1、GMAT（ VERBAL）阅读练习试卷 11及答案与解析 1 Neotropical coastal mangrove forests are usually “zonal,” with certain mangrove species foundpredominantly in the seaward portion of the habitat and other mangrove species on the morelandward portions of the coast. The earliest research on mangrove forests produced des
2、criptions ofspecies distribution from shore to land, without exploring the causes of the distributions. The idea that zonation is caused by plant succession was first expressed by J. H. Davis in a studyof Florida mangrove forests. According to Davis scheme, the shoreline is being extended in aseawar
3、d direction because of the “land-building” role of mangroves, which, by trapping sedimentsover time, extend the shore. As a habitat gradually becomes more inland as the shore extends, the“land-building” species are replaced. This continuous process of accretion and succession wouldbe interrupted onl
4、y by hurricanes or storm flushings. Recently the universal application of Daviss succession paradigm has been challenged. It appearsthat in areas where weak currents and weak tidal energies allow the accumulation of sediments,mangroves will follow land formation and accelerate the rate of soil accre
5、tion; succession willproceed according to Daviss scheme. But on stable coastlines, the distribution of mangrovespecies results in other patterns of zonation; “land building” does not occur. To find a principle that explains the various distribution patterns, several researchers have lookedto salinit
6、y and its effects on mangrove. While mangroves can develop in fresh water, they can alsothrive in salinities as high as 2.5 times that of seawater. However, those mangrove species found infreshwater habitats do well only in the absence of competition, thus suggesting that salinitytolerance is a crit
7、ical factor in competitive success among mangrove species. Research suggeststhat mangroves will normally dominate highly saline regions, although not because they requiresalt. Rather, they are metabolically efficient (and hence grow well) in portions of an environmentwhose high salinity excludes pla
8、nts adapted to lower salinities. Tides create different degrees ofsalinity along a coastline. The characteristic mangrove species of each zone should exhibit ahigher metabolic efficiency at that salinity than will any potential invader, including other speciesof mangrove. 1 The primary of the purpos
9、e of the passage is to_ （ A） refute the idea that the zonation exhibited in mangrove forests is caused by adaption to salinity （ B） describe the pattern of zonation typically found in Florida mangrove forests （ C） argue that Davis succession paradigm cannot be successfully applied to Florida mangrov
10、e forests （ D） discuss hypotheses that attempt to explain the zonation of coastal mangrove forests （ E） establish that plants that do well in saline forest environments requre salt to achieve maximum metabolic efficiency 2 According to the passage, the earliest research on mangrove forest produced w
11、hich of the following? （ A） Data that implied random patterns of mangrove species distribution （ B） Descriptions of species distribtutions suggesting zonation （ C） Descriptions of the development of mangrove forests over time （ D） Reclassification of species formerly thought to be identical （ E） Dat
12、a that confirmed the “land-building” role of mangroves 3 It can be inferred from the passage that Davis paradigm does NOT apply to which of the following? （ A） The shoreline of Florida mangrove forests first studies by Davis （ B） A shoreline in an area with weak currents （ C） A shoreline in an area
13、with weak idal energy （ D） A shoreline extended by “land-building” species of mangrove （ E） A shoreline in which few sediments can accumulate 4 Information in the passage indicates that the author would most probably regard which of following statements as INCORRECT? （ A） Coastal mangrove forests ar
14、e usually zonal. （ B） Hurricanes interrupt the process of accretion and succession that extends existing shorelines. （ C） Species of plants that thrive in a saline habitat require salt to flourish. （ D） Plants with the highest metabolic efficiency in a given habitat tend to exclude other plants from
15、 that habitat. （ E） Shoreline in areas with weak currents and trides are more likely to be extended through the porocess of accumulation of sediment than are shorleines with strong currents and tides. 5 Modern manufacturers, who need reliable sources of materials and technologically advancedcomponen
16、ts to operate profitably, face an increasingly difficult choice between owning theproducers of these items (a practice known as backward integration) and buying from independentproducers. Manufacturers who integrate may reap short-term rewards, but they often restrict theirfuture capacity for innova
17、tive product development. Backward integration removes the need for some purchasing and marketing functions, centralizersoverhead, and permits manufacturers to eliminate duplicated efforts in research and development.Where components are commodities (ferrous metals or petroleum, for example), backwa
