揭秘托福阅读目的题－是不是选provide example的选项就OK了
口说无凭，先来看真题!
Paragraph 3: In 1831 when Smith was finally recognized by the Geological Society of London as the "father of English geology", was not only for his maps but also for something even more important. Ever since people had begun to catalog the strata in particular outcrops, there had been the hope that these could somehow be used to calculate geological time. But as more and more accumulations of strata were cataloged in more and more places, it became clear that the sequences of rocks sometimes differed from region to region and that no rock type was ever going to become a reliable time marker throughout the world. Even without the problem of regional differences, rocks present a difficulty as unique time markers .Quartz is quartz-a silicon ion surrounded by four oxygen ions-there's no difference at all between two-million-year-old Pleistocene quartz and Cambrian quartz created over 500 million years ago.
Why does the author use the phrase "Quartz is quartz"?
a)○ To describe how the differences between Pleistocene and Cambrian quartz reveal information about dating rocks
b)○ To point out that the chemical composition of quartz makes it more difficult to date than other rocks
c)○ To provide an example of how regional differences in rock sequences can make a particular rock difficult to date
d)○ To explain that rocks are difficult to use for dating because their chemical compositions always remain the same over time
题干问"作者为什么使用石英就是石英"这个短语?回原文我们看到考点句"Quartz is quartz-a silicon ion surrounded by four oxygen ions-there's no difference at all between two-million-year-old Pleistocene quartz and Cambrian quartz created over 500 million years ago. (石英就是石英，在两百万年前更新世时代的石英和五亿年前寒武纪时代的石英没有差别.)"只是一个客观事实信息的表述。根据目的题解题思路，我们需要寻找作者在表述这一事实信息背后的意图。因为考点句是本段最后一句，所以我们向前看"Even without the problem of regional differences, rocks present a difficulty as unique time markers (即使没有地区差异的问题，石头作为与众不同的时间标记也是有问题的)."除去让步信息"Even without the problem of regional differences(即使没有地区差异的问题)"本句最主要想要说明rocks present a difficulty as unique time markers(石头作为与众不同的时间标记也是有问题的)，联系下一句含有"石英"的句子，石英作为石头的一种，在不同时间年代中性质特征都一样，证明了石头作为与众不同时间标记存在问题。理清思路之后，我们来看选项：
A.描述在更新世和寒武纪中形成石头在揭露确定地质时间方面的差异
B.指出石英的化学成分使它比别的石头更难确定地质时间
C.举例证明地区差异使某种特定的石头特别难确定地质时间举例子
D.解释石头只所以难确定地质时间是因为它们的化学成分一直保持一致
选项D与我们上面分析一致，是正确答案。但从学生实际答题来看，因为C选项包含了目的题考查的核心思路(provide example)特别容易让大家选错。
那是不是在说含provide example的选项就是不对的?答案也同样的NO!!! 该类例题在真题中比比皆是，我们随便揪出来一道看看：
Paragraph6: A third fossil formation containing both soft-bodied and hard-bodied animals provides evidence of the result of the Cambrian explosion. This fossil formation, called the Burgess Shale, is in Yoho National Park in the Canadian Rocky Mountains of British Columbia. Shortly after the Cambrian explosion, mud slides rapidly buried thousands of marine animals under conditions that favored fossilization. These fossil beds provide evidence of about 32 modern animal groups, plus about 20 other animal body forms that are so different from any modern animals that they cannot be assigned to any one of the modern groups. Theseunassignable animals include a large swimming predator called Anomalocaris and a soft-bodied animal called Wiwaxia, which ate detritus or algae. The Burgess Shale formation also has fossils of many extinct representatives of modern animal groups. For example, a well-known Burgess Shale animal called Sidneyia is a representative of a previously unknown group of arthropods (a category of animals that includes insects, spiders, mites, and crabs).
Why does the author mention Anomalocans and Wiwaxia?
a)To contrast predators with animals that eat plants such as algae
b)To question the effects of rapid mud slides on fossilization
c)To suggest that much is still unknown about animals found in the Burgess Shale
d)To provide examples of fossils that cannot be assigned to a modern animal group
e)题目问作者为什么提到Anomalocans and Wiwaxia?我们看到考点句 "These unassignable animals include a large swimming predator called Anomalocaris and a soft-bodied animal called Wiwaxia, which ate detritus or algae." 中include表明了后面提到的Anomalocaris及Wiwaxia是These unassignable animals的例子。利用指代关系还原指向考点句上一句"modern animals that they cannot be assigned to any one of the modern groups(不可能被分类到任何一种现代动物族群中的动物群体)"所以Anomalocans and Wiwaxia是不可被分类到现代动物族群中的动物群体的例子。根据以上分析，该题应该选择D (To provide examples of fossils that cannot be assigned to a modern animal group 为不能被分类到现代动物族群中的化石提供例子)。
根据以上两道真题的分析，大家可以得出结论：目的题作答过程中最应该注意的是为做题提供的事实信息寻找背后的观点，而不是根据选项是否有"provide example"这样的表达来确定正确答案。
