如果懼怕前面跌宕的山岩，生命就永遠只能是死水一潭。以下是小編為大家搜尋整理的2017年GMAT考試閱讀理解，希望能給大家帶來幫助，更多精彩內容請及時關注我們應屆畢業生考試網!
In terrestrial environments, gravity places special demands on the cardiovascular systems of animals. Gravitational pressure can cause blood to pool in the lower regions of the body, making it difficult to circulate blood to critical organs such as the brain. Terrestrial snakes, in particular, exhibit adaptations that aid in circulating blood against the force of gravity.
The problem confronting terrestrial snakes is best illustrated by what happens to sea snakes when removed from their supportive medium. Because the vertical pressure gradients within the blood vessels are counteracted by similar pressure gradients in the surrounding water, the distribution of blood throughout the body of sea snakes remains about the same regardless of their orientation in space, provided they remain in the ocean. When removed from the water and tilted at various angles with the head up, however, blood pressure at their midpoint drops significantly, and at brain level falls to zero. That many terrestrial snakes in similar spatial orientations do not experience this kind of circulatory failure suggests that certain adaptations enable them to regulate blood pressure more effectively in those orientations.
One such adaptation is the closer proximity of the terrestrial snake's heart to its head, which helps to ensure circulation to the brain, regardless of the snake's orientation in space. The heart of sea snakes can be located near the middle of the body, a position that minimizes the work entailed in circulating blood to both extremities. In arboreal snakes, however, which dwell in trees and often assume a vertical posture, the average distance from the heart to the head can be as little as 15 percent of overall body length. Such a location requires that blood circulated to the tail of the snake travel a greater distance back to the heart, a problem solved by another adaptation. When climbing, arboreal snakes often pause momentarily to wiggle their bodies, causing waves of mmuscle contraction that advance from the lower torso to head. By compressing the veins and forcing blood forward, these contractions apparently improve the flow of venous blood returning to the heart.
文章概況:文章第一段開頭說地球的重力對血液迴圈造成一定的影響,而結尾舉了一個蛇的例子,說這種蛇有一種能力使得血液迴圈不受重力影響!
文章第二段拿sea snakes和第一段的 Terrestrial snakes進行類比,來說明 Terrestrial snakes確實有能力使血液迴圈不受重力影響!
文章第三段解釋了一下 Terrestrial snakes這種蛇具有這種特殊能力的原因,這個原因和這種動物心臟的位置有關係.後面舉了一些例子,涉及到了sea snake和arboreal snakes.
Question #25. 147-01 (22404-!-item-!-188;#058&000147-01)
The passage provides information in support of which of the following assertions?
(A) The disadvantages of an adaptation to a particular feature of an environment often outweigh the advantages of such an adaptation.
(B) An organism's reaction to being placed in an environment to which it is not well adapted can sometimes illustrate the problems that have been solved by the adaptations of organisms indigenous to that environment.
(C) The effectiveness of an organism's adaptation to a particular feature of its environment can only be evaluated by examining the effectiveness with which organisms of other species have adapted to a similar feature of a different environment.
(D) Organisms of the same species that inhabit strikingly different environments will often adapt in remarkably similar ways to the few features of those environments that are common.
(E) Different species of organisms living in the same environment will seldom adapt to features of that environment in the same way.
問主旨,我們直接來看選項
A 說這種adaptation的缺點比優點還要多,沒說,殺
B 說怎麼適應環境,和文章有點聯絡,留著
C only出現,過於極端,主旨題目的正確答案如果出現極端化詞彙就證明原文的作者是個瘋子了
D 說一種動物適應環境的方式和適應其他環境的方式是類似的,文章沒有這種比較,殺
E 住在相同環境的不同物種適應環境的方式是不同的.,文章也沒有出現過這種比較,殺
Question #26. 147-02 (22450-!-item-!-188;#058&000147-02)
According to the passage, one reason that the distribution of blood in the sea snake changes little while the creature remains in the ocean is that
(A)the heart of the sea snake tends to be located near the center of its body
(B) pressure gradients in the water surrounding the sea snake counter the effects of vertical pressure gradients within its blood vessels
(C) the sea snake assumes a vertical posture less frequently than do the terrestrial and the arboreal snake
(D) the sea snake often relies on waves of muscle contractions to help move blood from the torso to the head
the force of pressure gradients in the water surrounding the sea snake exceeds that of vertical pressure gradients within its circulatory system
這個問題提示作用實在是太強了,問為什麼sea snake放進水裡 distribution of blood沒變化的原因,答案要想正確至少得圍繞什麼談過?必須跟水有點關係啊!我們來看選項
A 和水沒關係,殺
B 和水有關係,留
C 和水沒關係,殺
D 和水沒關係,殺
E 和水有關係,留
B說的是壓力對血管的影響,E說兩種不同的壓力哪個大,你問的是壓力對distribution of blood的影響,選哪個?顯然是B.這就是問題的作用,對問題理解的比較精確,對原文的依賴就少.
Question #27. 147-07 (22496-!-item-!-188;#058&000147-07)
The author suggests that which of the following is a disadvantage that results from the location of a snake's heart in close proximity to its head?
(A) A decrease in the efficiency with which the snake regulates the flow of blood to the brain
(B) A decrease in the number of orientations in space that a snake can assume without loss of blood flow to the brain
(C) A decrease in blood pressure at the snake's midpoint when it is tilted at various angles with its head up
(D) An increase in the tendency of blood to pool at the snake's head when the snake is tilted at various angles with its head down
An increase in the amount of effort required to distribute blood to and from the snake's tail
問的是個細節題,蛇的心臟接近腦袋有什麼缺點,考的肯定是文章最後一段的內容,但這段開頭講的是心臟接近腦袋有什麼好處,你問的是缺點,在這段however這句方向開始發生變化,我們來讀一下這句.說有一種 arboreal snakes心臟離腦袋近,但是這個特點使得血液從尾巴流到腦子走的距離更長,我們來看選項
A 蛇控制血液流到腦子的效率下降,沒提,殺
B 數量少了,更沒提,殺
C 血壓下降,沒提,殺
D 沒提,殺
E 把血液送到尾巴並且從尾巴再送出更費勁了,有點,留著
Question #28. 147-09 (22542-!-item-!-188;#058&000147-09)
In the passage, the author is primarily concerned with doing which of the following?
(A) Explaining adaptations that enable the terrestrial snake to cope with the effects of gravitational pressure on its circulatory system
(B) Comparing the circulatory system of the sea snake with that of the terrestrial snake
(C) Explaining why the circulatory system of the terrestrial snake is different from that of the sea snake
(D) Pointing out features of the terrestrial snake's cardiovascular system that make it superior to that of the sea snake
(E) Explaining how the sea snake is able to neutralize the effects of gravitational pressure on its circulatory system
又問主旨,我們直接看選項了
A 說 terrestrial snake是如何適應重力的,有點關係,先留著
B 那兩種蛇進行對比,文章確實拿這兩種蛇進行了對比,但是這只是個細節,不是main idea,在GMAT大多數閱讀的錯誤答案都是原文提過但是不能回答問題導致的
C 解釋了為什麼兩種蛇系統不一樣的原因,沒說過,殺
D 指出為什麼一種蛇的系統比另外一種要好,文章只是一個客觀現象描述,這個選項用自己的標準來評價原文資訊的好壞,主觀答案,殺
E 解釋 sea snake如果能中和重力的影響,主體錯了,文章講的是 terrestrial snake如何解決重力影響的,sea snake只是中間的一個類比的例子,殺!
