搜索结果 | GMAT考满分，百万出国党的口碑之选。

GMAT考满分·题库

收录题目9362道

搜索结果共9178条

来源

题目内容

In 1994, a team of scientists led by David McKay began studying the meteorite ALH84001, which had been discovered in Antarctica in 1984. Two years later, the McKay team announced that ALH84001, which scientists generally agree originated on Mars, contained compelling evidence that life once existed on Mars. This evidence includes the discovery of organic molecules in ALH84001, the first ever found in Martian rock. Organic molecules-complex, carbon-based compoundsform the basis for terrestrial life. The organic molecules found in ALH84001 are polycyclic . aromatic hydrocarbons, or PAHs. When microbes die, their organic material often decays into PAHs. Skepticism about the McKay team's claim remains, however. For example, ALH84001 has been on Earth for 13,000 years, suggesting to some scientists that its PAHs might have resulted from terrestrial contamination. However, McKay's team has demonstrated that the concentration of PAHs increases as one looks deeper into ALH84001 , contrary to what one would expect from terrestrial contamination. The skeptics' strongest argument, however, is that processes unrelated to organic life can easily produce all the evidence found by McKay's team, including PAHs. For example, star formation produces PAHs. Moreover, PAHs frequently appear in other meteorites, and no one attributes their presence to life processes. Yet McKay's team notes that the particular combination of PAHs in ALH84001 is more similar to the combinations produced by decaying organisms than to those originating from nonbiological processes.

In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers. Possibly as numerous as conventional galaxies, these galaxies have the same general shape and even the same approximate number of stars as a common type of conventional galaxy, the spiral, but tend to be much larger. Because these galaxies' mass is spread out over larger areas, they have far fewer stars per unit volume than do conventional galaxies. Apparently these low-surface-brightness galaxies, as they are called, take much longer than conventional galaxies to condense their primordial gas and convert it to stars——that is, they evolve much more slowly.These galaxies may constitute an answer to the long-standing puzzle of the missing baryonic mass in the universe. Baryons-subatomic particles that are generally protons or neutrons-are the source of stellar, and therefore galactic, luminosity, and so their numbers can be estimated based on how luminous galaxies are. However, the amount of helium in the universe, as measured by spectroscopy, suggests that there are far more baryons in the universe than estimates based on galactic luminosity indicate. Astronomers have long speculated that the missing baryonic mass might eventually be discovered in intergalactic space or as some large population of galaxies that are difficult to detect.

The dry mountain ranges of the Western United States contain rocks dating back 440 to 510 million years, Line to the Ordovician period, and teeming with evidence of tropical marine life.This rock record provides clues about one of the most significant radiations (periods when existing life-forms gave rise to variations that would eventually) evolve into entirely new species) in the history of marine invertebrates. During this radiation the number of marine biological families increased greatly, and these families included species that would dominate the marine ecosystems of the area for the next 215 million years. Although the radiation spanned tens of millions of years, major changes in many species occurred during a geologically short time span within the radiation and, furthermore, appear to have occurred worldwide, suggesting that external events were major factors in the radiation. And, in fact, there is evidence of major ecological and geological changes during this period: the sea level dropped drastically and mountain ranges were formed, in this instance, rather than leading to large-scale extinctions, these kinds of environmental changes may have resulted in an enriched pattern of habitats and nutrients, which in turn gave rise to the Ordovician radiation, However, the actual relationship between these environmental factors and the diversification of life forms is not yet fully understood

Ready4

Work Order Number	$W1$	$W2$	$W3$	$W4$	$W5$	$W6$
Fraction of Total Job	$\frac{1}{32}$	$\frac{1}{16}$	$\frac{1}{8}$	$\frac{3}{16}$	$\frac{9}{32}$	$\frac{5}{16}$

Lise receives batches of work orders from her supervisor. Her supervisor would like her to complete a total of 6 work orders on Thursday and Friday of this week. The table above shows the fraction each work order represents as a part of the total job. Assume Lise completes an entire work order in one sitting. Each work order is labeled either $W1$ , $W2$ , $W3$ , $W4$ , $W5$ , or $W6$ . If the work orders on Thursday made up more than $\frac{1}{2}$ of the total job, was $W3$ completed on Thursday?

(1) Lise completed $W5$ on Thursday.

(2) Lise completed exactly three work orders on Friday.

