真题实战
2015年真题
First Image-recognition Software
（1）Dartmouth researchers and their colleagues have created an artificial intelligence software that uses photos to locate documents on the Internet with far greater accuracy than ever before.
（2）The new system， which was tested on photos and is now being applied to videos， shows for the first time that a machine learning algorithm（运算法则）for image recognition and retrieval is accurate and efficient enough to improve large-scale document searches online.The system uses pixel（像素）data in images and potentially video — rather than just text — to locate documents.It learns to recognize the pixels associated with a search phrase by studying the results from text-based image search engines.The knowledge gleaned（收集）from those results can then be applied to other photos without tags or captions（图片说明）， making for more accurate document search results.
（3）“Over the last 30 years，” says Associate Professor Lorenzo Torresani， a co-author of the study， “the Web has evolved from a small collection of mostly text documents to a modern， massive， fast-growing multimedia data set， where nearly every page includes multiple pictures or videos.When a person looks at a Web page， he immediately gets the gist（主旨）of it by looking at the pictures in it.Yet， surprisingly， all existing popular search engines， such as Google or Bing， strip away the information contained in the photos and use exclusively the text of Web pages to perform the document retrieval.Our study is the first to show that modern machine vision systems are accurate and efficient enough to make effective use of the information contained in image pixels to improve document search.”
（4）He researchers designed and tested a machine vision system — a type of artificial intelligence that allows computers to learn without being explicitly programmed — that extracts semantic（语义的）information from the pixels of photos in Web pages.This information is used to enrich the description of the HTML page used by search engines for document retrieval.The researchers tested their approach using more than 600 search queries（查询）on a database of 50 million Web pages.They selected the text-retrieval search engine with the best performance and modified it to make use of the additional semantic information extracted by their method from the pictures of the Web pages.They found that this produced a 30 percent improvement in precision over the original search engine purely based on text.
23～26概括大意
23.Paragraph 1____
24.Paragraph 2____
25.Paragraph 3____
26.Paragraph 4____
A.Function of the new system
B.Improvement in document retrieval
C.Publication of the new discovery
D.Problems of the existing search engines
E.Popularity of the new system
F.Artificial intelligence software created
27～30完成句子
27.The new system does document retrieval by____.
28.The new system is expected to improve precision in____.
29.When performing document retrieval the existing search engines ignore____.
30.The new system was found more effective in document search than the____.
A.using photos
B.description of the HTML page
C.current popular search engines
D.document search
E.information in images
F.machine vision systems
2014年真题
Climate Change： The Long Reach
（1）Earth is warming.Sea levels are rising.There’s more carbon in the air， and Arctic ice is melting faster than at any time in recorded history.Scientists who study the environment to better gauge（评估）Earth’s future climate now argue that these changes may not reverse for a very long time.
（2）People burn fossil fuels like coal and oil for energy.That burning releases carbon dioxide，a colorless gas.In the air， this gas traps heat at Earth’s surface.And the more carbon dioxide released， the more the planet warms.If current consumption of fossil fuels doesn’t slow， the long-term climate impacts could last thousands of years—and be more severe than scientists had been expecting.Climatologist Richard Zeebe of the University of Hawaii at Manoa offers this conclusion in a new paper.
（3）Most climate-change studies look at what’s going to happen in the next century or so.During that time， changes in the planet’s environment could nudge（推动）global warming even higher.For example： Snow and ice reflect sunlight back into space.But as these melt，sunlight can now reach — and warm — the exposed ground.This extra heat raises the air temperature even more， causing even more snow to melt.This type of rapid exaggeration of impacts is called a “fast feedback”.
（4）Zeebe says it’s important to look at fast feedbacks.However， he adds， they’re limited.From a climate change perspective.“This century is the most important time for the next few generations，” he told Science News.“But the world is not ending in 2100.” For his new study， Zeebe now focuses on “slow feedbacks”.While fast feedback events unfold over decades or centuries， slow feedbacks can take thousands of years.Melting of continental ice sheets and the migration of plant life — as they relocate to more comfortable areas — are two examples of slow feedbacks.
（5）Zeebe gathered information from previously published studies investigating how such processes played out over thousands of years during past dramatic changes in climate.Then he came up with a forecast for the future that accounts for both slow and fast feedback processes.Climate forecasts that use only fast feedbacks predict a 4.5 degree Celsius（8.1 degree Fahrenheit）change by the year 3000.But slow feedbacks added another 1.5 °C—for a 6 total increase， Zeebe reports.He also found that stow feedback events will cause global warming to persist for thousands of years after people run out of fossil fuels to burn.
