Insomecountriesaroundtheworldmenandwomentendtohavetheirchildrenlateinlife.Whatarethereasonsforthisdevelopment?Whataretheeffectsonsocietyandfamilylife?
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
搬运管子、工字铁粱等长形物体时,应注意防止物件甩动,以免打伤附近人员或设备
探水地点不必要安设专用电话。
矿井建设和延深中,当开拓到设计水平时,必须在建成防、排水系统后方可开拓掘进。
在使用微倾水准仪测量中,读数后要检查符合气泡是否居中,如不居中则调居中后再读数,并取两次读数的平均值作为最后读数结果。
隔离式自救器在使用中外壳体会发热,当感到呼吸温度高时,可取下鼻夹和口具。
矿井供电电缆可以用普通橡套电缆。
在地形图上,两条相邻等高线之间的高差称为等高距。在等高距一定的情况下,等高线之间的距离越小,则表示地面坡度也越小
过滤式自救器只能使用1次,用后就报废。
煤矿建设、生产阶段,必须对揭露的煤层、断层、褶皱、岩浆岩体、陷落柱、含水岩层,矿井涌水量及主要出水点等进行观测及描述,综合分析,实施地质预测、预报。
误差(或中误差)的绝对值与其真值(或平均值)之比通常用1/N的形式表示,叫做精度(或相对误差)