《综合英语5》阅读

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1、16)Flyingoveradesertareainanairplane,twoscientistslookeddownwithtrainedeyesattreesandbushes.Afteranhour'sflightoneofthescientistswroteinhisbook,'Lookhereforprobablemetal.Scientistswereflyingoveradesertorhillywastelandoramountainregioninordertosearchforintheground.a.goldb.silverc.metalsd.minera

2、ls2.Thestudyoftrees,branchesandrootsindicatesthat.Scientistsinanotherairplane,flyingoveramountainregion,sentamessagetootherscientistsontheground/Goldpossible/Walkingacrosshillyground,fourscientistsreported,Thisgroundshouldbesearchedformetals.1Fromanairplaneoverahillywastelandascientistsentback

3、byradiooneword/UraniunY.NoneofthescientistshadX-rayeyes:theyhadnomagicpowersforlookingdownbelowtheearthfssurface.Theyweremerelyputtingtouseoneofthenewestmethodsoflocationmineralsintheground—usingtreesandplantsassignsthatcertainmineralsmayliebeneaththegroundonwhichthetreesandplantsaregrowing.Th

4、isnewestmethodofsearchingformineralsisbasedonthefactthatmineralsdeepintheearthmayaffectthekindofbushesandtreesthatgrowonthesurface・AtWatsonBarCreek,abrooksixthousandfeethighinthemountainsofBritishColumbia,Canada,amineralsearchgroupgatheredbagsoftreeseeds.Boxedwerefilledwithsmallbanchesfromtetr

5、ees.Rootsweredugandputintoboxes.Eachbagandboxwascarefullymarked.Inascientificlaboratorythepartsoftheforesttreeswereburnedtoashesandtested.Eachsmallpartwasexaminedtolearnwhetherthereweremineralsinit.Studyoftheroots,branches,andseedsshowednosilver.Butthereweresmallamountsofgoldintherootsandalitt

6、lelessgoldinthebranchesandseeds・Theseedsgrowingnearesttothetreetrunkhadmoregoldthanthosegrowingontheendsofthebranches.Ifthetreeshadnotindicatedthattherewasgoldintheground,thescientistswouldnothavespentmoneytopayfordiggingintothedeeper.Theydiddigandfoundmorefoldbelow.Theydugdeeper.Theyfoundlarg

7、equantitiesofgold.a.therewerelargeramountsofgoldinthebranchesthanintheseeds.b.thereweresmallamountsofgoldintherootsthaninthebranchesc.therewerelargeramountsofgoldintheseedsgrowingnearesttothetreetrunkthanseedsgrowingontheendsofbranches・