GRE阅览综合指导:63题新西方互联网讲堂总结(104)
新看法（对比特别，先显现新看法）Caffe***e, the stimulant *** ***ffee, has been call*** “the most widely us*** psychoactive substance on Earth.” Snyder, Daly and Bruns h**e recently（时辰状语，非常大概是新老看法比较型） propos*** that caffe***e affect beh**i*** by ***unter***g妨碍 the acti***ty *** the human bra*** of a naturally o***urr***g chem***al call*** adenos***e. Adenos***e n***mally depresses妨碍 ***uron fir***g神经激动 *** many areas of the bra***. It apparently does this by ***hibit***g（重点内容）妨碍 the release of ***urotransmitters, chem***als that carry ***rve impulses from o*** ***uron *** the ***xt. Like many other agents that affect ***uron fir***g, adenos***e must first b***d *** specif*** recep***rs on ***uronal ***mbra***s. There are at least two classes of these recep***rs, wh***h h**e been designat*** A1 and A2*7. Snyder et al (et al: abbr. (Lat) 和其余人，等人) propose that caffe***e, wh***h is structurally similar ****7B adenos***e, is able *** b***d *** both types of recep***rs, wh***h prevents妨碍 adenos***e from attach***g there and allows the ***urons *** fire m***e readily than they otherwise would.
老看法F*** many years（证实了是新老看法比较型）, caffe***e’s effects h**e been attribut*** *** its ***hibition妨碍 of the production of phosphodiesterase, an enzy*** that breaks down分化 the chem***al call*** cyc***c AMP. A number of ***urotransmitters exert their effects by first ***creas***g cyc***c AMP ***ncentrations *** target ***urons. Theref***e（论断）, prolong*** periods at the elevat*** ***ncentrations, as might be brought about by a phosphodiesterase ***hibi***r实在便是指咖啡豆因, ***uld lead *** a greater amount of ***uron fir***g and, ***nsequently, *** beh**i***al stimulation. But Snyder（老看法的形容中显现新看法的人名，用来批判老看法） et al 缘由一po***t out that the caffe***e ***ncentrations ********* *** ***hibit the production of phosphodiesterase *** the bra*** are much higher（对比句） than those that produce stimulation. 缘由2M***eover, other ***mpounds that block妨碍 phosphodiesterase’s acti***ty are not stimulants.
新看法的证明To buttress支撑（=supp***t） their case that caffe***e acts ***stead by prevent***g克制 adenos***e b***d***g, Snyder et al ***mpar*** the stimula***ry effects of a series of caffe***e derivatives with their abi***ty *** dislodge排挤 adenos***e from its recep***rs *** the bra***s of m***e. （做试验对比激励实力和排挤实力）“In ge***ral*8B,” they rep***t***（援用人物原话，是紧要出题点）, “the abi***ty of the ***mpounds *** ***mpete at the recep***rs ***rrelates with（正相联性） their abi***ty *** stimulate lo***motion *** the mouse; i.e., the higher their capacity *** b***d at the recep***rs, the higher their abi***ty *** stimulate lo***motion.” Theophyl******（与论断密切相连，篇幅小于5行，能够不看）, a close structural relative of caffe***e and the maj*** stimulant *** tea, was o*** of the most effective ***mpounds *** both regards.
新看法的破例状况及诠释There were so*** apparent exceptions*9A（不期望不显现的内容，间接跳去看IBMX这类术语） *** the ge***ral ***rrelation observ*** between adenos***e-recep***r b***d***g and stimulation. O*** of these was a ***mpound call*** 3-isobutyl-1-***thylxanth***e (IBMX), wh***h bound very well but actually depress***克制 mouse lo***motion. Snyder et al suggests that*9A this is not a maj*** stumb***ng block (stumb***ng block: n.停滞物, 绊脚石) *** their hypothesis. The problem is that the ***mpound has mix*** effects（全部疑问的回答） *** the bra****4A, a not unusual*4 o***urrence with psychoactive drugs. Even caffe***e, wh***h is ge***rally known o***y f*** its stimula***ry effects, displays this property, depress***g mouse lo***motion at very low ***ncentrations and stimulat***g it at higher o***s.
1. The primary purpose of the passage is ***中心议题题（写法性）
(A) discuss a plan f*** ***vestigation of a pheno***non that is not yet fully unders***od
(B) present two explanations of a pheno***non and re***ncile the differences between them
(C) summarize two the***ies and suggest a third the***y that over******s the problems en***unter*** *** the first two
(D) describe an a***ernative hypothesis and pro***de e***dence and argu***nts that supp***t it新老看法比较型（D）
(E) challenge the va***dity of a the***y by expos***g the ******nsistencies and ***ntrad***tions *** it
2. Wh***h of the follow***g, if true, would most weaken the the***y propos*** by Snyder et al?条理题（否决题）（太难了，不做需求）
(A) At very low ***ncentrations *** the human bra***, both caffe***e and theophyl****** tend *** h**e depressive rather than stimula***ry effects on human beh**i***.
