雅思阅读如何寻找信号词
雅思阅读考试考查的不仅是对文章的理解，还有很多文章语段中的细节，通过题干去锁定关键词信息对考生来说尤为重要，要善于寻找文章中的信号词。
雅思阅读 如何寻找信号词?
雅思阅读题会设置很多的同义词转换，寻找答案的难度就提高了一个level，怎么办，这时候文章中的信号词变成了救命稻草，一起来了解一下如何寻找雅思阅读中的信号词吧。
雅思阅读信号词之特殊信号词
特殊的信号词，一般都比较容易识别，如果遇到题目中涉及到，一般大写字母开头的人名，地名，专有名词，以及特殊印刷体和黑体，这些词在英语文章中显得尤为突出，往往也是题干中关键词的原词定位。
例 如 'the US Congress voted NASA $10 million per year for ten years to conduct a thorough search for the extra-terrestrial life' 这句话，出现了US Congress, NASA 专有名词信号词，极有可能成为定位的讯息。的确，判断题型中有一题‘the NASA project attracted criticism from some members of Congress.' 就是根据这两个信号词精确地回到原文定位。
雅思阅读信号词之普通信号词
雅思阅读作为一项专业的语言水平测试，当然不能只依靠容易识别的特殊信号词，文章中的普通信号词对于解题可谓是功不可没。
1)信号词之原因
例 如reason, cause, since, in that, as, because, thanks to, owing to, 解释说明某一事物或事件，往往会蕴含重要信息。如'since the lifetime of a planet like ours is several billion years, we can expect that…' 该句是之后简答题'what is the life expectancy of Earth' 的答案信息来源，如果考生只定位Earth, 那就很有可能失分，因为原句对Earth 做了同义替换的表述，而since这个信号词则提示了答案所在的地方。
2)信号词之结论
例 如 thus, therefore, so, hence, consequently, as a result, 这些词往往是对前面所论述的总结归纳，例如 'Tortoises therefore represent a remarkable double return’， 该句出现在整篇文章的末段首句，很明显是对前文的总结概括，高度浓缩了信息。最后的主旨选择题，就是对该句的改写：‘they have made the transition from sea to land more than once’。
3)信号词之转折
例 如however, but, by comparison, nonetheless, nevertheless，这些词往往表示文章观点或方向的重大转变，重点应该关注信号词后面的内容。如‘this definition implies that iconoclasts are different from other people, but more precisely, it is their brains that are different in three distinct ways’， 前半句指出iconoclasts异于常人，用but转折词，强调指出区别的关键地方。这也是选择题‘iconoclasts are distinctive because…' 的出题方向。
4)信号词之让步
例 如although, though, while, whereas, whilst等连接的句子，后半句才是引出的话题和强调内容。如'He accurately predicted that Venus would cross the face of the Sun in both 1761 and 1769--though he didn't survive to see either’， 前半句讲述他精确预测金星跨越太阳的两次时间，后半句用though引出让步内容，他没有看到任何一次。判断题中‘Halley observed one transit of the planet Venus’主要就是以原文定位句的后半句为判断依据。
5)信号词之举例
例 如for example, for instance, that is to say, such as, include, 后面引出具体事物的详细例子，同时原文中破折号和冒号也有异曲同工之妙，对前面的内容补充说明。如‘in other worlds, the life form we are looking for may well have two green heads and seven fingers, but it will nevertheless resemble us in that it should communicate with its fellows, be interested in the Universe, live on a planet orbiting a star like our Sun, and perhaps most restrictively, have a chemistry, like us, based on carbon and water.' 整句话都在解释说明该段的第二个假设'we are looking for a life form that is pretty well like us’，所举的例子也是判断题‘SETI scientists are trying to find a life form that resembles humans in many ways' 的判断依据。
6)信号词之顺序
例 如first, second, finally, eventually, later, then, next等，体现出文章内容的逻辑性与发展性。如'In discussing whether we are alone, most SETI scientists adopt two ground rules. First,…Second…’， 使用first 和second这两个序数词，清晰逻辑地讲述了两个重要的假设。这两个信号词，也是这篇文章heading题型段落大意的重点提示。
7)信号词之比较级
例 如more, most, -est, best, better,exclusively, extremely, superior, preferable，表示事物之间的比较，也是文章要强调的地方。如‘one part is a targeted search using the world's largest radio telescopes, the American-operated telescope’， 该句的the world's largest radio telescopes 对应了题目中the world's most powerful radio telescopes，答案信息就在这里。
雅思考试阅读模拟练习及答案
1 There’s a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star’s core.
2 Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun’s interior. According to the standard view, the temperature of the sun’s core is held constant by the opposing pressures of gravity and nuclear fusion. However, Ehrlich believed that slight variations should be possible.