In American Genesis, which covers the century of technological innovation in the United States beginning in 1876,Thomas Hughes assigns special promi- nence to Thomas Edison as archetype of the independent nineteenth-century inventor. However, Hughes virtually ignores Edison's famous contemporary and notorious adversary in the field of electric light and power, George Westinghouse. This comparative neglect of Westinghouse is consistent with other recent historians' works, although it marks an intriguing departure from the prevailing view during the inventors' lifetimes (and for decades afterward) of Edison and Westinghouse as the two "pioneer innovators" of the electrical industry.My recent reevaluation of Westinghouse, facilitated by materials found in railroad archives, suggests that while Westinghouse and Edison shared important traits as inventors, they differed markedly in their approach to the business aspects of innovation. For Edison as an inventor, novelty was always paramount: the overriding goal of the business of innovation was simply to generate funding for new inventions. Edison therefore undertook just enough sales, product development, and manufacturing to accomplish this. Westinghouse, however, shared the attitudes of the railroads and other industries for whom he developed innovations: product development, standardization, system, and order were top priorities. Westinghouse thus better exemplifies the systematic approach to technological development that would become a hallmark of modern corporate research and development.

(The following is excerpted from material written in 1992.)Many researchers regard Thailand's recent economic growth, as reflected by its gross domestic product (GDP) growth rates,as an example of the success of a modern technological development strategy based on the market economics of industrialized countries. Yet by focusing solely on aggregate economic growth data as the measure of Thailand's development, these researchers have overlooked the economic impact of rural development projects that improve people's daily lives at the village level — such as the cooperative raising of water buffalo, improved sanitation, and the development of food crops both for consumption and for sale at local markets; such projects are not adequately reflected in the country's GDP. These researchers, influenced by Robert Heilbroner's now outdated develop- ment theory, tend to view nontechnological development as an obstacle to progress. Heilbroner's theory has become doctrine in some economics textbooks: for example, Monte Palmer disparages nontechnological rural development projects as inhibiting constructive change. Yet as Ann Kelleher's two recent case studies of the Thai villages Non Muang and Dong Keng illustrate, the nontechnological-versus-technological dichotomy can lead researchers not only to overlook real advances achieved by rural development projects but also mistakenly to conclude that because such advances are initiated by rural leaders and are based on traditional values and practices, they retard "[hl:2]real[/hl:2]" economic development.

In colonial Connecticut between 1670 and 1719, women participated in one of every six civil cases, the vast majority of which were debt-related. Women's participation dropped to one in ten cases after 1719, and to one in twenty by the 1770's. However, as Cornelia Hughes Dayton notes in Women Before the Bar: Gender, Law, and Society in Connecticut, 1639-1789, these statistics are somewhat deceptive: in fact, both the absolute numbers and the percentage of adult women participating in civil cases grew steadily throughout the eighteenth century, but the legal activity of men also increased dramatically, and at a much faster rate. Single, married, and widowed women continued to pursue their own and their husbands' debtors through legal action much as they had done in the previous century, but despite this continuity, their place in the legal system shifted dramatically. Men's commercial interests and credit networks became increasingly far-flung, owing in part to the ability of creditors to buy and sell promissory notes (legal promises to pay debts). At the same time, women's networks of credit and debt remained primarily local and personal. Dayton contends that, although still performing crucial economic services in their communities—services that contributed to the commercialization of the colonial economy—women remained for the most part outside the new economic and legal culture of the eighteenth century.

Ready4

Each of three plants, $P_{1}$ , $P_{2}$ , and $P_{3}$ , photosynthesizes glucose at a constant, characteristic rate measured in molecules per minute. If $p_{1}$ is the ratio of $P_{1}$ 's rate to $P_{2}$ 's rate and $p_{2}$ is the ratio of $P_{2}$ 's rate to $P_{3}$ 's rate, is $P_{3}$ 's rate the greatest of the three?

$p_{1} < p_{2}$
$p_{2} < 1$

The dry mountain ranges of the western United States contain rocks dating back 440 to 510 million years, to the Ordovician period, and teeming with evidence of tropical marine life. This rock record provides clues about one of the most significant radiations (periods when existing life-forms gave rise to variations that would eventually evolve into entirely new species) in the history of marine invertebrates. During this radiation the number of marine biological families increased greatly, and these families included species that would dominate the marine ecosystems of the area for the next 215 million years. Although the radiation spanned tens of millions of years, major changes in many species occurred during a geologically short time span within the radiation and, furthermore, appear to have occurred worldwide, suggesting that external events were major factors in the radiation. In fact, there is evidence of major ecological and geological changes during this period: the sea level dropped drastically and mountain ranges were formed. In this instance, rather than leading to large-scale extinctions, these kinds of environmental changes may have resulted in an enriched pattern of habitats and nutrients, which in turn gave rise to the Ordovician radiation. However, the actual relationship between these environmental factors and the diversification of life-forms is not yet fully understood.

