◆◇五中选二的原则（theruleof2outof5）
逻辑推理题编写的一个基本原则是五个选项中的一个选项必须比其他的四个好。然而，正确选项的设计不能比其他四个选项明显地好以致问题的难度变得太小。这个原则使逻辑推理的命题人员陷入了左右为难的境地。如果一个问题让你去驳斥一个论证，那么一个选项必须能对段落的内在逻辑构成反对。这个选项将是“creditedresponse”。另外四个选项——迷惑选项distractors一定在某些方面不完美，但他们不能不一目了然，使问题变得ridiculouslyeasy。从某种意义上讲，preparingworkabledistractorsisactuallymoredifficultthanwritingthecreditedresponse。因此，通常五个选项中只有两个选项值得考虑（两者中仅仅在一个是对的）。另外三个选项，尽管有时与推理主题有点关联，但它们都有忽略了论点的推理结构。牢记：usuallyonlytwooftheanswerchoiceshaveanyrealmerit(onebeingthecorrectchoice).
总之，使得五个选项中只有一个难以排除，其他三个选项在很多情况下可能与问题目的无关，所以怎么样迅速排除三个选项是提高解题速度的关键。我在与ets负责命题的官员谈话时明显觉察到：编制逻辑推理题的最大痛苦与挑战不在于如何编制出一个非常像正确答案但又绝对不是正确答案的选项。实际上，有时五个选项中四个选项都编得极为荒谬，错得极为明显，只要阅读水平没问题，正确答案便跃然纸上。读者应在本书的大量归类讲解与训练中，培养挑选正确选项的感觉，进而找出错误选项特征。请看下面这个例子：
overthepastfifteenyears,thelargelyurbanizednortheasternunitedstateshasshownmoreandmo
retheinfluenceofthesouthwesternportionofthecountry.once,veryfewpeopleinnewyorkcityc
ouldbefoundsportingcowboybootsandstetsonhats,andnomajorradiostationboastedtwenty-f
our-hour-a-dayprogrammingofcountryandwesternmusic.thelatestdevelopmentistherapidproliferationo
frestaurantsservingchili,nachos,burritos,andothertex-mexdishes.thepassageabovemakeswhichofthefollowingassumptions?
(a)thelifestyleofpeopleinthenortheasthasbeenenrichedbytheinfluenceofthesouthwesternstates.
(b)mostresidentsofthesouthwesternstatesregularlyeatattex-mexrestaurants.
(c)overthelastfifteenyears,residentsofthesouthwesternunitedstateshaveincreasinglyadoptedlife
stylessimilartothoseofthenortheast.
(d)tex-mexdishesareanelementoftheregionalcuisineofthesouthwesternstates.
(e)peopleinthenortheasternunitedstateseatoutmorefrequentlythantheydidfifteenyearsago.
解析：本题的正确答案是（d）。theauthorclaimsthatthenortheasthasabsorbedelementsofthecultureofthesouthwestandpro
videsthreeexamples.atacitassumption(onewhichisnotproved)oftheargumentisthatacertainmodeofdress,akindofmusic,andatypeofcuisinearefoundintheso
uthwest.(d)articulatesthisassumption.
threeoftheremainingchoicesarereallyjust“flak.”theylackany6realplausibilityafterareasonablycarefulreading.theseare(a),(c),and(e).
(a)goesbeyondthescopeoftheinitialstatement.theauthorsimplystatesthatcertainculturalelement
softhesouthwesthavebeentransplantedtothenortheast,butnovaluejudgmentiscontainedinthepa
ragraphaboutthatprocess.
(c)reversesthecausallinkagedescribedbytheinitialstatement.accordingtotheauthor,thesouthwest
hasinfluencedthenortheast---notviceversa.
(e)goesbeyondthescopeoftheinitialstatement.nothingintheargumentsuggeststhatpeopleintheno
rtheastareeatingoutmorefrequentlythantheydidfifteenyearsago----onlythattheremoretex-mexrestaurantsintheregionthantherewerefifteenyearsago.
对大多数人而言，（b）最易误选。itatleasthasthemeritofbeingfairlycloselyconnectedtotheargumentintheinitialstatement.itmigh
tbetruethatpeopleinthesouthwestregularlypatronizethetex-mexrestaurants.that,however,isnotnecessarilyanassumptionoftheargument.allthatisrequired
fortheargumentisthatthereexistinthesouthwestsuchrestaurants---notthatresidentsofthatareapatronizethoserestaurantswithanyfrequency.
由上例可以看出，五个选项中的（a）、（c）和（e）的编写都非常荒谬，错得较为明显。“五中选二”的两个选项为（b）、（d），也就是说这五个选项中只有（b）、（d）值得考虑。（b）易误选。而正确答案只有一个，即（d）。