资源描述：
《新概念英语第四册课文》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、Lesson1FindingfossilmanWecanreadofthingsthathappened5,000yearsagointheNearEast,wherepeoplefirstlearnedtowrite.Buttherearesomepartsofthewordwhereevennowpeoplecannotwrite.Theonlywaythattheycanpreservetheirhistoryistorecountitassagas--legendshandeddownfromonegenerationofanother.T
2、heselegendsareusefulbecausetheycantellussomethingaboutmigrationsofpeoplewholivedlongago,butnonecouldwritedownwhattheydid.AnthropologistswonderedwheretheremoteancestorsofthePolynesianpeoplesnowlivinginthePacificIslandscamefrom.ThesagasofthesepeopleexplainthatsomeofthemcamefromI
3、ndonesiaabout2,000yearsago.Butthefirstpeoplewhowerelikeourselveslivedsolongagothateventheirsagas,iftheyhadany,areforgotten.Soarchaeologistshaveneitherhistorynorlegendstohelpthemtofindoutwherethefirst'modernmen'camefrom.Fortunately,however,ancientmenmadetoolsofstone,especiallyf
4、lint,becausethisiseasiertoshapethanotherkinds.Theymayalsohaveusedwoodandskins,butthesehaverottedaway.Stonedoesnotdecay,andsothetoolsoflongagohaveremainedwheneventhebonesofthemenwhomadethemhavedisappearedwithouttrace.Lesson2SparethatspiderWhy,youmaywonder,shouldspidersbeourfrie
5、nds?Becausetheydestroysomanyinsects,andinsectsincludesomeofthegreatestenemiesofthehumanrace.Insectswouldmakeitimpossibleforustoliveintheworld;theywoulddevourallourcropsandkillourflocksandherds,ifitwerenotfortheprotectionwegetfrominsect-eatinganimals.Weowealottothebirdsandbeast
6、swhoeatinsectsbutallofthemputtogetherkillonlyafractionofthenumberdestroyedbyspiders.Moreover,unlikesomeoftheotherinsecteaters,spidersneverdotheharmtousorourbelongings.Spidersarenotinsects,asmanypeoplethink,norevennearlyrelatedtothem.Onecantellthedifferencealmostataglance,foras
7、pideralwayshaseightlegsandinsectnevermorethansix.Howmanyspidersareengagedinthisworknoourbehalf?OneauthorityonspidersmadeacensusofthespidersingrassfieldinthesouthofEngland,andheestimatedthatthereweremorethan2,250,000inoneacre;thatissomethinglike6,000,000spidersofdifferentkindso
8、nafootballpitch.Spidersarebusyforatleasthalftheyearinkillingi
