- UID
- 1162059
- 在线时间
- 小时
- 注册时间
- 2015-10-8
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
17号美东战G~~攒人品咯~~期望能杀G成功~~
附件是po主根据本月悦读君整理的jj整理的精简版。。。感谢悦读君~！！！
希望整理版对大家有帮助吧~~~~现整理到#18 会陆续更新
------------------------------------------------以下是求鉴定的分割线------------------------------------------------
两篇悦读疑似原文，考过的大神们鉴定一下吧~~~
第一篇蛇类心脏供血的~~有构筑说是OG原文~~不知道OG中的题目有没有考到的呢？
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 muscle contraction that advance from the lower torso to the head. By compressing the veins and forcing blood forward, these contractions apparently improve the flow of venous blood returning to the heart.
文章第一段讲的陆生蛇的心脏很难将血液泵到大脑之中，因此陆生蛇进化出了一些功能，使得血液能够被泵到大脑之中。
（主旨题正确选项是文章解释陆生蛇的演化，这种演化使它能适应重力的影响；混淆选项是对比陆蛇和海蛇的血液循环系统）
第二段讲用海蛇并没有进化出这种功能，水的浮力刚好抵消了大脑受到的重力（此处有题，水的浮力和大脑重力谁大，文中给出counteract，选项应为same as），不需要再进化去克服在陆地上会受到的重力。当海蛇离开水面，水给的浮力一消失，蛇的大脑顿时会供血不足。因此得出结论，陆地上的蛇不在水中也活的好好的，一定是进化克服了供血问题。
第三段讲陆生蛇的两种不同进化，一种是使心脏离大脑更近。（此处有题，文中拿海蛇与陆蛇心脏位置做对比，海蛇不需要改变自己的心脏位置，心脏在中间）第二种进化是当蛇向上爬行时，大脑不得不高于心脏使得血液难以泵上去时，蛇会让自己肌肉收缩，使血液向上涌。
1. 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
B: pressure gradients in the water surrounding the sea snake counter the effects of vertical pressure gradients within its blood vessels
2. The passage provides information in support of which of the following assertions?
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.
3. It can be inferred from the passage that which of the following is true of species of terrestrial snakes that often need to assume a vertical posture?
Their hearts are less likely to be located at the midpoint of their bodies than is the case with sea snakes.
4. The author describes the behavior of the circulatory system of sea snakes when they are removed from 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.) primarily in order to
A. illustrate what would occur in the circulatory system of terrestrial snakes without adaptations that enable them to regulate their blood pressure in vertical orientations
5. It can be inferred from the passage that which of the following is a true statement about sea snakes?
They become acutely vulnerable to the effects of gravitational pressure on their circulatory system when they are placed in a terrestrial environment.
6. The author suggests that which of the following is a disadvantage that results from the location of snake’s heart in close proximity to its head?
E An increase in the amount of effort required to distribute blood to and from the snake’s tail
7. The primary purpose of the third paragraph is to
discuss two specific examples of phenomena mentioned at the end of the previous paragraph
8. In the passage, the author is primarily concerned with doing which of the following?
Explaining adaptations that enable the terrestrial snake to cope with the effects of gravitational pressure on its circulatory system
另外一篇是反垄断与并购的~~~顺着一位构筑给的线索找到一篇PDF
大概长这样。。 提到的表格数据什么的请无视。。。。
One prominent explanation for the decline in diversification centers on changes in antitrust enforcement (Posner, 1974; Shleifer and Vishny, 1991; Matsusaka, 1996). Tough enforcement in the 1960s and 1970s allegedly forced would-be acquirers to buy firms in unrelated industries. With laxer enforcement in the 1980s, firms were free to merge horizontally and diversification became less desirable. Our analysis of the role of antitrust is based on the observation that large firms are more likely to be constrained by antitrust than small firms. Antitrust enforcement has traditionally focused on market concentration and how a merger would affect the concentration (see, for example, Brown 16 Shoe Co. v. United States (1962) and United States v. Von’s Grocery Co. (1966).) The Department of Justice’s Merger Guidelines lay down conditions under which a merger will be scrutinized that depend on existing concentration of the market (as measured by Hirfindahl-Hirschman Index since 1982) and how much the merger will increase concentration. All else equal, a merger involving a large firm will increase concentration more than a merger involving a small firm.5 If antitrust was an important factor behind the decline of diversification, we should observe the greatest changes after 1981 among the largest firms because these were the firms most subject to antitrust scrutiny. To see if this is true, regressions (3) and (4) estimate how the return from diversifying changed over time separately for large and small firms. “Large” acquirers are defined to be firms whose market value three days before the announcement was in the top 10 percent of all publicly traded firms. About half of the sample fits into this group. The remaining firms are classified as “small” acquirers. In contrast to what the antitrust hypothesis predicts, the combined return from diversifying actually fell less for mergers involving large bidders than mergers involving small bidders. For large bidders, the return fell by 0.81 percent. For small bidders, the return fell by 1.36 percent. We estimated but do not report similar regressions that classified firms according to their size relative to firms in the sample (instead of all traded firms) with similar results. 5 For example, if A is the market share of the acquirer and T is the market share of the target, then the Hirfindahl-Hirschman Index increases by 2AT if they merge. 17 Columns (7) and (8) present similar regressions to explain the decline in the relative return from diversification. Regression (7) shows that for the largest acquirers, the relative return increased by an economically trivial 0.06 percent after 1980, while for smaller acquirers it fell by a statistically significant 1.58 percent. Whether measured in absolute or relative terms, the return from diversification appears to have fallen more for small firms than large firms, contrary to the antitrust hypothesis. The evidence in Table 2 points in the same direction as evidence in Matsusaka (1996) that also seems inconsistent with the antitrust hypothesis. Matsusaka finds that small firms were more likely to diversify than large firms in the late 1960s and early 1970s, even though antitrust would be expected to have induced the largest firms to diversify. For our sample, we find (but do not report) that large firms were 6 percent more likely to diversify before 1981, and 3 percent more likely to diversify afterwards, which supports the antitrust hypothesis, but the differences are modest and vanish when the five control variables are considered. Matsusaka also documents conglomerate merger waves in Britain, Canada, France, and Germany in the late 1960s even though those countries had no significant restrictions on horizontal mergers at the time.
|
本帖子中包含更多资源
您需要 登录 才可以下载或查看，没有帐号？立即注册
x
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2015-11-15 07:11:31
收藏
收藏
楼主