加拿大研究生考試GRE閱讀經(jīng)典邏輯題分析

熟悉論證關(guān)系、熟練判斷論點(diǎn)論據(jù)是絕殺GRE閱讀不可或缺的手段。這需要系統(tǒng)的理論方法與大量的練習(xí)實(shí)踐共同作用。而下面這道題目在找到目標(biāo)結(jié)論這一步上就難倒了眾多同學(xué)。

我們一起來(lái)看看這個(gè)貌似有很多結(jié)論的邏輯削弱題到底應(yīng)該怎么去處理。GRE閱讀

Even after numerous products made with artificial sweeteners became available,sugar consumption per capita continued to rise.Now manufacturers are introducing fat-free versions of various foods that they claim have the taste and texture of the traditional high-fat versions.Even if the manufacturers'claim is true,given that the availability of sugar-free foods did not reduce sugar consumption,it is unlikely that the availability of these fat-free foods will reduce fat consumption.

Which of the following,if true,most seriously undermines the argument?

A.several kinds of fat substitute are available to manufacturers,each of which gives a noticeably different taste and texture to products that contain it.

B.the products made with artificial sweeteners did not taste like products made with sugar.

C.the foods brought out in sugar-free versions did not generally have reduced levels of fat,but many of the fat-free versions about to be introduced are low in sugar.

D.people who regularly consume products containing artificial sweeteners are more likely than others to consume fat-free foods.

E.not all foods containing fat can be produced in fat-free versions.

答案：B

解析：

B代糖吃起來(lái)并不像糖，因?yàn)榭谖队胁町?，所以糖原本的消耗沒(méi)有減少。所以當(dāng)代脂吃起來(lái)像高脂肪的時(shí)候，可能就降低了脂肪的消耗。能成功代替。

其他選項(xiàng)

A.代脂問(wèn)世，且嘗起來(lái)不一樣。反向選項(xiàng)，加強(qiáng)了結(jié)論。嘗起來(lái)不一樣，才會(huì)有人繼續(xù)買真脂肪。

C.低糖不一定低脂，但是低脂一定低糖。有區(qū)別，但是跟糖耗和脂耗都不相關(guān)。無(wú)關(guān)選項(xiàng)。

D.人工糖的消費(fèi)者比無(wú)脂肪的消費(fèi)者多。人工糖的消費(fèi)者多，不代表糖的消費(fèi)者比高脂的消費(fèi)者多。雖然有比較，但沒(méi)有達(dá)到目標(biāo)，無(wú)關(guān)選項(xiàng)。學(xué)在加拿大

E.并不是所有含脂肪的食物都可以改造成無(wú)脂的模式。

從題干可清晰知道此題為邏輯削弱題，需要針對(duì)文章結(jié)論進(jìn)行削弱。然而，難住很多的同學(xué)第一個(gè)問(wèn)題就是，這么多看起來(lái)像結(jié)論的地方，到底削弱誰(shuí)？終極目標(biāo)結(jié)論到底在哪里？

GRE閱讀沒(méi)有并列主要結(jié)論，出現(xiàn)多個(gè)結(jié)論時(shí)一定有主次之分，此時(shí)必然是針對(duì)主要結(jié)論進(jìn)行削弱。

加拿大研究生考試GRE閱讀經(jīng)典邏輯題分析

今天為大家提供判定主要結(jié)論的方式之一：將來(lái)時(shí)態(tài)是主要結(jié)論。順帶說(shuō)一句，只看位置前后去判斷主次結(jié)論風(fēng)險(xiǎn)極大。慎用！

因此，本文主要結(jié)論是：...it is unlikely that the availability of these fat-free foods will reduce fat consumption.

直接推翻結(jié)論，削弱之后目標(biāo)結(jié)論為：...it is unlikely that the availability of these fat-free foods will not reduce fat consumption.

此時(shí)出現(xiàn)第二個(gè)問(wèn)題，對(duì)于類比的理解是否準(zhǔn)確。類比論證是GRE閱讀中經(jīng)?？疾榈囊环N論證方式，其意義往往并非只停留在表面，需要我們深層挖掘。通過(guò)文章將可替代脂肪與代糖類比可知：代糖的出現(xiàn)不能讓糖的消耗降低，所以可替代脂肪的出現(xiàn)也不能導(dǎo)致脂肪消耗降低。