雅思阅读List of Headings题型全面解析

我们就以本篇文章为例，选取其中具有代表性的题目给大家一一分析。

B Recent work on the problem of when people first entered the Americas is an example of the value of these new techniques. North-east Asia and Siberia have long been accepted as the launching ground for the first human colonisers of the New World. But was there one major wave of migration across the Bering Strait into the Americas, or several？ And when did this event, or events, take place？ In recent years, new clues have come from research into genetics, including the distribution of genetic markers in modern Native Americans.

VII Long-standing questions about prehistoric migration to America

Ix Questions about the causes of the prehistoric migration to America

大家会发现文章B段的第一句话读完之后并不能帮助我们解题。考生稍加观察就会发现在本段的后半部分有两个很明显的问句。很显然，能够很好的概括问句的词就是 questions.但是文章中关于questions的选项有VII 和IX两个。对于相似的选项大家可以通过进一步的比较找出区别。在这两个选项中，VII选项中包含了long-standing长期遗留的，而IX选项中有核心词 causes。仔细阅读文章中两个问句考生会发现原文并没有提及任何的原因。所以答案很显然是VII。

C An important project, led by the biological anthropologist Robert Williams, focused on the variants (called Gm allotypes) of one particular protein - immuneoglobin G- found in the fluid portion of human blood. All proteins 'drift', or produce variants, over the generations, and members of an interbreeding human population will share a set of such variants. Thus, by comparing the Gm allotypes of two different populations (e.g. two Indian tribes), one can establish their genetic 'distance', which itself can be calibrated to give an indication of the length of time since these populations last interbred.

x How analysis of blood-variants measures the closeness of the relationship between different

Sectionｃ中涉及的C落段落结构较为特殊。考生们很快会发现在文章的最后部分出现了thus这一表示总结的单词，那么这句话会是阅读的重点部分。最后一句话词汇难度较高，很多同学会很难读懂。在看不懂原文句子的具体意思时，大家可以采取寻找替换词的方式解题。例如本段的后半部和X选项中出现了 closeness和distance， relationship 和populations last interbred这对同意替换词。 那么答案选X也就顺理成章了。

E How far does other research support these conclusions Geneticist Douglas Wallace has studied mitochondrial DNA in blood samples from three widely separated Native American groups: Pima- Papago Indians in Arizona, Maya Indians on the Yucatan peninsula, Mexico, and Ticuna Indians in the Upper Amazon region of Brazil. As would have been predicted by Robert Williams's work, all three groups appear to be descended from the same ancestral (Paleo-lndian) population.

F There are two other kinds of research that have thrown some light on the origins of the Native American population; they involve the study of teeth and of languages. The biological anthropologist Christy Turner is an expert in the analysis of changing physical characteristics in human teeth. He argues that tooth crowns and roots have a high genetic component, minimally affected by environmental and other factors. Studies carried out by Turner of many thousands of New and Old World specimens, both ancient and modern, suggest that the majority of prehistoric Americans are linked to Northern Asian populations by crown and root traits such as incisor shoveling (a scooping out on one or both surfaces of the tooth), single-rooted upper first premolars6 and triple-rooted lower first molars.

ii Dental evidence

iii Greenberg`s analysis of the dental and linguistic evidence

section E 的解法也类似，paragraph E 中开头就是一个问句。在考试中遇到问句，考生需要把问句本身和回答问句的句子一并仔细阅读。 这两句话和vi选项分别有 further和 how far does other，genetic evidence 和 DNA 两对同义替换词。考生在这种情况下可以很肯定的选择Vi。 section F的题目设计较新也比较狡猾。大家通过阅读F段可以很快找到文章的前两句话中与III选项中分别有language和linguistics, teeth和dental evidence两对同义替换词，很多同学会很坚定的选择III。很可惜，本题的正确答案是II。前文中我们提过，II 和 III选项较为类似，不同的是III中包含了Greenberg 这个人名也多出了linguistic这个信息。 III选项错误的原因就是 Greenberg这个人物在文中只是个语言学家没有研究过牙科证据，而这一信息恰恰出现在文章中唯一不需要阅读的最后一段。所以，本题题目的设计是相当精妙的。考生不但要选择出能概括段落的选项，还不能忘记所选答案一定要是正确的。

所以，从以上的分析可以看出， List of Headings这类题型是对学生英语能力的考察。考生很难像部分细节题一样根据一个经验猜测答案。但是只要掌握了正确的做题原则还是可以事半功倍。