18、rdintegration almost certainly boosts profits. Nevertheless, because product innovation meansadopting the most technologically advanced and cost-effective ways of making components,backward integration may entail a serious risk for a technologically active company-for example,a producer of sophistic
19、ated consumer electronics. A company that decides to make rather than buy important parts can lock itself into an outdatedtechnology. Independent suppliers may be unwilling to share innovations with assemblers withwhom they are competing. Moreover, when an assembler sets out to master the technology
20、 ofproducing advanced components, the resulting demands on its resources may compromise itsability to assemble these components successfully into end products. Long-term contracts withsuppliers can achieve many of the same cost benefits as backward integration withoutcompromising a companys ability
21、to innovate. However, moving away from backward integration is not a complete solution either. Developinginnovative technologies requires independent suppliers of components to invest huge sums inresearch and development. The resulting low profit margins on the sale of components threaten thelong-te
22、rm financial stability of these firms. Because the ability of end-product assemblers torespond to market opportunities depends heavily on suppliers of components, assemblers are oftenforced to integrate by purchasing the suppliers of components just to keep their suppliers inbusiness. 5 According to
23、 the passage, all of the following are benefits associated with backward integration EXCEPT_ （ A） improvement in the management of overhead expenses （ B） enhancement of profit margins on sales of components （ C） simplification of purchasing and marketing operations （ D） reliability of a source of ne
24、cessary components （ E） elimination of unnecessary research efforts 6 According to passage, when an assembler buys a firm that makes some important component of the end product that the assembler produces, independent suppliers of the same component may_ （ A） withhold technological innovations from
25、the assembler （ B） experience improved profit margins of on sales of their products （ C） lower their prices to protect themselves from competition （ D） suffer finanical difficluties and go out of business （ E） stop developing new versions of the component 7 Which of the following best describes the
26、way the last paragraph functions in the context of the passage? （ A） The last in a series of arguments supporting the central argument of the passage is presented. （ B） A viewpoint is presented which qualifies one presented earlier in the passage. （ C） Evidence is presented in support of the argumen
27、t developed in the preceding paragrap. （ D） Questions arising from the earlier discussion are identified as points of departure for further study of the topic. （ E） A specific example is presented to illustrate the main elements of argument presented in the earlier paragraphs. 8 According to the pas
28、sage, which of the following relationships between profits and investments in research and development holds true for producers of technologically advanced components? （ A） Modest investments are required and the profit margins on component sales are lowl. （ B） Modest investments are required but th
29、e profit margins on component sales are quite high. （ C） Despite the huge investments that are required, the profit margins on components sales are high. （ D） Because huge investments are required, the profit margins on component sales are low. （ E） Long-term contractual relationships with purchaser
30、s of components ensure a high ratio of profits to investment costs. 9 Homeostasis, an animals maintenance of certain internal variables within an acceptable range,particularly in extreme physical environments, has long interested biologists. The desert rat andthe camel in the most water-deprived env
31、ironments, and marine vertebrates in an all-waterenvironment, encounter the same regulatory problem: maintaining adequate internal fluid balance. For desert rats and camels, the problem is conservation of water in an environment where standingwater is nonexistent, temperature is high, and humidity i
32、s low. Despite these handicaps, desert ratsare able to maintain the osmotic pressure of their blood, as well as their total boy-water content, atapproximately the same levels as other rats. One countermeasure is behavioral: these rats stay inburrows during the hot part of the day, thus avoiding loss
33、 of fluid through panting or sweating,which are regulatory mechanisms for maintaining internal body temperature by evaporativecooling. Also, desert rats kidneys can excrete a urine having twice as high a salt content as seawater. Marine vertebrates experience difficulty with their water balance beca
