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+第四五篇 Small But WiseOn December 14,NASA1 blasted a small but mighty telescope into space. The telescope iscalled WISE and is about as wide around as a trashcan. Dont let its small size fool you:WISE hasa powerful digital camera, and it will be taking pictures of some the wildest objects2 in the knownuniverse,including asteroids,faint stars,blazing galaxies3 and giant clouds of dust where planetsand stars are born.Im very excited because were going to be seeing parts of the universe that we havent seenbefore,said Ned Wright, a scientist who directs the WISE project.Since arriving in space,the WISE telescope has been circling the Earth,held by gravity in apolar orbit4(this means it crosses close to the north and south poles with each lap5).Its camera ispointed outward,away from the Earth,and WISE will snap a picture of a different part of the skyevery 11 minutes. After six months it will have taken pictures across the entire sky.The pictures taken by WISE wont be like everyday digital photographs,however. WISEstands forWide-field Infrared Survey Explorer.As its name suggests,the WISE camera takespictures of features that give off infrared radiation6.Radiation is energy that travels as a wave. Visible light, including the familiar spectrum oflight7 that becomes visible in a rainbow,is an example of radiation. When an ordinary digitalcamera takes a picture of a tree,for example,it receives the waves of visible light that are reflected off the tree. When these waves enter the camera through the lens,theyre processed by the camera,which then puts the image together.Waves of infrared radiation are longer than waves of visible light, so ordinary digital camerasdont see them,and neither do the eyes of human beings. Although invisible to the eye,longerinfrared radiation can be detected as warmth by the skin.Thats a key idea to why WISE will be able to see things other telescopes cant. Noteverything in the universe shows up in visible light. Asteroids,for example,are giant rocks thatfloat through space 一but they absorb most of the light that reaches them. They dont reflect light,so theyre difficult to see. But they do give off infrared radiation, so an infrared telescope like WISE will be able to produce images of them. During its mission WISE will take pictures ofhundreds of thousands of asteroids.Brown dwarfs8 are another kind of deep-space object that will show up in WISEs pictures.These objects arefailed stars 一which means they are not massive enough to jump start9 thesame kind of reactions that power stars such as the sun. Instead,brown dwarfs simply shrink andcool down. Theyre so dim that theyre almost impossible to see with visible light, but in theinfrared spectrum they glow.词汇：trashcan / tr,kn/n垃圾箱infrared/infrred/ adj红外线asteroid/strid/ n.小行星dwarf/dw:f/ n. 矮星注释：1.NASA （美国国家航空航天局）是缩写词，全称是National Aeronautics and SpaceAdministration2. the wildest objects ：任何你能想象得到的天体。wild 有“未被人驯养的”“荒唐的”“离奇的”意思。3. faint stars, blazing galaxies：指的是那些只能看到微弱的光和因燃烧而无法观察到的天体。4. polar orbit：极地轨道。指轨道平面与赤道面夹角为90。的人造地球卫星轨道。人造卫星运行时能到达南北极区上空，即卫星能飞经全球范围的上空。需要在全球范围内进行观测和应用的气象卫星、导航卫星、地球资源卫星等都采用这种轨道。5. lap：一圈。原指竞赛场的一圈或游泳池的一个来回，如： She overtook the other runners on the last lap. 她最后一圈超过了其他参赛者。6. infrared radiation：红外线辐射7. spectrum of light：光谱，即，光辐射的波长分布区域。8. Brown dwarfs：褐矮星。褐矮星非常暗淡，很难发现它们，要确定它们的大小就更加困难。9.jump start: 启动练习：1 .What is so special about WISE?A It is small in size but carries a large camera.B It is as small as a trashcan.C Its digital camera can help astronomers to see the unknown space.D Never before has a telescope carried a digital camera in space.2. Which is NOT the synonym for the word snap in the third paragraph?A make.B shoot.C takeD photograph.3. The camera on WISEA is no different from an ordinary camera.B does not see infrared radiation while the ordinary camera does.C catches the infrared radiation while the ordinary camera does not.D reflects light that human eyes can see.4. Which of the following is NOT correct aboutasteroids according to paragraph 7?A Asteroids float through space giving off visible light.B Asteroids do not reflect light that reaches them.C It is difficult to take asteroids pictures by ordinary cameras,D The WISE telescope can take pictures of asteroids5.What is implied in the last paragraph?A Brown dwarfs give off visible light.B Brown dwarfs give off infrared radiation.C Brown dwarfs are power stars like the sun.D Brown dwarfs are impossible to see with the WISE telescope.答案与题解：1. C 短文的第一和第二段提供了答案。WISE 的特殊之处就在于，虽然体积小，但它的数码相机能拍到任何天体，所以能够帮助天文学家观测到宇宙空间中（ in the known universe ）的未知天文现象。其他选项都不是短文表达的意思。2. A snap 是个多义词，可以解释为“拍照”，更为确切的意思是“拍快照”。这里shoot, take 和photograph 都是snap 的同义词。3. C 短文第六段和第四段提供了答案。人类的肉眼和普通相机看到的光是visible lights ，看不见红外线辐射（ infrared radiation) ，而WISE 的相机能够看到。4. A 短文第七段第二句说并非所有的宇宙中的物体都会发出可见光，比如asteroids ，所以A是正确选项。其他选项的内容都可以在该段中找到。5. B 最后一段的第一句说，褐矮星能出现在WISE 照片中，根据上文对WISE 望远镜的描述只有WISE 望远镜才能拍到红外线射线，所以B是正确选择。