23～26 概括大意
23.Paragraph 2____
24.Paragraph 3____
25.Paragraph 4____
26.Paragraph 5____
A.Rising of sea levels
B.Impact of burning fossil fuels
C.Fast feedbacks
D.Slow feedbacks
E.Unpredictability of feedback processes
F.A prediction of future climate change
27～30完成句子
27.Arctic ice has never been melting so fast in____.
28.Melting of snow and ice enables sunlight to reach____.
29.Zeebe came up with his future climate prediction by analyzing____.
30.After fossil fuels are used up， global warming will continue for____.
A.the exposed ground
B.a very long time
C.the extra heat
D.recorded history
E.previously published studies
F.rapid exaggeration of impacts
2013年真题
Black Holes
（1）Black holes can be best described as a sort of vacuum， sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel， and because its temperature can no longer control the gravitational（重力的）force， hydrogen ends up putting pressure onto the star’s surface until it suddenly explodes then collapses.
（2）Black holes come from stars that are made of hydrogen， other gases and a few metals.When these explode it can turn into a stellar-mass（恒星质量）black hole， which can only occur if the star is large enough（should be bigger than the sun）for the explosion to break it into pieces， and the gravity starts to compact every piece into the tiniest particle.Try to see and compare：if a star that’s ten times the size of the sun end up being a black hole that’s no longer than 70 kilometers， then the Earth would become black hole that’s only a fraction of an inch！
（3）Objects that get sucked in a black hole will always remain there， never to break free.But remember that black holes can only gobble up（吞噬）objects within a specific distance to it.It’s possible for a large star near the sun to become a black hole， but the sun will continue to stay in place.Orbits（轨道）do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star， only this its mass is totally contracted that it can end up as no bigger than a state.
（4）So far， astronomers have figured out that black holes exist because of Albert Einstein’s theory of relativity.In the end， through numerous studies， they have discovered that black holes truly exist.Since black holes trap light and do not give off light， it is not possible to detect black holes via a telescope.But astronomers continue to explore galaxies（银河系）， space and the solar system to understand how black holes.It is possible that black holes can exist for millions of years， and later contribute further process in galaxies， which can eventually lead to creation of new entities.Scientists also credit black holes as helpful in learning how galaxies began to form.
23～26概括大意
23.Paragraph 1____
24.Paragraph 2____
25.Paragraph 3____
26.Paragraph 4____
A.Is there proof that black holes really exist？
B.What are different types of black holes？
C.How are black holes formed？
D.How were black holes named
E.What happens to the objects around a black hole？
F.What are black holes made of？
27～30 完成句子
27.Black holes are formed after____.
28.When a large star explodes， the gravity compacts ever piece into____.
29.A newly formed black hole and the star it comes from are of____.
30.Albert Einstein’s theory of relativity helps to prove____.
A.the creation of new entities
B.an explosion of huge stars