34、use though there is noshortage of seawater to drink, they must drink a lot of it to maintain their internal fluid balance.But the excess salts from the seawater must be discharged somehow, and the kidneys of mostmarine vertebrates are unable to excrete a urine in which the salts are more concentrate
35、d than inseawater. Most of these animals have special salt-secreting organs outside the kidney that enablethem to eliminate excess salt. 9 Which of the following most accurately states the purpose of the passage? （ A） To compare two different approaches to the study of homeostasis （ B） To summarize
36、the findings of several studies regarding organisms maintenance of internal variables in extreme environments （ C） To argue for a particular hypothesis regarding various organisms conservation of water in desert environments （ D） To cite examples of how homeostasis is achieved by various organisms （
37、 E） To defend a new theory regarding the maintenance of adeuate fluid balance 10 According to the passage, the camel maintains internal fluid balance in which of the following ways? I. By behavioral avoidance of exposure to conditions that lead to fluid loss II. By an ability to tolearte high body t
38、emperatures III. By reliance on stored internal fluid supplies （ A） I only （ B） II only （ C） I and II only （ D） II and III only （ E） I, II, and III 11 It can be inferred from the passage that some mechanisms that regulate internal body temperature, like sweating and panting, can lead to which of the
39、 following? （ A） A rise in the external body temperature （ B） A drop in the bodys internal fluid level （ C） A decrease in the osmotic pressure of the blood （ D） A decrease in the amount of renal water loss （ E） A decrease in the urines salt content 12 It can be inferred from the passage that the aut
40、hor characterizes the camels kidney as “entirely unexceptional” (line 24) primarily to emphasize that it_ （ A） functions much as the kidney of a rat functions （ B） does not aid the camel in coping with the exceptional water loss resulting from the extreme conditions of its environment （ C） does not
41、enbale the camel to excrete as much salt as do the kidneys of marine vertebrates （ D） is similar in structure to the kidneys of most mammals living in water-deprived environments （ E） requires the help of other organs in eliminating excess salt 13 In the seventeenth-century Florentine textile indust
42、ry, women were employed primarily inlow-paying, low-skill jobs. To explain this segregation of labor by gender, economists have reliedon the useful theory of human capital. According to this theory, investment in human capital-theacquisition of difficult job-related skills-generally benefits individ
43、uals by making them eligible toengage in well-paid occupations. Womens role as child bearers, however, results in interruptionsin their participation in the job market (as compared with mens) and thus reduces theiropportunities to acquire training for highly skilled work. In addition, the human capi
44、tal theoryexplains why there was a high concentration of women workers in certain low-skill jobs, such asweaving, but not in others, such as combing or carding, by positing that because of their primaryresponsibility in child rearing women took occupations that could be carried out in the home. Ther
45、e were, however, differences in pay scales that cannot be explained by the human capitaltheory. For example, male construction workers were paid significantly higher wage than femaletaffeta weavers. The wage difference between these two low-skill occupations stems from thesegregation of labor by gen
46、der: because a limited number of occupations were open to women,there was a large supply of workers in their fields, and this “overcrowding” resulted in womenreceiving lower wages and men receiving higher wages. 13 The passage suggests that combing and carding differ from weaving in that combing and
47、 carding are_ （ A） low-skill jobs performed by primarily by women employees （ B） low-skill jobs that were not perfomed in the home （ C） low-skill jobs performed by both male and female employees （ D） high-skill jobs performed outside the home （ E） high-skill jobs performed by both male and female em
48、ployees 14 Which of the following, if true, would most weaken the explanation provided by the human capital theory for womens concentration in certain occupations in seventeenth-century Florence? （ A） Women were unlikely to work outside the home even in occupations whose hourse were flexible enough
49、to allow women to accommodate domestic tasks as well as paid labor. （ B） Parents were less likely to teach occupational skills to their daughters than they were to their sons. （ C） Womens participation in the Florentine paid labor force grew steadily throughout the xisteenth and seventeenth centuries. （ D） The vast amjority of female weavers in the Florenine wool industry had children. （ E） Few women worked as weavers in the Florentine silk industry, which was devoted to making cloths that requried a high degree of skill to produce. 15 The auth
