2012届高三英语二轮复习精品 课件（湖北专用）：第3模块 阅读理解 专题8 科普知识型阅 读理解专题八 科普知识型阅读理解 专题导读专题八 专题导读科普类文章主要包括自然科学类、前沿科技发明类和医 疗卫生类， 其取材密切联系当前经济和科技等方面的变化 ， 以介绍某一科学现象居多。科普类文章具有结构严谨， 逻辑性强等特点。其主要命题形式有事实细节题、词义猜测 题、推理判断题以及主旨概括题等， 其中推理判断题居多 。 从词汇角度来看，在科普类文章中， 词汇的意义比较专 一、稳定、简明、不带感情色彩， 具有单一性和准确性的 特点。从语法和句子结构方面看， 句子结构较复杂， 长难 句较多， 语法分析较困难。文章中常用被动语态、定语从 句等。专题八 专题导读科普文常用的修辞手段有： 1. 下定义：有时为了突出事物的主要内容或主要问题， 往往用简明扼要的语言给对象一个说法，使读者对被说明的 对象有明确的概念。2. 举事例：举出有代表性的恰当的例子，能够反映一般 的情况，真切地说明事物特征。3. 做比较：选择有外部或内部联系的事物进行比较，往 往能增强说明事物的效果。4. 打比方：适当运用比喻，能够增强说明的形象性和生 动性。专题八 专题导读科普说明文在结构上常采用的写作方法有：1. 总分式。在说明事物或事理时，段落(层次)之间有一 个总分关系，表现为由总到分、由分到总。2. 承接式。各层之间按照事物的发展过程，或者按时间 、因果、条件等关系安排，前后相互承接。3. 递进式。后边在前边的基础上进一步说明，各层之间 的关系是由浅入深。文章的命题除了遵循科普阅读的命题方 式外， 还经常考查文章的篇章结构和修辞手法。真题典例专题八 真题典例2011湖南卷 A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct(不同的)species. The discovery was made by researchers at York and Harvard Universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephantsthe Asian elephant，African forest elephant，and African savanna elephant.专题八 真题典例Once they obtained DNA sequences(序列) from two fossils(化石)，mammoths and mastodons，the team compared them with DNA from modern elephants.They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths. The scientists used detailed genetic analysis to prove that the African savanna elephant and the African forest elephant have been distinct species for several million years.The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths.This result amazed all the scientists.专题八 真题典例There has long been debate in the scientific community that the two might be separate species，but this is the most convincing scientific evidence so far that they are indeed different species. Previously，many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species，despite the elephants significant size differences.The savanna elephant has an average shoulder height of 3.5 metres while the forest elephant has an average shoulder height of 2.5 metres.The savanna elephant weighs between six and seven tons， roughly double the weight of the forest elephant.But the专题八 真题典例fact that they look so different does not necessarily mean they are different species.However the proof lay in the analysis of the DNA.Alfred Roca，assistant professor in the Department of Animal Sciences at the University of Illinois，said， “We now have to treat the forest and savanna elephants as two different units for conservation purposes.Since 1950，all African elephants have been conserved as one species.Now that we know the forest and savanna elephants are two very distinctive animals，the forest elephant should become a bigger priority(优先)for conservation purposes.”专题八 真题典例( )1.One of the fossils studied by the researchers is that of _. Athe Asian elephant Bthe forest elephant Cthe savanna elephant Dthe mastodon elephant ( )2.The underlined word “divergence” in paragraph 4 means “_.” Aevolution Bexhibition Cseparation Dexamination 专题八 真题典例( )3.The researchers conclusion was based on a study of the African elephants _. ADNA Bheight Cweight Dpopulation ( )4.What are Alfred Rocas words mainly about? AThe conservation of African elephants. BThe purpose of studying African elephants. CThe way to divide African elephants into two units. DThe reason for the distinction of African elephants. ( )5.Which of the following can be the best title for the passage? ANaturalists Beliefs about Elephants BAmazing Experiments about Elephants CAn Unexpected Finding about Elephants DA Long Scientific Debate about Elephants专题八 新题预测【要点综述】本文为科普说明文。主要介绍关于大象的最新 研究成果：非洲大象被分成两种完全不同的品种非洲草原大 象和非洲森林大象。1D 细节理解题。根据第三段 “Once they obtained DNA sequences(序列)from two fossils(化石)，mammoths and mastodons, the team compared them with DNA from modern elephants.”可判断选D。2C 词义猜测题。根据第四段“The scientists used detailed genetic analysis to prove that the African savanna elephant and the African forest elephant have been distinct species for several million years.”可知，科学家已证实，非洲 的草原大象与非洲的森林大象几百万年来都不属于同一品种，即 可推断下句为“两种大象的分离应发生在”。由此可推断划线 词应意为“分离”，故选C。专题八 新题预测3A 细节理解题。根据第三段“Once they obtained DNA sequences(序列)from two fossils(化石)，mammoths and mastodons, the team compared them with DNA from modern elephants. They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths”可判 断研究者的结论是建立在对非洲大象的DNA的研究结果的基 础上的，故选A。专题八 新题预测4A 逻辑推理题。根据最后一段中的“Now that we know the forest and savanna elephants are two very distinctive animals, the forest elephant should become a bigger priority (优先)for conservat