C.the tiniest particle
D.the same amount of mass
E.the existence of black holes
F.a fraction of an inch
答案与解析
2015年真题
23.F。题干：第一段的主要内容是____。第一段就一句话，大意是说Dartmouth的研究者及其同事发明了一种人工智能软件，该软件使用图片来定位网络文件，准确性较以前更高，故F（已经发明的人工智能软件）是正确答案。
24.A。题干：第二段的主要内容是____。第二段首句是主题句，新系统已在图片上进行过检测，现在正应用于视频，第一次表明一种学习图像辨识和检索运算法则的机器能精确和有效地改进大规模的网络文件搜索。该句讨论的是新系统的功用，故A（新系统的功能）是正确答案。
25.D。题干：第三段的主要内容是____。第三段的主题句为中间的句子，“yet”之前讨论的是网页的发展，“yet”之后讨论的则是现存的搜索引擎，诸如谷歌和必应等，无法使用图像中的信息而只能用文字进行文件的检索。因而，D（现存搜索引擎的问题）是正确答案。
26.B。题干：第四段的主要内容是____。第四段没有主题句，第一句讲新系统的机制，第二句讲新系统在文件检索中的功能，第三句讲研究者对新系统的检测以及检测效果，检测发现准确性提升了30%。故B（文件检索的改进）是正确答案。
27.A。题干：新系统通过____进行文件检索。利用出题顺序与段落顺序一致的原则，根据第一段可知，Dartmouth的研究者及其同事发明了一种人工智能软件，该软件使用图片（use photo）来定位网络文件，所以答案为A（使用图片）。
28.D。题干：新系统有望在____方面提升精确性。利用题干关键词new system和improve precision可以定位到第二段第一句，可知新系统已在图片上进行过检测，现在正应用于视频，第一次表明一种学习图像辨识和检索运算法则的机器能精确和有效地改进大规模的网络文件搜索（document searches），故选D（文件搜索）。
29.E。题干：在进行文件检索时，现存的搜索引擎忽视了____。利用题干关键词the existing search engines可以定位到第三段的第三句，也就是yet引导的句子，可知现在流行的搜索引擎都跳过了包含在图片中的信息而只能用网页的文字进行文件检索，由此可知这些搜索引擎忽视了利用图片信息进行文件检索，所答案为E（图片中的信息）。
30.C。题干：新系统比____在文件检索方面更有效。利用题干关键词new system和moreeffective可以定位到第三段的最后一句，可知与那些目前流行的搜索引擎如谷歌和必应相比，新系统有效使用包含在图像像素中的信息来检索文件，更加准确和有效。因此，该题答案选C（当前流行的搜索引擎）。
2014年真题
23.A。题干：第二段的主要内容是____。本段属于递进结构。首句讲到“人们经常燃烧化石燃料来获取热量和能量”，从第二句开始阐述燃烧化石燃料会释放二氧化碳，从而对气候产生影响。因此本段的主题是B（燃烧化石燃料的影响）。
24.C。题干：第三段的主要内容是____。该段的主题句为最后一句：这个过程叫作fast feedback。
25.D。题干：第四段的主要内容是____。该段为转折结构。第一句为引子“看快速反馈是十分重要的”，第二句前的however使得话锋一转，认为快速反应是有局限的，从而可推理得知该段的主题为slow feedback，这与该段中间的总结是一致的。故本题选D。
26.F。题干：第五段的主要内容是____。该段主题句为第二句：（在基于以前收集的信息基础上）他得出了解释未来快速反应与慢速反应进程的结论以及由此结论得到气候上升度数不同的结论。因此本题选F最合适。
27.D。题干：北极的冰在____从未融化得如此之快。根据Arctic ice回到原文定位到第一段第二句“Arctic ice is melting faster than at any time in recorded history.”可知，该空应该填入D。
28.A。题干：冰雪的融化使得阳光能达到____。根据melting snow and ice回到原文定位到第三段，由“But as these melt，sunlight can now reach — and warm — the exposed ground”可知该空应该填入the exposed ground。这里的these指代的就是melting snow and ice。
29.E。题干：Zeebe通过分析____预测了未来气候变化。通过Zeebe came up with his future climate prediction回到原文定位到最后一段，首句中有答案：收集以前的研究数据。
30.B。题干：化石燃烧尽了之后，全球变暖还会____。用 After fossil fuels are used up定位到末段的最后一句“cause global warming to persist for thousands of years after people run out of fossil fuels to burn”，可知该空答案为B。其中use up与run out对应，thousands of years对应选项中的a very long time。
2013年真题
23.C。第一段没有主题句，通过第二句可知黑洞形成是由于巨大的星体爆炸，第三句说明了巨大的星体是如何爆炸的，所以第一段讲的就是黑洞的形成过程，因此答案为C（黑洞是如何形成的）。
24.F。第二段首句是主题句，即“黑洞来自于那些由氢、其他气体以及一些金属组成的星体”，因而F选项（黑洞是由什么构成的）为正确答案。
25.E。第三段的主题句为首句，即“被黑洞吞噬的物体永远存在，永远不会逃逸出来”。但第二个句子是将but放在句首，所以重点就转向第二个句子，即“但是要记住黑洞只能吞噬与其保持特定距离的物体”，所以E（黑洞周围的物体会怎么样）为正确答案。
26.A。第四段的主题句是首句，即“到目前为止，天文学家根据爱因斯坦的相对论已经推断出黑洞的存在”，后面的句子都是有关天文学家对黑洞的研究，并且证明黑洞是真实存在的，所以A选项（有证据证明黑洞真实存在吗）为正确答案。
27.B。题干：黑洞是在____之后形成的。利用题干的关键词black holes和form可以定位到第一段第二句，可知科学家发现黑洞源于巨大的星体爆炸，所以正确答案为B（巨大星体的爆炸）。
28.C。题干：当巨大的星体爆炸时，重力将爆炸物压缩成____。利用题干的关键词 explode，compact，gravity可以定位到第二段：“…， and the gravity starts to compact every piece into the tiniest particle.”可知重力把爆炸产生的物体压缩成颗粒。因此此处填“最微小的粒子”，所以正确答案为C（最微小的颗粒）。
29.D。题干：新形成的黑洞和产生黑洞的那个星体____。利用题干关键词the newly formed black hole 可以定位到文章第三段“the newly formed black hole contains exactly the same amount of mass as when it was a star”，可知黑洞和形成黑洞的那个星体的质量相同，所以正确答案为D。
30.E。题干：爱因斯坦的相对论有助于证明____。利用题干关键词Albert Einstein’s theory定位到文章第四段第一句，可知天文学家断定黑洞的存在是因为爱因斯坦的相对论，所以正确答案为E。