3 He took as his starting point the work of Attila Grandpierre of the Konkoly Observatory of the Hungarian Academy of Sciences. In 2005, Grandpierre and a collaborator, Gábor Ágoston, calculated that magnetic fields in the sun’s core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.
4 Ehrlich’s model shows that whilst most of these oscillations cancel each other out, some reinforce one another and become long-lived temperature variations. The favoured frequencies allow the sun’s core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years. Ehrlich says that random interactions within the sun’s magnetic field could flip the fluctuations from one cycle length to the other.
5 These two timescales are instantly recognisable to anyone familiar with Earth’s ice ages: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
6 Most scientists believe that the ice ages are the result of subtle changes in Earth’s orbit, known as the Milankovitch cycles. One such cycle describes the way Earth’s orbit gradually changes shape from a circle to a slight ellipse and back again roughly every 100,000 years. The theory says this alters the amount of solar radiation that Earth receives, triggering the ice ages. However, a persistent problem with this theory has been its inability to explain why the ice ages changed frequency a million years ago.
7 "In Milankovitch, there is certainly no good idea why the frequency should change from one to another," says Neil Edwards, a climatologist at the Open University in Milton Keynes, UK. Nor is the transition problem the only one the Milankovitch theory faces. Ehrlich and other critics claim that the temperature variations caused by Milankovitch cycles are simply not big enough to drive ice ages.
8 However, Edwards believes the small changes in solar heating produced by Milankovitch cycles are then amplified by feedback mechanisms on Earth. For example, if sea ice begins to form because of a slight cooling, carbon dioxide that would otherwise have found its way into the atmosphere as part of the carbon cycle is locked into the ice. That weakens the greenhouse effect and Earth grows even colder.
9 According to Edwards, there is no lack of such mechanisms. "If you add their effects together, there is more than enough feedback to make Milankovitch work," he says. "The problem now is identifying which mechanisms are at work." This is why scientists like Edwards are not yet ready to give up on the current theory. "Milankovitch cycles give us ice ages roughly when we observe them to happen. We can calculate where we are in the cycle and compare it with observation," he says. "I can’t see any way of testing [Ehrlich’s] idea to see where we are in the temperature oscillation."
10 Ehrlich concedes this. "If there is a way to test this theory on the sun, I can’t think of one that is practical," he says. That’s because variation over 41,000 to 100,000 years is too gradual to be observed. However, there may be a way to test it in other stars: red dwarfs. Their cores are much smaller than that of the sun, and so Ehrlich believes that the oscillation periods could be short enough to be observed. He has yet to calculate the precise period or the extent of variation in brightness to be expected.
11 Nigel Weiss, a solar physicist at the University of Cambridge, is far from convinced. He describes Ehrlich’s claims as "utterly implausible". Ehrlich counters that Weiss’s opinion is based on the standard solar model, which fails to take into account the magnetic instabilities that cause the temperature fluctuations.
Questions 1-4
Complete each of the following statements with One or Two names of the scientists from the box below.
Write the appropriate letters A-E in boxes 1-4 on your answer sheet.
A. Attila Grandpierre
B. Gábor Ágoston
C. Neil Edwards
D. Nigel Weiss
E. Robert Ehrlich
1. ...claims there抯 a dimmer switch inside the sun that causes its brightness to rise and fall in periods as long as those between ice ages on Earth.
2. ...calculated that the internal solar magnetic fields could produce instabilities in the solar plasma.
3. ...holds that Milankovitch cycles can induce changes in solar heating on Earth and the changes are amplified on Earth.
