【正文】 However, when we are stressed for a long period, these stress hormones are everpresent in our bodies. And that, medical researchers warn, may lead to health problems.When you feel stressed or under pressure, your body releases many natural hormones (荷爾蒙) including adrenaline and cortisol. Adrenaline increases your heart rate and blood pressure. Cortisol is the body39。 Experts note that an unhealthy lifestyle can put you at great risk of heart disease and stroke. So doctors urge us to eat healthy foods, get exercise, stop smoking and limit our alcohol intake. But there is something else you can do. And it is free and easy. Smile! 【點評】本題考點涉及細節(jié)理解，詞義猜測和主旨大意三個題型的考查，是一篇科研類閱讀，要求考生在捕捉細節(jié)信息的基礎上，進一步根據(jù)上下文的邏輯關系，進行分析，推理，概括和歸納，從而選出正確答案。本文主要講述了人類以及其他動物對狼的恐懼對維持健康、平衡的生態(tài)系統(tǒng)是有益的，因為食草動物不會過度繁殖，從而保護了植物的生長。故選B。根據(jù)最后一段中的“The research is one more piece of evidence for why protecting these top predators is important not just for wolves as a species, but for hundreds of species at every level of an ecosystem.”可知，這項研究再次證明了為什么保護這些食肉動物不僅對狼這個物種很重要，而且對生態(tài)系統(tǒng)的各個層面的物種都很重要。故選D。 （2）考查細節(jié)理解。根據(jù)第三段中的We were really surprised at that可知，黃石公園在意想不到的方面從重新引入狼中獲益。The introduction of wolves in Yellowstone National Park is a success.【答案】 （1）A（2）D（3）B（4）A 【解析】【分析】本文是一篇說明文，研究表明人類以及其他動物對狼的恐懼對維持健康、平衡的生態(tài)系統(tǒng)是有益的，其中黃石公園灰狼的引進就是一個典型的例子。The fear of wolves put them in danger of disappearing.C.It provides evidence that wolves are endangered animals.（4）What is the main idea of the passage? A.It helps prove the importance of protecting wolves.C.To study what good wolves can do to ecosystems.（3）What is the significance of the research? A.To show how wolves benefit from ecosystems.C.Accept.（2）For what purpose was a documentary made? A.Notice.Understand.Expect. To learn more about just how wolves are beneficial, a short documentary from Quest explains how the presence of wolves influences the behavior of deer, which eventually makes entire ecosystems more biologically diverse and healthy. In this documentary, biologist Aaron Wirsing explored why wolves and other top predators （捕食者）were needed for diverse ecosystems to develop. Using a simple video camera, Wirsing is gaining a unique view point on predatorprey relationships and changing the way we think about wolves.t adopted ecologicalprocess management—allowing natural ecological processes to take place with least human intervention. Yellowstone has benefited from the reintroduction of wolves in ways that we did not anticipate, especially the plexity of biological interactions（互動） in the park, explained Mark Boyce, a professor in the Department of Biological Sciences. We were really surprised at that and we39。 Wolves strike fear into the hearts of many species, humans included. Our fear of them has brought them to the edge of dying out, as we have cruelly killed them as petitors and troublemakers. But researchers are discovering that the very fear they put into prey（被捕食者）species is exactly what helps make ecosystems（生態(tài)）healthy. 【點評】本題考點涉及推理判斷，代詞指代和主旨大意三個題型的考查，是一篇科研類閱讀，要求考生根據(jù)上下文的邏輯關系，進行分析，推理，概括和歸納，從而選出正確答案。因此蝙蝠與鳥不同，蝙蝠可以倒掛著。根據(jù)第三段中的Another interesting characteristic of bat flight is the way in which bats landupside down! Unlike birds which touch down on the ground or on tree branches, bats can be observed flying around and then suddenly hanging upside down from an object overhead. One downside to this landing routine is that the bats often land with some force, which probably causes pain.可知，蝙蝠飛行的另一個有趣特征是蝙蝠倒立著降落的方式！不同于那些降落在地上或樹枝上的鳥，觀察到蝙蝠可以四處飛行，然后突然倒掛在頭頂?shù)奈矬w上。故選C。劃線部分的上下文說蝙蝠在自我調節(jié)的能力上要好得多：蝙蝠可以迅速改變飛行方向，或者完全與它（正飛行方向）相反的方向飛行，這是鳥不容易做到的。根據(jù)第二段中的 In the past it was believed that, in terms of flying mechanics, there was little difference between bats and birds. This belief was based only on assumption, however, because for years nobody had actually studied in detail how bats move their wings…This makes coordinating (協(xié)調) their limbs more difficult for bats and, as a result, they are not very good at flying over longer distances.可推斷出，過去人們認為蝙蝠與鳥在飛行運動方式與鳥沒有區(qū)別，最近的研究發(fā)現(xiàn)，這是不正確的，故也是要糾正的，故選C。故選D。尤其是they are much better at the ability to adjust themselves: a bat can quickly change its direction of flight or pletely reverse it, something a bird cannot easily do可知蝙蝠與鳥的運動不同；第三段中的Another interesting characteristic of bat flight is the way in which bats landupside down! Unlike birds which touch down on the ground or on tree branches,…再一次說明了蝙蝠與鳥運動方式的不同。根據(jù)第一段中的Both bats and birds have mastered the skill of landing, but these two types of flyers go about it quite differently.提出了蝙蝠與鳥的降落方式及飛行的不同。以前人們認為蝙蝠和鳥類在運動方面沒有什么區(qū)別，但現(xiàn)在的研究證明蝙蝠的構造不同于鳥類，它們的翅膀由前肢和后肢組成，它們自我調節(jié)能力好，可迅速改變飛行方向，或完全逆行，這是鳥類不容易做到的，而且蝙蝠飛行的另一個有趣特征是蝙蝠倒立著降落的！這不同于那些降落在地上或樹枝上的鳥。D.Bats can hang upside down like birds.C.the ability to change the speed（4）According to the passage, which of the following is NOT true? A.the sense of flying heightC.the distance to the netsD.They fly similarly to birds.B.They cannot hear any sound.Differences in the eating habits of bats and birds.D.Places where flying animals choose to land.B. Another interesting characteristic of bat flight is the way in which bats landupside down! Unlike birds which touch down on the ground or on tree branches, bats can be observed flying around and then suddenly hanging upside down from an object overhead. One downside to this landing routine is that the bats often land with some force, which probably causes pain. However, not all bats hit their landing spots with the same speed and force。 Being able to land safely is a critically important skill for all flying animals. Comparatively speaking, ground living animals face no particular challenge when they need to stop running or crawling, while flying animals move at much higher speed, and they must be careful about how they land. Hitting the ground