小马托福阅读tpo7解析下载一

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1、小马托福阅读TPO7解析下载一小马托福阅读TPO7解析下载一。下面为大家整理了小马过河资料名师为大家解析的托福阅读TPO7，包括了TPO阅读解析及答案，希望对同学们备考托福阅读考试有一定的帮助。小马托福阅读TPO7解析下载TPO7-1-1原文：TheGeologicHistoryoftheMediterraneanIn1970geologistsKennethJ.HsuandWilliamB.F.RyanwerecollectingresearchdatawhileaboardtheoceanographicresearchvesselGlomarChallenger.Anobjectiveo

2、fthisparticularcruisewastoinvestigatetheflooroftheMediterraneanandtoresolvequestionsaboutitsgeologichistory.Onequestionwasrelatedtoevidencethattheinvertebratefauna(animalswithoutspines)oftheMediterraneanhadchangedabruptlyabout6millionyearsago.Mostoftheolderorganismswerenearlywipedout,althoughafewhar

3、dyspeciessurvived.AfewmanagedtomigrateintotheAtlantic.Somewhatlater,themigrantsreturned,bringingnewspecieswiththem.Whydidthenearextinctionandmigrationsoccur?AnothertaskfortheGlomarChallenger’sscientistswastotrytodeterminetheoriginofthedomelikemassesburieddeepbeneaththeMediterraneanseafloor.Thesestru

4、ctureshadbeendetectedyearsearlierbyecho-soundinginstruments,buttheyhadneverbeenpenetratedinthecourseofdrilling.WeretheysaltdomessuchasarecommonalongtheUnitedStatesGulfCoast,andifso,whyshouldtherehavebeensomuchsolidcrystallinesaltbeneaththeflooroftheMediterranean?Withquestionsuchastheseclearlybeforet

5、hem,thescientistsaboardtheGlomarChallengerprocessedtotheMediterraneantosearchfortheanswers.OnAugust23,1970,theyrecoveredasample.Thesampleconsistedofpebblesofhardenedsedimentthathadoncebeensoft,deep-seamud,aswellasgranulesofgypsumandfragmentsofvolcanicrock.Notasinglepebblewasfoundthatmighthaveindicat

6、edthatthepebblescamefromthenearbycontinent.Inthedaysfollowing,samplesofsolidgypsumwererepeatedlybroughtondeckasdrillingoperationspenetratedtheseafloor.Furthermore,thegypsumwasfoundtopossesspeculiaritiesofcompositionandstructurethatsuggestedithadformedondesertflats.Sedimentaboveandbelowthegypsumlayer

7、containedtinymarinefossils,indicatingopen-oceanconditions.Astheydrilledintothecentraland全国免费咨询电话：400-0123-267deepestpartoftheMediterraneanbasin,thescientiststooksolid,shiny,crystallinesaltfromthecoreb