4. ...doesn’t believe in Ehrlich’s viewpoints at all.
Questions 5-9
Do the following statements agree with the information given in the reading passage?
In boxes 5-9 on your answer sheet write
TRUE if the statement is true according to the passage
FALSE if the statement is false according to the passage
NOT GIVEN if the information is not given in the passage
5. The ice ages changed frequency from 100,000 to 41,000 years a million years ago.
6. The sole problem that the Milankovitch theory can not solve is to explain why the ice age frequency should shift from one to another.
7. Carbon dioxide can be locked artificially into sea ice to eliminate the greenhouse effect.
8. Some scientists are not ready to give up the Milankovitch theory though they haven’t figured out which mechanisms amplify the changes in solar heating.
9. Both Edwards and Ehrlich believe that there is no practical way to test when the solar temperature oscillation begins and when ends.
雅思考试阅读模拟练习及答案
Questions 10-14
Complete the notes below.
Choose one suitable word from the Reading Passage above for each answer.
Write your answers in boxes 10-14 on your answer sheet.
The standard view assumes that the opposing pressures of gravity and nuclear fusions hold the temperature ...10...in the sun’s interior, but the slight changes in the earth’s ...11... alter the temperature on the earth and cause ice ages every 100,000 years. A British scientist, however, challenges this view by claiming that the internal solar magnetic ...12... can induce the temperature oscillations in the sun’s interior. The sun’s core temperature oscillates around its average temperature in ...13... lasting either 100,000 or 41,000 years. And the ...14... interactions within the sun’s magnetic field could flip the fluctuations from one cycle length to the other, which explains why the ice ages changed frequency a million years ago.
Answer keys and explanations:
1. E
See the sentences in paragraph 1(There’s a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star’s core.) and para.2 (Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun’s interior.)
2. A B
See para.3: ?i style=’normal’>Grandpierre and a collaborator, Gábor Ágoston, calculated that magnetic fields in the sun’s core could produce small instabilities in the solar plasma.
3. C
See para.8: Edwards believes the small changes in solar heating produced by Milankovitch cycles are then amplified by feedback mechanisms on Earth.
4. D
See para.11: Nigel Weiss, a solar physicist at the University of Cambridge, is far from convinced. He describes Ehrlich’s claims as "utterly implausible".
5. False
See para.5: for the past million years, ice ages have occurred roughly every 100,000 years. Before that, they occurred roughly every 41,000 years.
6. False
See para.7: "In Milankovitch, there is certainly no good idea why the frequency should change from one to another," ... Nor is the transition problem the only one the Milankovitch theory faces.
7. Not Given
See para.8: if sea ice begins to form because of a slight cooling, carbon dioxide?is locked into the ice. That weakens the greenhouse effect. (The passage doesn抰 mention anything about locking Co2 into ice artificially.)
8. True
See para.9: there is no lack of such mechanisms. "If you add their effects together, there is more than enough feedback to make Milankovitch work,"?"The problem now is identifying which mechanisms are at work." This is why scientists like Edwards are not yet ready to give up on the current theory.
9. True
See the sentences in para.9 (According to Edwards, 卙e says. "I can’t see any way of testing [Ehrlich’s] idea to see where we are in the temperature oscillation.") and para.10 (Ehrlich concedes this. "If there is a way to test this theory on the sun, I can’t think of one that is practical).
10. constant
See para.2: According to the standard view, the temperature of the sun’s core is held constant by the opposing pressures of gravity and nuclear fusion.
11. orbit
See para.6: Most scientists believe that the ice ages are the result of subtle changes in Earth’s orbit, 匛arth’s orbit gradually changes shape from a circle to a slight ellipse and back again roughly every 100,000 years.
12. instabilities
See para.3: ?i style=’magnetic fields in the sun’s core could produce small instabilities in the solar plasma. These instabilities would induce localised oscillations in temperature.
13. cycles
See para.4: …allow the sun’s core temperature to oscillate around its average temperature of 13.6 million kelvin in cycles lasting either 100,000 or 41,000 years.
14. random
See para.4: Ehrlich says that random interactions within the sun’s magnetic field could flip the fluctuations from one cycle length to the other
