorkUniversitysaysit's"likegoingtoabraingym".Questions71—75Completethesummarywithwordsfromthepassage,changingtheformwherenecessarywithnomorethanthreewordsforeachblank.Scientistsnowhavenewinformationaboutotherwaysto________.Somearequitesurprisinglyunknowntousbefore.Normally,inordertohavegoodphysicalandmentalhealth,weknowweshouldeatright,relax,sleep,andexerciseboththebodyand________.Hotchocolateisnowfoundtocontainmoreantioxidantswhicharecapableoffightingcertaindiseases.Researchshowsthatwecanslowdownourageingprocessbylearningto________.Itisalsoimportanttogetenoughsleepbecauselackofsleepwillcertainlyleadtomedicalproblemsormakeuslesssmart.Meanwhile,________peoplearereportedtobehavebetteronteststhanmonolingualonesbecausetheybenefitfrom________byholdingtwolanguages.

The game was cancelled because most of the team members______a match without a standard court.

{{B}}Part Ⅳ Cloze{{/B}}

Heartbeat of America New York—the Statue of Liberty, the skyscrapers, the beautiful shops on Fifth Avenue and the many theaters on Broadway. This is America's cultural capital. It is also her biggest city, with a population of nearly 8 million. In the summer it is hot, hot, hot and in the winter it can be very cold. Still there are hundreds of things to do and see all the year round. 【B1】______When people say "New York City" , they usually mean Manhattan. Most of the interesting shops, buildings and museums are here. In addition, Manhattan is the scene of New York's busy night life. In 1605, the first Europeans came to Manhattan from Holland. They bought the island from the Native Americans for a few glass necklaces worth about $26 today. 【B2】______It is also the most important banking center in the world. It is a street of " skyscrapers". These are those incredible, high buildings, which Americans invented, and built faster and higher than anyone else. Perhaps the two most spectacular skyscrapers in New York are the two towers of the New York World Trade Center. When the sun sets, their 110 floors shine like pure gold. 【B3】______Traffic jams can be terrible. It's usually quickest to go by subway. The New York subway is easy to use and quite cheap. The subway goes to almost every corner of Manhattan. But it is not safe to take the subway late at night because in some places you could get robbed. New York buses are also easy to use. You see more if you go by bus. There are more than 30,000 taxis in New York. Taxis do not go outside the city. However, they will go to the airports. In addition to the taxi fare, people give the taxi driver a tip of 15 percent of the fare's value. 【B4】______It is surprisingly big, with lakes and woods, as well as organized recreation areas. New Yorkers love Central Park, and they use it all the time: In the winter, they go ice-skating, and in the summer roller-skating. They play ball, ride horses and have picnics. They go bicycling and boating. There is even a children's zoo, with wild birds and animals. Along the east side of Central Park runs Fifth Avenue, once called " Millionaire's Row. " In the 19th century, the richest men in America built their magnificent homes here. It is still the most fashionable street in the city, with famous department stores. 【B5】______But away from the bright lights and elegant clothes of Broadway are many smaller theaters. Their plays are called " off-Broadway" and are often more unusual than the Broadway shows. As well as many theaters, New York has a famous opera house. This is the Metropolitan, where international stars sing from September until April. Carnegie Hall is the city's more popular concert hall. But night life in New York offers more than classical music and theater. There are hundreds of nightclubs where people go to eat and dance. Questions 61 to 65Choose from the sentences A—G the one which best fits each gap of 61—65. There are two extra sentences which you do not need to use.A. Broadway is the street where you will find New York's best-known theaters.B. Manhattan is a rich city.C. Like every big city, New York has its own traffic system.D. Central Park is a beautiful green oasis in the middle of New York's concrete desert.E. Two towers of the New York World Trade Center are spectacular.F. Manhattan is the real center of the city.G. Wall Street in Manhattan is the financial heart of the USA.

Where was George Weekes bom?

{{B}}Section D{{/B}}

—David. It's good to meet you. ______—Three years, but I'm thinking about stopping soon.—Why's that?—It's time for a change, and I can't work the long hours any more.

Tom: Did you hear the weather forecast for tomorrow? Patrick: I think it's going to be clear and sunny. Tom: That's great. We can do something outdoors then. Patrick: ______Tom: Yeah. I think there's a live outdoor concert by the river. Patrick: Oh yeah. I heard about that, too. Let's go and check it out.

