#阅读求助帖#求助各位大神们一道简单的阅读

HarmanJUID：3821914

There have been numerous well-documented extinctions of indigenous species caused by the
introduction of non-indigenous predators and pathogens. However, surprisingly few extinctions of indigenous species can be attributed to competition from introduced species. For example, during the past 400 years, 4,000 plant species have been introduced into North America, and these nonindigenous plants currently account for nearly 20 percent of North America’s plant species. Yet no evidence exists that any indigenous North American plant species became extinct as a result of competition from new species could mean that such extinctions take longer to occur than scientists initially believed or, alternatively, that extinctions are rarely caused by competition from nonindigenous species.

1、The passage is concerned primarily with

A.pointing out that a particular type of species extinction is rarely known to occur.


B.proposing a possible explanation for conflicting data about a particular type of species extinction.


C.resolving a debate about the frequency of a particular type of species extinction.


D.comparing two theories regarding possible causes of a particular type of species extinction.


E.refuting a proposed explanation for the increasingly rare occurrence of a particular type of species extinction.

为何答案是A呢。。。。网上也有说是B的，做的时候也是选了B，求各位大神解答。。。。

onelittlemajiaUID：3795546

A
这道题我以前做的时候也搞不懂，隔了一段时间现在再看明白了。
文章第一句：大量文献记载因为外来物种导致本土物种灭绝。
第二句转折：但是，很少的灭绝是因为与引进物种的竞争。
后面都是在驳斥 "competition from introduced species 导致 extinction”
最后一句：没有证据证明“与引进物种的竞争导致本土物种灭亡” ，说明要么这中灭亡要花很长很长的时间，要么根本“extinctions are rarely caused by competition from nonindigenous species”

所以文章重点是在说extinctions caused by competition from nonindigenous species这一观点不成立
也就是A, "a particular type of species extinction"指的就是“extinctions caused by competition from nonindigenous species”

AimeeGongUID：3783513

同意楼上，
此为驳斥型文章，B选项明显对应的是解释型文章，这两种类型在GRE阅读里面的区别尤其就体现在主旨目的题上，楼主可以找类似的文章总结感受一下

从做题技巧上看的话，确定文章类型之后，B选项连混淆选项都不是，可以直接排除哈