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D Beyondtwoorthreedays，theworld’sbestweatherforecastsaredoubtful,andbeyondsixorseventheyareworthless. TheButterflyEffectisthereason.Forsmallpiecesofweather—toaglobalforecaster，smallcanmeanthunder—stormsandblizzards（暴风雪）—anypredictionbecomesworserapidly.Errorsanduncertaintiesincrease，fromdustdevilsandstormsuptocontinent-sizeeddies（旋涡）thatonlysatellitescansee. Themodernweathermodelsworkwithnet-likepointssixtymilesapart，andevenso，somestartingdatahavetobeguessed，sincegroundstationsandsatellitescannotseeeverywhere.Butsupposetheearthcouldbecoveredwithsensorsplacedonefootapart，risingatone-footintervalsallthewaytothetopoftheatmosphere.Supposeeverysensorgivesperfectlyaccuratereadingsoftemperature，pressure，humidity（温度）,andanyotherdataaweathermanwouldwant.Exactlyatnoonapowerfulcomputertakesallthedataandcalculateswhatwillhappenateachpointat12.01,then12.02，then12.03…thecomputerwillstillbeunabletopredictwhetherPrincetonwillhavesunorrainonemonthaway.Atnoonthespacesbetweenthesensorswillhidefluctuations（波动）thatthecomputerwillnotknowabout.By12.01，thosefluctuationswillalreadyhavecreatedsmallerrorsonefootaway.Soontheerrorswillhaveaddedtotheten-footscale，andsoonuptothesizeoftheglobe. 63．Aweatherforecast____________intheworld. A．isreliablewithinoneortwodays B．isdoubtfulbeyond24hours C．becomesuselessbeyondtwoorthreedays D．isstillworthwhileinsevendays 64．Usuallythereisaweathersub-station____________. A．ineverycityB．every60miles C．betweentwocities D．everyonefoot 65．Whichofthefollowingstatementsistrue？ A．Peoplehavenotplacedsensorsonefootapartintheatmosphere. B．Scientistshavealreadyputsensorsonefootapartintheworld. C．Everysensorgivesperfectlyaccuratedataaweathermanwants. D．Groundweatherstationsandsatellitescanseeeveryplaceonearth. 66．Ourcomputerwillnotbeabletoknowaboutfluctuationsbecause____________. A．thesensorsarenotgoodenough B．theyarehiddenbythespacesbetweenthesensors C．they 田梅回答：
小题1:A小题2:B小题3:A小题4:B
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