四六级

　　各位考生朋友们！2017年6月英语六级考试将在17日进行，2017年6月英语六级考试倒计时只有3天了，大家一定不要放松练习！想要拿到理想分数？那就调整好心态坚持复习吧！下面小编整理了英语六级阅读考前三天突破训练题，各位考生要加油哦！

　　In the atmosphere, carbon dioxide acts rather like a one-way mirror-the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents che heat from escaping.

　　According to a weather expert's prediction. the atmosphere will be 3C warmer m the year 2050 than it is today, if man continues to bum fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt. thus raising sea level several meters and severely flooding coastal cities. Also, the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly re9ulting in an alteration of the earth's chief food-growing zones.

　　In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming: in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels.

　　Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth.

　　However. most of the fuel is burnt in the northern Hemisphere, where temperatures seem to be falling. Scientists conclude. therefore. that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has most effect on the weather?

　　One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and "cold” spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days. it presents hotter or "colder" faces to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on che distribution of the earth's atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles. che latest trend being, downward.

　　Scientists are now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that che models are predicting that the world should be entering a new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia (惯性) of the earth's climate. If this is right. the warming effect of carbon dioxide might thus be serving as a useful counterbalance to the sun’s diminishing heat.

　　1. It can be concluded that a concentration of carbon dioxide in the atmosphere would______.

　　A) prevent the sun's rays from reaching the earth's surface

　　B) mean a warming up in the Arctic

　　C) cause great climate changes in the northern hemisphere

　　D) raise the temperature of the earth's surface

　　2.The article was written io explain____________.

　　A) the greenhouse effect.

　　B) che sola:r effects on the earth.

　　C) the models of solar-weather interactions.

　　D) the causes affecting weather.

　　3.Why is the fuel consumption greater in the northern hemisphere. but temperatures there seem to be falling?

　　A) Mainly because the levels of carbon dioxide are rising.

　　B) Possibly because the ice caps in the poles are melting.

　　C) Because the inertia of the earth's climate take effect.

　　D) Partly because the output of solar energy varies.

　　4.On the basis of their models. scientists are of the opinion that_______.

　　A) the climate of the world should be becoming cooler

　　B) it will take thousands of years for the inertia of the earth's climate to take effect

　　C) the man-made warming effect helps to increase the solar effects

　　D) the new Ice Age will be delayed by the greenhouse effect

　　5.If the assumption about the delayof a new Ice Age is correct,___________.

　　A) the best way to overcome the cooling effect would be to burn more fuels

　　B) ice would soon cover the northern hemisphere

　　C) the increased levels of carbon dioxide could warm up the earth quickly.

　　D) the greenhouse effect could work to the advantage of the earth.

　　答案：

　　1.可以推断出，大气中二氧化碳的集中将__________。

　　A)阻止太阳的光线到达地表

　　B)意味着北极的升温

　　C)导致北半球大的气候改变

　　D)导致地表温度升高

　　[D]从第1段对二氧化碳造成温室效应的原理描述，即可判断本题答案为D项。根据第4段第3句“这种情况符合二氧化碳使地球变暖的理论”也可判断D项符合题意。此外，本题也可以根据有关温室效应的常识求解。

　　2.作者撰写这篇文章，是为了解释____________。

　　A)温室效应

　　B)地球受到的太阳效应

　　C)太阳与气象相互作用的模型

　　D)影响天气的因素

　　[D]文章前半部分(前四段)讲燃烧产生二氧化碳使地球产生温室效应，后半部分(后三段)讲太阳对地球的影响使地球温度降低。尤其值得注意的是第5段提出的问题Which natural cause has most effect on the weather? 使我们推出本文旨在解释影响气候变化的原因。故D项为正确答案。

　　3.为什么北半球燃油消耗更大，但是它的温度看似却下降了?

　　A)主要是因为(大气中)二氧化碳含量上升了。

　　B)可能是因为极地的冰盖正在融化。

　　C)因为地球气候的惯性起作用了。

　　D)一定程度上是因为太阳能的输出变化了。

　　[D]从第5段最后一句给出的设问可知，第6段的首句是考点之所在，即：“一种可能性(自然因素)是变化无常的太阳活动”。由此可以判断，D项的内容符合题意。A项说的是人为的因素，即温室效应。事实上，A项和D项是作为两个影响气候的对立因素出现的，同时也是本文论及的两个分话题，由此也可以直接判断D项为正确答案。

　　4.根据他们的模型，科学家们持这一观点：

　　A)全球的气候应该变冷。

　　B)地球气候的惯性需要几千年才起作用。

　　C)人为的升温效应助推太阳效应。

　　D)新的冰河时代将因温室效应而被推后。

　　[A]最后一段的第2句提到“科学家们研究的结果应该是地球进入新的冰川时期，然而却没有出现这种情况”，这与A项的内容吻合。D项为本题的强干扰项，根据文章，该项的含义正确。但就本题而言，题干针对的是models(模型)，因而判断范隔只能针对solar-weather interactions.即太阳的作用。

　　5.如果关于新冰河时代延迟的设想是正确的，那么__________。

　　A)战胜变冷效应的最好办法是烧更多的燃料

　　B)北半球将很快被冰雪覆盖

　　C)(大气中)二氧化碳含量的增加会致使地球迅速升温

　　D)温室效应将良性地作用于地球

　　[D]文章最后一句中的a useful counter-balance是指有益的抵消作用，即二氧化碳产生的热效应可以抵消太阳热量减少使地球变冷的倾向，这对地球的热量平衡是有利的。这与D项的内容相吻合。

　　成功往往青睐于那些努力学习并坚持到最后的人！各位考生，加油！文都网校四六级频道预祝各位六级考试顺利！

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