托福阅读辅导-老托福阅读真题及答案passage11.docx

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1、托福浏览辅导:老托福浏览真题及答案passage11托福浏览辅导:老托福浏览真题及答案passage11为了帮助大家备考托福浏览，练习更多浏览题目。提高浏览水平，下面我给大家带来托福浏览辅导:老托福浏览真题及答案passage11，希望对大家有所帮助!老托福浏览文本passage11Plantsaresubjecttoattackandinfectionbyaremarkablevarietyofsymbioticspeciesandhaveevolvedadiversearrayofmechanismsdesignedtofrustratethepotentialcolonists.Thes

2、ecanbedividedintopreformedorpassivedefensemechanismsandinducibleoractivesystems.Passiveplantdefensecomprisesphysicalandchemicalbarriersthatprevententryofpathogens,suchasbacteria,orrendertissuesunpalatableortoxictotheinvader.Theexternalsurfacesofplants,inadditiontobeingcoveredbyanepidermisandawaxycut

3、icle,oftencarryspikyhairsknownastrichomes,whicheitherpreventfeedingbyinsectsormayevenpunctureandkillinsectlarvae.Othertrichomesarestickyandglandularandeffectivelytrapandimmobilizeinsects.Ifthephysicalbarriersoftheplantarebreached,thenpreformedchemicalsmayinhibitorkilltheintruder,andplanttissuesconta

4、inadiversearrayoftoxicorpotentiallytoxicsubstances,suchasresins,tannins,glycosides,andalkaloids,manyofwhicharehighlyeffectivedeterrentstoinsectsthatfeedonplants.ThesuccessoftheColoradobeetleininfestingpotatoes,forexample,seemstobecorrelatedwithitshightolerancetoalkaloidsthatnormallyrepelpotentialpes

5、ts.Otherpossiblechemicaldefenses,whilenotdirectlytoxictotheparasite,mayinhibitsomeessentialstepintheestablishmentofaparasiticrelationship.Forexample,glycoproteinsinplantcellwallsmayinactivateenzymesthatdegradecellwalls.Theseenzymesareoftenproducedbybacteriaandfungi.Activeplantdefensemechanismsarecom

6、parabletotheimmunesystemofvertebrateanimals,althoughthecellularandmolecularbasesarefundamentallydifferent.Both,however,aretriggeredinreactiontointrusion,implyingthatthehosthassomemeansofrecognizingthepresenceofaforeignorganism.Themostdramaticexampleofaninducibleplantdefensereactionisthehypersensitiv

7、eresponse.Inthehypersensitiveresponse,cellsundergorapidnecrosisthatis,theybecomediseasedanddieafterbeingpenetratedbyaparasite;theparasiteitselfsubsequentlyceasestogrowandisthereforerestrictedtooneorafewcellsaroundtheentrysite.Severaltheorieshavebeenputforwardtoexplainthebasisofhypersensitiveresistan

8、ce.老托福浏览题目passage111.Whatdoesthepassagemainlydiscuss?(A)Thesuccessofparasitesinresistingplantdefensemechanisms(B)Theoriesonactiveplantdefensemechanisms(C)Howplantdefensemechanismsfunction(D)Howtheimmunesystemofanimalsandthedefensemechanismsofplantsdiffer2.Thephrasesubjecttoinline1isclosestinmeaningt

9、o(A)susceptibleto(B)classifiedby(C)attractiveto(D)strengthenedby3.Thewordpunctureinline8isclosestinmeaningto(A)pierce(B)pinch(C)surround(D)cover.4.Thewordwhichinline12refersto(A)tissues(B)substances(C)barriers(D)insects5.WhichofthefollowingsubstancesdoestheauthormentionasNOTnecessarilybeingtoxictoth

10、eColoradobeetle?(A)resins(B)tannins(C)glycosides(D)alkaloids6.Whydoestheauthormentionglycoproteinsinline17?(A)tocompareplantdefensemechanismstotheimmunesystemofanimals(B)tointroducethediscussionofactivedefensemechanismsinplants(C)toillustratehowchemicalsfunctioninplantdefense(D)toemphasizetheimporta

11、nceofphysicalbarriersinplantdefense7.Theworddramaticinline23couldbestbereplacedby(A)striking(B)accurate(C)consistent(D)appealing8.Whereinthepassagedoestheauthordescribeanactiveplant-defensereaction?(A)Lines1-3(B)Lines4-6(C)Lines13-15(D)Lines24-279.Thepassagemostprobablycontinueswithadiscussionoftheo

12、rieson(A)thebasisofpassiveplantdefense(B)howchemicalsinhibitaparasiticrelationship.(C)howplantsproducetoxicchemicals(D)theprinciplesofthehypersensitiveresponse.老托福浏览答案passage11正确答案：CAABDCADD托福浏览技巧：词汇题应对方法为什么很多考生会对词汇题束手无措?一方面是由于考生的词汇量达不到，OG中词汇题的解释里有一句话，thereisno“listofwordsthatmustbetested.这句话就告诉考生死了

13、那条心去背所谓的大纲词汇，由于没有大纲，而考试中要考察到的单词可能是来自牛津字典或朗文字典中的任何一个单词，范围大的离谱;而另一方面则是由于有的考生没有学会从上下文或者从语法构造去猜想词义。由于OG中的解释还有一句awordmighthavemorethanonemeaning,butinthereadingpassage,onlyoneofthosemeaningisrelevant.所以很有可能考生在考试中所碰到的词汇并不是已经让人熟知的第一词义，而是要根据语境上下文推断出的第二词义甚至是第三词义，所以又对考生做题增加了难度。最可悲的是不仅文章中的单词意思不知道，连4个选项中的单词都有不认

14、识不熟悉的，这样的结果就只能是乱猜一气，听天由命全凭运气，当然考试结果也不会好。所以在此将给考生一点准备新托福浏览考试词汇题的建议和解题方法，希望能给考生攻克词汇题给予一些帮助。Tip:单词记忆单词记忆主要就是背单词。背单词是很多同学觉得非常痛苦的事情，经常会有学生来问药怎么背，背了一些又马上忘了另外一些。所以关于怎样去背单词，在这里有几点建议：1、利用零散的时间背单词。利用零散的时间背单词能够使用单词卡片。不过，为了保证效率，首先要确定哪些单词需要记忆。理论上，单词量越多越好。实际上，假如一味贪多，结果容易打疲惫战，而且效率低。所以，只记那些常考的核心词汇，而对于那些不太常用的学科名词、物质

15、名词一般加以忽略。2、进行高频率的重复，建议把重复的周期控制在7天以内。详细讲来，就是天天背100个单词，将过一遍这些单词的时间控制在半个小时以内，天天过4遍，第二天再过一遍前一天的。假如程度不是很好的同学能够压缩到50个左右，但尽量不要低于50个。单词材料能够找一些相关的新托福浏览词汇书，或者是以往考过的词汇题内容。把背单词和浏览相结合。广泛的浏览也是增加词汇量的一种方法，并且能够在浏览中加强对已经背过的单词的记忆。当一篇文章的生词量在5%左右的时候，这些生词的词义是可推的。所以我们在选择浏览材料的时候，应尽量将单词量控制在10%左右。单词过多，看不懂文章，太少又起不到提高的作用。相关材料能够上一些网站看，例如economist,nationalgeographic等等。托福浏览辅导:老托福浏览真题及答案passage11