I'm sorry but you need find another parking space, because if any vehicle ______on these premises, it shall be towed away.

{{B}}Section A{{/B}}

Waiter: Would you like to have one bill or separate bills, sir? John: It's my treat. One bill, please.Paul: You paid last time. ______John: Well, all right if you insist. But next time you must let me pay.

The Dead Sea, the lowest point on earth and the largest "Natural Spa" in the world, is also one of the world's true natural wonders and a unique tourism destination. Starting with the Dead Sea itself, a one-of-a-kind body of water, 417 meters(1,373 ft.)below sea level with mineral-rich waters and mud flow with natural health and beautifying effect acclaimed globally. But that's not all. Visitors to the Dead Sea come to a world of blue skies, year-round sunshine, magnificent natural landscape, and extraordinary touring options, such as thrilling encounters with history and exploration of the living desert.

{{B}}Part I Listening Comperhension{{/B}}

{{B}}Part Ⅱ Vocabulary and Structure{{/B}}

We explained why his plan doesn't work, but he is very______and won't change his mind.

The cost of staging the year 2000 Olympics in Sydney is estimated to be a staggering $960 million , but the city is preparing to reap the financial benefits that ensue from holding such an international event by emulating the commercial success of Los Angeles, the only city yet to have made a demonstrable profit from the Games in 1984. At precisely 4'- 20 a. m. on Friday the 24th of September 1993, it was announced that Sydney had beaten five other competing cities around the world, and Australians everywhere, not only Sydneysiders, were justifiably proud of the result. But, if Sydney had lost the bid, would the taxpayers of NSW and of Australia have approved of governments spending millions of dollars in a failed and costly exercise? There may have been some consolation in the fact that the bid came in $1 million below the revised budget and $5 million below the original budget of $29 million formulated in mid-1991. However, the final cost was the considerable sum of $24 million, the bulk of which was paid for by corporate and community contributions, merchandising, licensing, and the proceeds of lotteries, with the NSW Government, which had originally been willing to spend up to $10 million, contributing some $2 million. The Federal Government's grant of $5 million meant, in effect, that the Sydney bid was financed by every Australian taxpayer. Prior to the announcement of the winning city, there was considerable debate about the wisdom of taking financial risks of this kind at a time of economic recession. Others argued that 70 percent of the facilities were already in place, and all were on government-owned land, removing some potential areas of conflict which troubled previous Olympic bidders. The former NSW Premier, Mr. Nick Greiner, went on record as saying that the advantage of having the Games... "is not that you are going to have $7. 4 billion in extra gross domestic product over the next 14 years ... I think the real point of the Games is the psychological change, the catalyst of confidence... apart from the other more obvious reasons, such as the building of sporting facilities, tourism, and things of that nature. " However, the dubiousness of the benefits that Melbourne, an unsuccessful bidder for the 1988 Olympic Games, received at a time when the State of Victoria was still in economic turmoil meant many corporate bodies were unenthusiastic. There is no doubt that Sydney's seductive physical charms caused the world's media to compare the city favorably to its rivals Beijing, Berlin, Manchester, and Istanbul. Mr. Godfrey Santer, the Australian Tourist Commission's Manager of Corporate Planning Services, stated that soon after the bid was made, intense media focus was already having a beneficial effect on in-bound tourism. Developers and those responsible for community development projects eagerly pointed to the improvements taking place to the existing infrastructure of the city, the creation of employment, and especially the building of sporting facilities, all of which meet the needs of the community and help to attract more tourists. At Homebush Bay $300 million was spent providing the twin athletic arenas and the "high-tech" Aquatic Centre. However, perhaps the most impressive legacy was the new attitude shown towards both industrial relations and environmental problems. The high-profile nature of the bid: and the perception that it must proceed smoothly created a unique attitude of co-operation between the workforce and employers involved in the construction of the Olympic Village at Homebush Bay. The improvements included the lack of strikes, the breaking down of demarkation barriers, and the completion of projects within budget and ahead of time. Questions 66 to 70Answer the following questions with the information given in the passage in a maximum of 15 words for each question.

Therapy is to cure as treatment is to______.