专八英语考试阅读理解试题附答案
专八英语考试阅读理解试题附答案1
Canelectricitycausecancer?Inasocietythatliterallyrunsonelectricpower,theveryideaseemspreposterous.Butformorethanadecade,agrowingbandofscientistsandjournalistshaspointedtostudiesthatseemtolinkexposuretoelectromagneticfieldswithincreasedriskofleukemiaandothermalignancies.Theimplicationsareunsettling,tosaytheleast,sinceeveryonecomesintocontactwithsuchfields,whicharegeneratedbyeverythingelectrical,frompowerlinesandantennastopersonalcomputersandmicro-waveovens.Becauseevidenceonthesubjectisinconclusiveandoftencontradictory,ithasbeenhardtodecidewhetherconcernaboutthehealtheffectsofelectricityislegitimate—ortheworstkindofparanoia.
NowthealarmistshavegainedsomequalifiedsupportfromtheU.S.EnvironmentalProtectionAgency.Intheexecutivesummaryofanewscientificreview,releasedindraftformlatelastweek,theEPAhasputforwardwhatamountstothemostseriousgovernmentwarningtodate.Theagencytentativelyconcludesthatscientificevidence“suggestsacasuallink”betweenextremelylow-frequencyelectromagneticfields—thosehavingverylongwave-lengths—andleukemia,lymphomaandbraincancer,WhilethereportfallsshortofclassifyingELFfieldsasprobablecarcinogens,itdoesidentifythecommon60-hertzmagneticfieldas“apossible,butnotproven,causeofcancerinhumans.”
Thereportisnoreasontopanic—oreventolostsleep.Ifthereisacancerrisk,itisasmallone.TheevidenceisstillsocontroversialthatthedraftstirredagreatdealofdebatewithintheBushAdministration,andtheEPAreleaseditoverstrongobjectionsfromthePentagonandtheWhitHouse.Butnownoonecandenythattheissuemustbetakenseriouslyandthatmuchmoreresearchisneeded.
Attheheartofthedebateisasimpleandwell-understoodphysicalphenomenon:Whenanelectriccurrentpassesthrougha