雅思閱讀練習(xí)輔導(dǎo)試題及答案解析

1、雅思閱讀練習(xí)輔導(dǎo)試題及答案解析只有知識——-才能構(gòu)成巨大的財(cái)富的源泉，？既使土地獲得豐收，又使文化繁榮昌盛。愚昧從來沒有給人們帶來幸福；幸福的根源在于知識；知識會使精神和物質(zhì)的曉薄的原野變成肥沃的 土地，每年它的產(chǎn)品將以十倍的增長率，給我們帶來財(cái)富。以下是小編為大家搜索整理的雅思閱讀練習(xí)輔導(dǎo)試題及答案解析，希望能給大家?guī)韼椭「嗑蕛?nèi)容請及時關(guān)注我們應(yīng)屆畢業(yè)生考試網(wǎng)！1 There’s a dimmer switch inside the sun that causes its brightness to rise and fal

2、l 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

3、 sun’s interior. According to the standard view , the temperature of thesun’s core is held constant by the opposing pressuresof gravity and nuclear fusion. However, Ehrlich believed that slight variations should be possible.3 He took as his starting point the work of Attila Grand

4、pierre 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 lo

5、calised 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 ave

6、rage 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 famil

7、iar 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 0rbit known as the Milankovit

8、ch 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 proble

9、m 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

10、 the transition problem the only one the Milankovitch theory faces. Ehrlich and other critics claim that the temperature variations caused byMilankovitch cycles are simply not big enough to drive ice ages.8 However, Edwards believes the small changes in solar heating produced by Milankovitch cycles

11、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 eve

12、n 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

13、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 oscill

14、ation.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 d

15、warfs. 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 o

16、f 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 1-4Co

17、mplete 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 GrandpierreB. Gábor ágostonC. Neil EdwardsD. Nigel WeissE. Robert Ehrlich1. .claims there a dimmer sw

18、itch inside the sun that causes itsbrightness to rise and fall in periods as long as those between ice ages onEarth.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 a

19、nd the changes are amplified on Earth.4. .doesn’t believe in Ehrlich’s viewpoints at all.Questions 5-9Do the following statements agree with the information given in the reading passage?In boxes 5-9 on your answer sheet writeTRUE if the statement is true according to the passageF

20、ALSE if the statement is false according to the passageNOT GIVEN if the information is not given in the passage5. The ice ages changed frequency from 100000 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 sho

21、uld 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 Edwar

22、ds and Ehrlich believe that there is no practical way to test when the solar temperature oscillation begins and when ends.Questions 10-14Complete 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 standar

23、d view assumesthat the opposing pressuresof gravity and nuclear fusions hold the temperature .10.in the sun’s interior, but the slight changes in the earth’s .11alter the temperature on the earth and cause ice ages every 100, 000 years. A British scientist, however, challenges th

24、is view by claiming that the internal solar magnetic .12can induce the temperature oscillations in the sun’s interior. The sun’s core temperature oscillates around its average temperature in .13. lasting either 10(000 or 41,000 years. And the .14. interactions within the sun&

25、rsquo;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 explanations1. ESee the sentencesin paragraph 1(There’s a dimmer switch inside the sun that causes its brightness to

26、rise and fall on timescales of around 100, 000 years - exactly the same period as between ice ages onEarth. 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 temperat

27、ure fluctuations in the sun’s interior.)2. A BSee 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. CSee para

28、.8: Edwards believes the small changesin solar heating produced by Milankovitch cycles are then amplified by feedback mechanisms on Earth.4. DSee para.11: Nigel Weiss, a solar physicist at the University of Cambridge, is far from convinced. He describes Ehrlich’s claims as utterly implausi

29、ble.5. FalseSee 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. FalseSee para.7 In Milankovitch , there is certainly no good idea why the frequency should change from one to another . Nor is the transit

30、ion problem the only one the Milankovitch theory faces.7. Not GivenSee 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 passagedoesn 挾 mention anything about locking Co2 into ice artificially.)8. TrueSee par

31、a.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. TrueSee the sentencesin para.9 (According to Edwards, 勘 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 theor