(B) The abi***ty of caffe***e derivatives at very low ***ncentrations *** dislodge adenos***e from its recep***rs *** mouse bra***s ***rrelates well with their abi***ty *** stimulate mouse lo***motion at these low ***ncentrations.
(C) The ***ncentration of cyc***c AMP *** target ***urons *** the human bra*** that leads *** ***creas*** ***uron fir***g can be produc*** by several different phosphodiesterase ***hibi***rs *** addition *** caffe***e.
(D) The ***ncentration of caffe***e requir*** *** dislodge adenos***e from its recep***rs *** the human bra*** is much greater than the ***ncentration that produces beh**i***al stimulation *** humans.用S批评老看法的手法（D）
(E) The ***ncentration of IBMX requir*** *** dislodge adenos***e from its recep***rs *** mouse bra***s is much smaller than the ***ncentration that stimulates lo***motion *** the mouse.
3. A******d***g so Snyder et al, caffe***e differs from adenos***e *** that caffe***e
(A) stimulates beh**i*** *** the mouse and *** humans, whereas adenos***e stimulates beh**i*** *** humans o***y
(B) has mix*** effects *** the bra***, whereas adenos***e has o***y a stimula***ry effect
(C) ***creases cyc***c AMP ***ncentrations *** target ***urons, whereas adenos***e decreases such ***ncentrations
(D) permits release of ***urotransmitters when it is bound *** adenos***e recep***rs, whereas adenos***e ***hibits such release负相联联系（D）
(E) ***hibits both ***uron fir***g and the production of phosphodiesterase when there is a suff***ient ***ncentration *** the bra***, whereas adenos***e ***hibits o***y ***uron fir***g
4. In response *** experi***ntal resu***s ***ncern***g IBMX（最初一段）, Snyder et al ***ntend*** that it is not un***mmon*4 f*** psychoactive drugs *** h**e
(A) mix*** effects *** the bra****4A
(B) ***hibi***ry effects on enzy***s *** the bra***
(C) close structural relationships with caffe***e
(D) depressive effects on mouse lo***motion（A）
(E) the abi***ty *** dislodge caffe***e from recep***rs *** the bra***
5. The passage suggests that Snyder et al be***eve that if the older the***y ***ncern***g caffe***e’s effects were ***rrect, wh***h of the follow***g would h**e *** be the case?改良题（做法：找老看法的弱点——*老看法的双个缘由，取非；阐明双个缘故不可立）
I. All ***urotransmitters would ***crease the ***rt-term ***ncentration of cyc***c AMP *** target ***urons.
II. Substances other than caffe***e that ***hibit the production of phosphodiesterase would be stimulants.缘由2
III. All ***ncentration levels of caffe***e that are high enough *** produce stimulation would also ***hibit the production of phosphodiesterase.缘由一
(A) I o***y
(B) I and II o***y
(C) I and III o***y
(D) II and III o***y（D）
(E) I, II, and III
6. A******d***g *** Snyder et al, all of the follow***g ***mpounds can b***d *** specif*** recep***rs（两类：AD，咖啡豆因的类似物资） *** the bra*** EXCEPT
(A) IBMX
(B) caffe***e
(C) adenos***e
(D) theophyl******（E）
(E) phosphodiesterase
7. Snyder et al suggest that caffe***e’s abi***ty *** b***d *** A1 and A2 recep***rs*7 can be at least partially attribut*** ***（因果） wh***h of the follow***g?间接真相题
(A) The chem***al relationship between caffe***e and phosphodiesterase
(B) The structural relationship*7B between caffe***e and adenos***e
(C) The structural similarity between caffe***e and ***urotransmitters
(D) The abi***ty of caffe***e *** stimulate beh**i***（B）
(E) The natural o***urrence of caffe***e and adenos***e *** the bra***
8. The ***th*** quotes Snyder et al *** ******s 38-43 most probably *** ***der ***举例效用题（服侍于第3段——供应论据支撑新看法）
(A) reveal so*** of the assumptions underly***g their the***y
(B) summarize*8B a maj*** f***d***g of their experi***nts
(C) po***t out that their experi***nts were ***mit*** *** the mouse
(D) ***d***ate that their experi***nts resu****** o***y *** ge***ral ***rrelations（B）
(E) refute the objections made by supp***ters of the older the***y
9. The last paragraph of the passage perf***ms wh***h of the follow***g functions?
(A) Describes a dis***nfirm***g*9A experi***ntal resu*** and rep***ts the explanation*9A given by Snyder et al *** an attempt *** re***ncile this resu*** with their the***y.破例的状况及诠释
(B) Specifies the basis f*** the ***rrelation observ*** by Snyder et al and presents an explanation *** an attempt *** make the ***rrelation ***nsistent with the operation of psychoactive drugs other than caffe***e.
(C) Elab***ates the description of the ***rrelation observ*** by Snyder et al and suggests an additional explanation *** an attempt *** make the ***rrelation ***nsistent with the older the***y.
(D) Rep***ts ******nsistent experi***ntal data and describes the ***thod Snyder et al will use *** reanalyze this data.（A）
(E) Pro***des an example of the hypothesis propos*** by Snyder et al and relates this example *** caffe***e’s properties
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