新概念第四册打印版-课文

1Lesson1FindingfossilmanWecanreadofthingsthathappened5,000yearsagointheNearEast,wherepeoplefirstlearnedtowrite.Buttherearesomepartsofthewordwhereevennowpeoplecannotwrite.Theonlywaythattheycanpreservetheirhistoryistorecountitassagas--legendshandeddownfromonegenerationofanother.Theselegendsareusefulbecausetheycantellussomethingaboutmigrationsofpeoplewholivedlongago,butnonecouldwritedownwhattheydid.AnthropologistswonderedwheretheremoteancestorsofthePolynesianpeoplesnowlivinginthePacificIslandscamefrom.ThesagasofthesepeopleexplainthatsomeofthemcamefromIndonesiaabout2,000yearsago.Butthefirstpeoplewhowerelikeourselveslivedsolongagothateventheirsagas,iftheyhadany,areforgotten.Soarchaeologistshaveneitherhistorynorlegendstohelpthemtofindoutwherethefirst'modernmen'camefrom.Fortunately,however,ancientmenmadetoolsofstone,especiallyflint,becausethisiseasiertoshapethanotherkinds.Theymayalsohaveusedwoodandskins,butthesehaverottedaway.Stonedoesnotdecay,andsothetoolsoflongagohaveremainedwheneventhebonesofthemenwhomadethemhavedisappearedwithouttrace.Lesson2SparethatspiderWhy,youmaywonder,shouldspidersbeourfriends?Becausetheydestroysomanyinsects,andinsectsincludesomeofthegreatestenemiesofthehumanrace.Insectswouldmakeitimpossibleforustoliveintheworld;theywoulddevourallourcropsandkillourflocksandherds,ifitwerenotfortheprotectionwegetfrominsect-eatinganimals.Weowealottothebirdsandbeastswhoeatinsectsbutallofthemputtogetherkillonlyafractionofthenumberdestroyedbyspiders.Moreover,unlikesomeoftheotherinsecteaters,spidersneverdotheharmtousorourbelongings.Spidersarenotinsects,asmanypeoplethink,norevennearlyrelatedtothem.Onecantellthedifferencealmostataglance,foraspideralwayshaseightlegsandinsectnevermorethansix.Howmanyspidersareengagedinthisworknoourbehalf?OneauthorityonspidersmadeacensusofthespidersingrassfieldinthesouthofEngland,andheestimatedthatthereweremorethan2,250,000inoneacre;thatissomethinglike6,000,000spidersofdifferentkindsonafootballpitch.Spidersarebusyforatleasthalftheyearinkillinginsects.Itisimpossibletomakemorethanthewildestguessathowmanytheykill,buttheyarehungrycreatures,notcontentwithonlythreemealsaday.IthasbeenestimatedthattheweightofalltheinsectsdestroyedbyspidersinBritaininoneyearwouldbegreaterthanthetotalweightofallthehumanbeingsinthecountry.Lesson3MatterhornmanModernalpiniststrytoclimbmountainsbyaroutewhichwillgivethemgoodsport,andthemoredifficultitis,themorehighlyitisregarded.Inthepioneeringdays,however,thiswasnotthecaseatall.Theearlyclimberswerelookingfortheeasiestwaytothetop,becausethesummitwastheprizetheysought,especiallyifitandneverbeenattainedbefore.Itistruethatduringtheirexplorationstheyoftenfaceddifficultiesanddangersofthemostperilousnature,equippedinamannerwithwouldmakeamodernclimbershudderatthethought,buttheydidnotgooutoftheirwaytocourtsuchexcitement.Theyhadasingleaim,asolitarygoal--thetop!Itishardforustorealizenowadayshowdifficultitwasforthepioneers.ExceptforoneortwoplacessuchasZermattandChamonix,whichhadrapidlybecomepopular,Alpinevillagetendedtobeimpoverishedsettlementscutofffromcivilizationbythehighmountains.Suchinnsasthereweregenerallydirtyandflea-ridden;thefoodsimplylocalcheeseaccompaniedbybreadoftentwelvemonthsold,allwasheddownwith2coarsewine.Oftenavalleyboastednoinnatall,andclimbersfoundshelterwherevertheycould--sometimeswiththelocalpriest(whowasusuallyaspoorashisparishioners),sometimeswithshepherdsorcheese-makers.Invariablythebackgroundwasthesame:dirtandpoverty,andveryuncomfortable.Formenaccustomedtoeatingseven-coursedinnersandsleepingbetweenfinelinensheetsathome,thechangetotheAlpsmusthaveveryhardindeed.Lesson4SeeinghandsSeveralcaseshavebeenreportedinRussiarecentlyofpeoplewhocandetectcolourswiththeirfingers,andevenseethroughsolidandwalls.Onecaseconcernsandeleven-year-oldschoolgirl,VeraPetrova,whohasnormalvisionbutwhocanalsoperceivethingswithdifferentpartsofherskin,andthroughsolidwalls.Thisabilitywasfirstnoticedbyherfather.Onedayshecameintohisofficeandhappenedtoputherhandsonthedoorofalockedsafe.Suddenlysheaskedherfatherwhyhekeptsomanyoldnewspaperslockedawaythere,andevendescribedthewaytheyweredoneupinbundles.Vera'scurioustalentwasbroughttothenoticeofascientificresearchinstituteinthetownofUlyanovsk,nearwhereshelives,andinAprilshewasgivenaseriesoftestsbyaspecialcommissionoftheMinistryofHealthoftheRussianFederalRepublic.Duringthesetestsshewasabletoreadanewspaperthroughanopaquescreenand,strangerstill,bymovingherelbowoverachild'sgameofLottoshewasabletodescribethefiguresandcoloursprintedonit;and,inanotherinstance,wearingstockingsandslippers,tomakeoutwithherfoottheoutlinesandcoloursofapicturehiddenunderacarpet.Otherexperimentsshowedthatherkneesandshouldershadasimilarsensitivity.DuringallthesetestsVerawasblindfold;and,indeed,exceptwhenblindfoldshelackedtheabilitytoperceivethingswithherskin.Itwasalsofoundthatalthoughshecouldperceivethingswithherfingersthisabilityceasedthemomentherhandswerewet.Lesson5YouthPeoplearealwaystalkingabout'theproblemofyouth'.Ifthereisone--whichItakeleavetodoubt--thenitisolderpeople