GMAT閱讀里的邏輯題是比較有特色的一類題型，一般來說，它的出題形式有增強(qiáng)或削弱結(jié)論，比如Which of the following, if true, would most weaken/ strengthen the author’s conclusion in lines …? 在極少的情況下，會(huì)考察為結(jié)論補(bǔ)充前提。今天雷哥GMAT培訓(xùn)就給大家講講在GMAT閱讀里面是難度相對較高的題型——邏輯題應(yīng)該如何突破吧！

在做邏輯題的時(shí)候，同學(xué)們一定要掌握一個(gè)原則，無論是增強(qiáng)結(jié)論還是削弱結(jié)論，都要回到文章中，尋找得到這個(gè)結(jié)論的前提或者相關(guān)信息，然后通過處理前提從而得到增強(qiáng)或者削弱結(jié)論的目的。閱讀里面的邏輯題與CR不同點(diǎn)就在于，我們需要下手增強(qiáng)和削弱的地方都是應(yīng)該從文中出發(fā)尋找，不需要自己補(bǔ)充額外的信息，這樣梳理就相對比較容易了。所以在最下策的情況下，如果實(shí)在不知道應(yīng)該怎么選，可以從選項(xiàng)出發(fā)，看哪個(gè)選項(xiàng)與文章內(nèi)容最相關(guān)，這個(gè)時(shí)候選這個(gè)選項(xiàng)，也是相對有把握一點(diǎn)。

舉個(gè)例子來看：

A small number of the forest species of lepidoptera (moths and butterflies, which exist as caterpillars during most of their life cycle) exhibit regularly recurring patterns of population growth and decline—such fluctuations in population are known as population cycles. Although many different variables influence population levels, a regular pattern such as a population cycle seems to imply a dominant, driving force. Identification of that driving force, however, has proved surprisingly elusive despite considerable research. The common approach of studying causes of population cycles by measuring the mortality caused by different agents, such as predatory birds or parasites, has been unproductive in the case of lepidoptera. Moreover, population ecologists' attempts to alter cycles by changing the caterpillars’ habitat and by reducing caterpillar populations have not succeeded. In short, the evidence implies that these insect populations, if not self-regulating, may at least be regulated by an agent more intimately connected with the insect than are predatory birds or parasites.

這是一篇GMAT閱讀的第一段，針對這段考了一個(gè)邏輯題：

Which of the following, if true, would most weaken the author’s conclusion in lines?“In short,?…?than are predatory birds or parasites.”?

(A)New research reveals that the number of species of birds and parasites that prey on Lepidoptera has dropped significantly in recent years.

(B)New experiments in which the habitats of lepidoptera are altered in previously untried ways result in the shortening of lepidoptera population cycles.?

(C)Recent experiments have revealed that the nuclear polyhedrosis virus is present in a number of predators and parasites of lepidoptera.

(D)Differences among the habitats of Lepidoptera species make it difficult to assess the effects of weather on lepidoptera population cycles.

(E)Viral disease is typically observed in a large proportion of the lepidoptera population.

這道題問怎么樣能削弱段中的最后一句話，我們先回到文中找到這句話，里面有一個(gè)非常關(guān)鍵的詞語In short，表明這句話是由上文得來的，得到的結(jié)論是有一個(gè)agent能影響種群周期，那么是怎么得到這個(gè)結(jié)論的呢？我們回到上文看一下。當(dāng)研究種群周期的影響因素的時(shí)候，文中指出common approach是unproductive，而且進(jìn)一步指出，population ecologists' attempts也是not succeeded。正是因?yàn)檫@兩個(gè)方法都不行，我們才得到有agent的影響。那么要削弱這句話，只要表明上文的其中一個(gè)方法是可行的，那么agent就不起作用了。這個(gè)時(shí)候來看看選項(xiàng)，A，討論的是birds and parasites的數(shù)量變化，但這個(gè)變化不能說明研究方法的有效性，無關(guān)排除。B，新的試驗(yàn)表明，以一種之前沒有嘗試過的方法改變棲息地，使得種群周期減少。這個(gè)選項(xiàng)影響了種群周期，而且棲息地是之前population ecologists的嘗試，那么這個(gè)嘗試有效了，也就不用agent了，可以削弱。C，討論的是NP virus數(shù)量很大，結(jié)合下文NP virus就是agent，那么自然不能削弱。D，討論的是天氣的影響，無關(guān)排除。E，Viral disease數(shù)量大，也是無關(guān)排除。所以這道題應(yīng)該要選B。

結(jié)合這個(gè)例子，同學(xué)們應(yīng)該有一定的體會(huì)，GMAT閱讀里的邏輯題在判斷選項(xiàng)的時(shí)候，應(yīng)該選擇與結(jié)論最相關(guān)的一項(xiàng)。無論是增強(qiáng)還是削弱在文中都能找到信息對應(yīng)，帶著這個(gè)思路做題，邏輯題也能很簡單了。

申請季將至，越來越多同學(xué)開始備考GMAT，雷哥GMAT培訓(xùn)祝大家早日出分！