新概念英语第四册课文

新概念英语第四册1Lesson1Wecanreadofthingsthathappened5,000yearsagointheNearEast,wherepeoplefirstlearnedtowrite.Buttherearesomepartsoftheworldwhereevennowpeoplecannotwrite.Theonlywaythattheycanpreservetheirhistoryistorecountitassagas--legendshandeddownfromonegenerationofstory-tellerstoanother.Theselegendsareusefulbecausetheycantellussomethingaboutmigrationsofpeoplewholivedlongago,butnonecouldwritedownwhattheydid.AnthropologistswonderedwheretheremoteancestorsofthePolynesianpeoplesnowlivinginthePacificIslandscamefrom.ThesagasofthesepeopleexplainthatsomeofthemcamefromIndonesiaabout2,000yearsago.Butthefirstpeoplewhowerelikeourselveslivedsolongagothateventheirsagas,iftheyhadany,areforgotten.Soarchaeologistshaveneitherhistorynorlegendstohelpthemtofindoutwherethefirst'modernmen'camefrom.Fortunately,however,ancientmenmadetoolsofstone,especiallyflint,becausethisiseasiertoshapethanotherkinds.Theymayalsohaveusedwoodandskins,butthesehaverottedaway.Stonedoesnotdecay,andsothetoolsoflongagohaveremainedwheneventhebonesofthemenwhomadethemhavedisappearedwithouttrace.Lesson2Why,youmaywonder,shouldspidersbeourfriends?Becausetheydestroysomanyinsects,andinsectsincludesomeofthegreatestenemiesofthehumanrace.Insectswouldmakeitimpossibleforustoliveintheworld;theywoulddevourallourcropsandkillourflocksandherds,ifitwerenotfortheprotectionwegetfrominsect-eatinganimals.Weowealottothebirdsandbeastswhoeatinsectsbutallofthemputtogetherkillonlyafractionofthenumberdestroyedbyspiders.Moreover,unlikesomeoftheotherinsecteaters,spidersneverdotheleastharmtousorourbelongings.Spidersarenotinsects,asmanypeoplethink,norevennearlyrelatedtothem.Onecantellthedifferencealmostataglanceforaspideralwayshaseightlegsandaninsectnevermorethansix.Howmanyspidersareengagedinthisworkonourbehalf?OneauthorityonspidersmadeacensusofthespidersinagrassfieldinthesouthofEngland,andheestimatedthatthereweremorethan2,250,000inoneacre,thatissomethinglike6,000,000spidersofdifferentkindsonafootballpitch.Spidersarebusyforatleasthalftheyearinkillinginsects.Itisimpossibletomakemorethanthewildestguessathowmanytheykill,buttheyarehungrycreatures,notcontentwithonlythreemealsaday.IthasbeenestimatedthattheweightofalltheinsectsdestroyedbyspidersinBritaininoneyearwouldbegreaterthanthetotalweightofallthehumanbeingsinthecountry.Lesson3Modernalpiniststrytoclimbmountainsbyaroutewhichwillgivethemgoodsport,andthemoredifficultitis,themorehighlyitisregarded.Inthepioneeringdays,however,thiswasnotthecaseatall.Theearlyclimberswerelookingfortheeasiestwaytothetopbecausethesummitwastheprizetheysought,especiallyifithadneverbeenattainedbefore.Itistruethatduringtheir新概念英语第四册2explorationstheyoftenfaceddifficultiesanddangersofthemostperilousnature,equippedinamannerwhichwouldmakeamodernclimbershudderatthethought,buttheydidnotgooutoftheirwaytocourtsuchexcitement.Theyhadasingleaim,asolitarygoal--thetop!Itishardforustorealizenowadayshowdifficultitwasforthepioneers.ExceptforoneortwoplacessuchasZermattandChamonix,whichhadrapidlybecomepopular,Alpinevillagestendedtobeimpoverishedsettlementscutofffromcivilizationbythehighmountains.Suchinnsastherewereweregenerallydirtyandflea-ridden;thefoodsimplylocalcheeseaccompaniedbybreadoftentwelvemonthsold,allwasheddownwithcoarsewine.Oftenavalleyboastednoinnatall,andclimbersfoundshelterwherevertheycould--sometimeswiththelocalpriest(whowasusuallyaspoorashisparishioners),sometimeswithshepherdsorcheese-makers.Invariablythebackgroundwasthesame:dirtandpoverty,andveryuncomfortable.Formenaccustomedtoeatingseven-coursedinnersandsleepingbetweenfinelinensheetsathome,thechangetotheAlpsmusthavebeenveryhardindeed.Lesson4IntheSovietUnionseveralcaseshavebeenreportedrecentlyofpeoplewhocanreadanddetectcolourswiththeirfingers,andevenseethroughsoliddoorsandwalls.Onecaseconcernsan'eleven-year-oldschoolgirl,VeraPetrova,whohasnormalvisionbutwhocanalsoperceivethingswithdifferentpartsofherskin,andthroughsolidwalls.Thisabilitywasfirstnoticedbyherfather.Onedayshecameintohisofficeandhappenedtoputherhandsonthedoorofalockedsafe.Suddenlysheaskedherfatherwhyhekeptsomanyoldnewspaperslockedawaythere,andevendescribedthewaytheyweredoneupinbundles.Vera'scurioustalentwasbroughttothenoticeofascientificresearchinstituteinthetownofUIyanovsk,nearwhereshelives,andinAprilshewasgivenaseriesoftestsbyaspecialcommissionoftheMinistryofHealthoftheRussianFederalRepublic.Duringthesetestsshewasabletoreadanewspaperthroughanopaquescreenand,strangerstill,bymovingherelbowoverachild'sgameofLottoshewasabletodescribethefiguresandcoloursprintedonit;and,inanotherinstance,wearingstockingsandslippers,tomakeoutwithherfoottheoutlinesandcoloursofapicturehiddenunderacarpet.Otherexperimentsshowedthatherkneesandshouldershadasimilarsensitivity.DuringallthesetestsVerawasblindfold;and,indeed,exceptwhenblindfoldshelackedtheabilitytoperceivethingswithherskin.Itwasalsofoundthatalthoughshecouldperceivethingswithherfingersthisabilityceasedthemomentherhandswerewet.Lesson5ThegorillaissomethingofaparadoxintheAfricanscene.Onethinksoneknowshimverywell.Forahundredyearsor