+第四十六篇Ants Have Big Impact on Environment as Ecosystem EngineersResearch by the University of Exeter1 has revealed that ants have a big impact on their local environment as a result of their activity as ecosystem engineers and predators. The study, published in the Journal of Animal Ecology, found that ants have two distinct effects on their local environment.Firstly, through moving of soil by nest building2 activity and by collecting food they affect the level of nutrients in the soil. This can indirectly impact the local populations of many animal groups, from decomposers to species much higher up the food chain.Secondly, they prey on a wide range of other animals, including larger prey which can be attacked by vast numbers of ant workers.Dirk Sanders, an author of the study from the universitys Centre for Ecology and Conservation, said:Ants are very effective predators which thrive in huge numbers. Theyre also very territorial3 and very aggressive, defending their resources and territory against other predators. All of this means they have a strong influence on their surrounding area.In this research, we studied for the first time how big this impact is and the subtleties of it. What we found is that despite being predators, their presence can also lead to an increase in density and diversity of other animal groups4. They genuinely play a key role in the local environment, having a big influence on the grassland food web, Sanders said.The study, carried out in Germany, studied the impact of the presence of different combinations and densities of black garden ants and common red ants, both species which can be found across Europe, including in the UK. It found that a low density of ants in an area increased the diversity and density of other animals in the local area, particularly the density of herbivores and decomposers. At higher densities ants had no or the opposite effect, showing that predation is counteracting the positive influence.Dr Frank van Veen, another author on the study, said:What we find is that the impact of ants on soil nutrient levels has a positive effect on animal groups at low levels, but as the number of ants increases, their predatory impacts have the bigger effect thereby counteracting the positive influence via ecosystem engineering.Ants are important components of ecosystems not only because they constitute a great part of the animal biomass5 but also because they act as ecosystem engineers. Ant biodiversity6 is incredibly high and these organisms are highly responsive to human impact, which obviously reduces its richness. However, it is not clear how such disturbance damages the maintenance of ant services to the ecosystem Ants are important in below ground processes8 through the alteration of the physical and chemical environment and through their effects on plants, microorganisms, and other soil organisms.词汇：predator / predt/ n食肉动物nutrient/ nju:trint/ n 营养物；adj营养的decomposer/,di:kmpuz/ n腐生物；分解体prey/prei/ v捕食；n被捕食的动物subtlety/ stlti/ n ，微妙，精妙herbivore/ h:biv: / n 食草动物注释：1.the University of Exeter ：埃克斯特大学。1851 年建校，位于英国西南部重要商业中心埃克斯特市，是英国著名的传统大学之一。2. nest building ：筑巢3. territorial ：领地的。在此用来形容蚂蚁的本性，即具有很强的领地意识，并且会竭尽全力保卫自己的领地。4. an increase in density and diversity of other animal groups ：其他动物群体在数量和品种上的增长。5. biomass ：物质名词，由bio和mass 两部分组成，意为“生物量”“生物质”。6. biodiversity ：物质名词，由bio和diversity 两部分组成，意为“生物多样性”。7.the maintenance of ant services to the ecosystem ：蚂蚁对生态系统的维护作用。8. below ground processes ：土壤下面的（工作）过程，即影响生态环境的过程。练习：1 .Why are ants compared to ecosystem engineers?A Because they build their own nests.B Because they collect food.C Because their activity affects the environment.D Because they are predators.2. As predators, antsA prey on small as well as large animals.B collect nutritious food from the soilC collect food as decomposers.D prey on species much higher up the food chain.3. Dir Sanders study centered on how antsA can manage to thrive in huge numbers.B defend their resources and territory against other predators.C attack those invading animals for survival.D produce such a big impact on the environment.4. What does paragraph 6 tell us?A Ants bring about a negative influence to an area when their population is small.B Ants bring about a positive influence to an area when their population is small.C Ants predation counteracts the positive influence they may have on an area.D At higher density, ants produce a positive influence on an area.5. What still remains unclear about ants, according to the last paragraph?A What roles do ants play in the ecosystem in which they live?B How do ants affect the animal diversity in a given ecosystem?C How do human activities affect ants influence on a given ecosystem?D How do ants alter the physical and chemical environment?答案与题解：1. C 短文的第一段提供了答案。A不是正确答案，因为并不是因为蚂蚁会筑巢才被誉为生态系统工程师，而是因为它们筑巢和获取食物的方式改变了土壤的营养水平，为整个食物链提供了很好的生态环境（见第二段）。2.A答案能够从短文的第三段直接找到。该段告诉我们，蚂蚁的掠食范围很广，甚至包括比它们体积更大的动物（ larger animals) 。 prey 在这里的意思是“捕猎，捕食”，作为动词，后面跟介词on或upon。3.D Dirk Sanders说：“In this research, we studied for the first time how big this impact is and the subtleties of it.”（第五段）所以，D是正确选择。句中the subtleties of it 的意思是：蚂蚁对环境影响的精妙之处。4.B 短文第六段第二句的大概意思是，蚂蚁数量小（a low density of ants）的话，能使其他动物的品种和数量增加（increased the diversity and density of other animals），从而给环境带来积极影响；第三句说，如果蚂蚁的数量大（At higher densities），就不可能产生同样的影响，或者是相反的影响，这表明，蚂蚁的掠食活动会抵销蚂蚁给环境带来的积极影响。第七段Dr Frank van Veen 表达了大体相同的内容。5.C 最后一段的第二和第三句提供了答案。第二句告诉我们，蚂蚁极易受人类的影响（these organisms are highly responsive to human impact），第三句告诉我们，科学家还不清楚人类对蚂蚁这种干扰如何破坏蚂蚁对生态系统的维护作用（”it is not clear how such disturbance damages the maintenance of ant services to the ecosystem.”）。
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