[托福培训]托福阅读之句子插入题详解

　　[托福培训]托福阅读之句子插入题详解托福阅读中，有一类题绝对是必考题，那就是句子插入题，虽然题量不多，但基本上每篇文章内都会出现。那么做这类题有什么方法和技巧呢？下面朗阁托福培训的将就句子插入题的解题步骤做出详细的说明。

　　解题步骤与解题要点

　　Ø阅读并分析待插入的句子，找出其中的线索词；

　　Ø从个小黑方块前一句开始读，逐一代入进行验证；

　　Ø插入句必须满足前后两条线索，先前再后。（先用前线索再看后线索）

　　从此步骤中可以看出掌握线索词是解答此题的关键，那么线索词都有哪些？主要有两大类，指代线索和逻辑线索。

　　1.指代线索

　　(1).指代词(they,it,them)必然有所指代；指代词(this,these,their,other,another,such)后面若有名词短语，则向前寻找此名词短语或其同义改写。

　　例题1:

　　Paragraph4:Regularlyflowingriversandstreamsthatoriginatewithinaridlandsareknownasendogenous.Thesearegenerallyfedbygroundwatersprings,andmanyissuefromlimestonemassifs,suchastheAtlasMountainsinMorocco.Basalticrocksalsosupportsprings,notablyattheJabalAl-ArabontheJordan-Syriaborder.■Endogenousriversoftendonotreachtheseabutdrainintoinlandbasins,wherethewaterevaporatesorislostintheground.■Mostdesertstreambedsarenormallydry,buttheyoccasionallyreceivelargeflowsofwaterandsediment.■

　　Paragraph5:Desertscontainlargeamountsofgroundwaterwhencomparedtotheamountstheyholdinsurfacestoressuchaslakesandrivers.■Butonlyasmallfractionofgroundwaterentersthehydrologicalcyclefeedingtheflowsofstreams,maintaininglakelevels,andbeingrecharged(orrefilled)throughsurfaceflowsandrainwater.(TPO16WaterintheDesert)

　　12.Lookatthefoursquares[■]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.

　　Thesesuddenfloodsprovideimportantwatersuppliesbutcanalsobehighlydestructive.

　　Wherewouldthesentencebestfit?

　　解析：

　　1.分析黑体句，找到其中的线索词即为thesesuddenfloods,则要插入的方块前面必定要出现名词短语suddenfloods或是其同义改写。

　　2.从个小黑方块前一句开始读，寻找与线索词相吻合的信息。

　　3.在第三个方块前面出现了largeflowsofwaterandsediment（巨大的水流和沉积物），即为suddenfloods的同义替换，所以答案应当是第三个黑方块的位置。

　　例题2:

　　Paragraph4:Oneoftheouterplanets,Saturn,hasadensityofonly0.7thatofwater,whichmeansthatSaturnwouldfloatinwater.Variationsinthecompositionoftheplanetsarelargelyresponsibleforthedensitydifferences.■Thesubstancesthatmakeupbothgroupsofplanetsaredividedintothreegroupsgases,rocks,andicesbasedontheirmeltingpoints.■Theterrestrialplanetsaremostlyrocks:denserockyandmetallicmaterial,withminoramountsofgases.■TheJovianplanets,ontheotherhand,containalargepercentageofthegaseshydrogenandhelium,withvaryingamountsofices:mostlywater,ammonia,andmethaneices.■(TPO16PlanetsinOurSolarSystem)

　　12.Lookatthefoursquares[■]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.

　　Thisexplainstheirrelativelylowdensities.

　　Wherewouldthesentencebestfit?

　　解析：首先分析待插入的句子，涉及两个指代词，this和their,根据这两个指代词则能够推出前文一定要讲到某些密度较低的行星（即their所指代的），并且前面还要给出密度低的原因（即this所指代的）。然后阅读段落，发现段落中首先提到行星构成成分的不同会导致密度的差异，然后讲到类地行星(terrestrialplanets)主要由密度大的石头组成，然后提到类木行星(Jovianplanets)是由大量的气体组成的，所以正确答案应是第四个黑方块的位置。

　　(2).定冠词the+名词，用于重复上文提到的事物

　　例题1:

　　Paragraph3:Filmanalysisoftheinfant'sresponses,heartandrespirationratemonitors,andnonnutritivesuckingdevicesareusedaseffectivetoolsinunderstandinginfantperception.■Filmanalysispermitsresearcherstocarefullystudytheinfant'sresponsesoverandoverandinslowmotion.■Precisemeasurementscanbemadeofthelengthandfrequencyoftheinfant'sattentionbetweentwostimuli.■Heartandrespirationmonitorsprovidetheinvestigatorwiththenumberofheartbeatsorbreathstakenwhenanewstimulusispresented.■reasesinnonnutritivesuckingwerefirstusedasanassessmentmeasurebyresearchersin1969.

　　13.Lookatthefoursquares[■]thatindicatewherethefollowingsentencecouldbeaddedtothepassage.

　　Therepetitionallowsresearcherstoobservetheinfant'sbehavioruntiltheyreachagreementaboutthepresenceandthedegreeoftheinfant'sresponse.

　　Wherewouldthesentencebestfit?

　　解析：分析黑体句，找到线索词therepetition,根据规则前文中应出现repetition这个信息，从个小黑方块前一句开始分析，发现第二个黑方块前面出现了…overandoverandinslowmotion,识别出是repetition的同义改写，则答案即为第二个小黑方块位置。

　　例题2:

　　TheuniversalglobalwarmingattheendoftheIceAgehaddramaticeffectsontemperateregionsofAsia,Europe,andNorthAmerica.Icesheetsretreatedandsealevelsrose.■TheclimaticchangesinsouthwesternAsiaweremoresubtle,inthattheyinvolvedshiftsinmountainsnowlines,rainfallpatterns,andvegetationcover.■However,thesesamecyclesofchangehadmomentousimpactsonthesparsehumanpopulationsoftheregion.■AttheendoftheIceAge,nomorethanafewthousandforagerslivedalongtheeasternMediterraneancoast,intheJordanandEuphratesvalleys.Within2,000years,thehumanpopulationoftheregionnumberedinthetensofthousands,allasaresultofvillagelifeandfarming.■Thankstonewenvironmentalandarchaeologicaldiscoveries,wenowknowsomethingaboutthisremarkablechangeinlocallife.

　　13.Lookatthefoursquares[■]thatindicatewherethefollowingsentencecanbeaddedtothepassage.

　　Oneofthemajoreffectswastherapidgrowthofthehumanpopulationitself.

　　Wherewouldthesentencebestfit?

　　Clickonasquare[■]toinsertthesentenceinthepassage.

　　解析：分析待插入的句子，可以找到线索词themajoreffects,则推出前文中一定要提到effects或其同义替换，本题中还有一个后线索，后面的句子中应该要提到人口的迅速增长这个信息。阅读段落，发现thesesamecyclesofchangehadmomentousimpactsonthesparsehumanpopulationsoftheregion中impacts即为effects的同义替换，并且第三个黑方块后面的两句话都在详细论述人口从最初的几千人增加到上万人，所以前后都符合线索词，则正确答案为第三个黑方块。

　　2.逻辑线索

　　在逻辑线索中主要会出现以下几种情况：

　　(1).插入句中出现表结果的托福培训托福阅读句子插入题