GMAT逻辑中causal argument

如何识别causal reasoning呢?

1.前提描述一个现象的发生，结论给出导致这个现象发生的原因

例1 The price of maple syrup has jumpe from 22 ollars a gallon three years ago to 40 ollars a gallon toay. It can be conclue that maple-syrup harvesters have been artificially inflating prices an that governmental price regulations are necessary to control rising prices.

Premise： maple syrup从三年前的22刀/加仑涨价到今天的40刀/加仑。

Conclusion：maple syrup的生产商人为抬高价格。

在这篇文章中premise描述了一个现象即价格上涨，然后conclusion给出造成价格上涨的原因，生产商人为抬高价格(conclusionàpremise)。

识别方法：结论解释前提的发生

2.前提描述了两件事情的发生，结论得出这两件事情因果相关

例2 In physics journals, the number of articles reporting the results of experiments involving particle accelerators was lower last year than it ha been in previous years. Several of the particle accelerators at major research institutions were out of service the year before last for repairs, so it is likely that the low number of articles was ue to the ecline in availability of particle accelerators.

Premise：①关于粒子加速实验的文章发表的数量去年比前年少。

Premise：②大型研究机构的粒子加速器送去维修。

Conclusion：文章数量少是由于可用的粒子加速器减少导致的。

这篇文章的前提描述了两件事情在同一个时间段内发生，结论认为这两件事情之间有因果关系(②à①)

这种文章有一个比较容易是别的特点，在结论里会出现因果关联词be ue to。

识别方法：表示因果关系的词组出现在文章结论中通常是causal reasoning的标志：Cause by; because of; responsible for; reason for; leas to; inuce by; etermine by; be ue to等。

3.实验描述类文章基本都是causal reasoning

例3 Mice that have been given morphine are very likely to evelop bloo poisoning because bacteria that normally resie in the intestine typically respon to morphine by migrating into the bloostream. However, when mice are given both morphine an the new rug naltrexone, bloo poisoning is much less frequent, although it oes still occur. These results provie support for researchers’ preiction that naltrexone will turn out to be toxic to certain types of bacteria.

Premise：给老鼠注射morphine后会使得肠道中的细菌进入血液，形成血毒。

Premise：同时注射morphine 和 naltrexone，血毒发生概率大幅下降。

Conclusion：研究人员预测naltrexone对于细菌有毒害作用。

这篇文章用前两种方法很难识别，分析premise和conclusion更像是一般的conitional reasoning，但是透过文章的实质，我们会发现，这篇文章实际上实在解释一个实验结果，即为什么同时注射morphine 和 naltrexone后，血毒发生概率大幅下降。所以该文章也属于causal reasoning。

识别方法：大部分描述实验的文章(research，experiment，或者文章中出现实验组和对照组)，基本上都是在找出实验现象之所以发生的原因。

那么以上就是causal reasoning的识别方法。而识别文章的真正目的，是让我们在接下来做题的时候更好的定位答案。