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托福阅读解析:甲烷和PETM(20161210托福)

2016-12-12 12:15:32来源:网络

  新东方在线托福网为大家带来托福阅读真题解析:甲烷和PETM(20161210托福)一文,希望对大家托福备考有所帮助。更多精彩尽请关注新东方在线托福网!阅读新题解析

  今天阅读3篇文章是The Age of Industrialism(工业化的时代),Effects of Predation on Species Distribution(捕猎对物种分布的影响),Methane and the PETM(甲烷和PETM),是一套新题。第1篇文章“工业化时代”,属于常考话题,但切入点很独特,讲述的却是工业化的缺点(pitfalls),全文长难句遍布,语言难度较大;第2、3篇重点考查理科事物发展的来龙去脉,前后连贯性非常强。尤其是第3篇,是阅读中第一次涉及的话题,让很多考生不适应,下面重点分析这一篇。

  首先看标题“Methane and the PETM”,很多考生便受到惊吓,这里有两个单词比较难,一个是methane(甲烷),必须认识,文章中没有提供任何解释的机会,是考生必须掌握的必会词;另一个是PETM,是专业术语,文章首段必然会做出解释,而且概念的解释经常是考点,注意精准理解。

  首段第1句:Near the end of the Paleocene, some 55 million years ago, global temperatures increased dramatically and suddenly during a relatively brief period known as the Paleocene-Eocene Thermal Maximum, or PETM. 下定义“sth. …known as…”解释什么是PETM,原来PETM是Paleocene末期的一个相对短暂时期,在这期间全球温度急剧地突然上升,被称为“Paleocene-Eocene Thermal Maximum”,简称PETM。第2句:The discovery that a large change occurred at this time in the ratio of carbon-13 and carbon-12 isotopes in sea sediments provided clues to its possible cause. 原因是考点,是什么原因导致此时全球温度突然急剧上升?同位素碳12/13的比例变化为为此提供线索。什么线索?继续推动思维下行。第3句:The abruptness of the isotope ratio shift indicates that a large amount of previously sequestered (burried) carbon was suddenly released into the ocean-atmosphere system. 线索表明先前埋于海底沉淀物的碳被释放到大气海洋系统,这跟全球变暖有什么关系?前后思维还未联结,继续追问,向下文推进。第4句:The size and direction of the shift suggest that the form of carbon being injected was methane, a carbon-based greenhouse gas.被释放的碳是以甲烷methane形式存在,甲烷是温室气体,一语打到要害,连接起了和全球变暖的因果关系。

  考题

  第30题According to paragraph 1, which of the following statements about the PETM is true?

  解析:考查概念和因果关系。

  全文主体段落讲述大量的碳是以什么样的方式(甲烷水合冰methane hydrate)如何被储存在海底沉淀物里(低温高压条件下),以及又以什么样的方式被分解释放出来,而且为什么会选择在Paleocene末期的一个相对短暂时期内大量释放,是什么原因促成的。行文里处处充满因果关系和多重因果关系的传递。如It is possible that a shift in ocean circulation—without an overall increase in seawater temperature—simply brought warmer water to some regions, triggering methane release, which in turn caused a general warming of the climate, which led to more methane release in a kind of snowball effect.

  其它考题

  第32题Paragraph 2 supports which of the following statements about why methane hydrate can exist in continental shelves? (因果是考点)

  第34题According to paragraph 3, methane hydrate deposits are found only in certain specific environments in part because methane hydrate (因果是考点)

  第39题According to paragraph 4, all of the following mechanisms could possibly have contributed to a huge methane release EXCEPT(因果是考点)

  第40题 According to paragraph 4, which of the following is true about the mechanisms that might have caused the extremely large release of methane? (因果是考点)

  以上就是新东方在线托福网为你带来的托福阅读真题解析(20161210托福),更多精彩敬请关注新东方在线托福网。


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