In addition to conventional galaxies, the universe contains very dim galaxies that until recently went unnoticed by astronomers. Possibly as numerous as conventional galaxies, these galaxies have the same general shape and even the same approximate number of stars as a common type of conventional galaxy, the spiral, but tend to be much larger. Because these galaxies' mass is spread out over larger areas, they have far fewer stars per unit volume than do conventional galaxies. Apparently these low-surface-brightness galaxies, as they are called, take much longer than conventional galaxies to condense their primordial gas and convert it to stars-that is, they evolve much more slowly. These galaxies may constitute an answer to the long-standing puzzle of the missing baryonic mass in the universe. Baryons-subatomic particles that are generally protons or neutrons-are the source . of stellar, and therefore galactic, luminosity, and so their numbers can be estimated based on how luminous galaxies are. However, the amount of helium in the universe, as measured by spectroscopy, suggests that there are far more baryons in the universe than estimates based on galactic luminosity indicate. Astronomers have long speculated that the missing baryonic mass might eventually be discovered in intergalactic space or as some large population of galaxies that are difficult to detect.

According to a theory advanced by researcher Paul Martin, the wave of species extinctions that occurred in North America about 11,000 years ago, at the end of the Pleistocene era, can be directly attributed to the arrival of humans, i.e., the Paleoindians, who were ancestors of modern Native Americans. However, anthropologist Shepard Krech points out that large animal species vanished even in areas where there is no evidence to demonstrate that Paleoindians hunted them. [hl:5]Nor were extinctions confined to large animals: small animals, plants, and insects disappeared[/hl:5], presumably not all through human consumption. Krech also contradicts Martin's exclusion of climatic change as an explanation by asserting that widespread climatic change did indeed occur at the end of the Pleistocene. Still, Krech attributes secondary if not primary responsibility for the extinctions to the Paleoindians, arguing that humans have produced local extinctions elsewhere. But, according to historian Richard White, even the attribution of secondary responsibility may not be supported by the evidence. White observes that Martin's thesis depends on coinciding dates for the arrival of humans and the decline of large animal species, and Krech, though aware that the dates are controversial, does not challenge them; yet [hl:3]recent archaeological discoveries[/hl:3] are providing evidence that the date of human arrival was much earlier than 11,000 years ago.

Traditional social science models of class groups in the United States are based on economic status and assume that women's economic status derives from association with men, typically fathers or husbands, and that women therefore have more compelling common interest with men of their own economic class than with women outside it. Some feminist social scientists, by contrast, have argued that the basic division in American society is instead based on gender, and that the total female population, regardless of economic status, constitutes a distinct class. Social historian Mary Ryan, for example, has argued that in early nineteenth-century America the identical legal status of working-class and middle-class free women outweighed the differences between women of these two classes: married women, regardless of their family's wealth, did essentially the same unpaid domestic work, and none could own property or vote. Recently, though, other feminist analysts have questioned this model, examining ways in which the condition of working-class women differs from that of middle-class women as well as from that of working-class men. Ann Oakley notes, for example, that the gap between women of different economic classes widened in the late nineteenth century: most working-class women, who performed wage labor outside the home, were excluded from the emerging middle-class ideal of femininity centered around domesticity and volunteerism.

OG15 OG16 OG17

The following appeared as part of an article in a local newspaper:"Over the past three years the tartfish industry has changed markedly: fishing technology has improved significantly, and the demand for tartfish has grown in both domestic and foreign markets. As this trend continues, the tartfish industry on Shrimp Island can expect to experience the same overfishing problems that are already occurring with mainland fishing industries: without restrictions on fishing, fishers see no reason to limit their individual catches. As the catches get bigger, the tartfish population will be dangerously depleted while the surplus of tartfish will devalue the catch for fishers. Government regulation is the only answer: tartfish-fishing should be allowed only during the three-month summer season, when tartfish reproduce and thus are most numerous, rather than throughout the year."Discuss how well reasoned you find this argument. In your discussion be sure to analyze the line of reasoning and the use of evidence in the argument. For example, you may need to consider what questionable assumptions underlie the thinking and what alternative explanations or counterexamples might weaken the conclusion. You can also discuss what sort of evidence would strengthen or refute the argument, what changes in the argument would make it more logically sound, and what, if anything, would help you better evaluate its conclusion.

Ready4

What is the area of the circle above with center O?

The area of $Δ O A B$ is 50.
The length of arc ACB is $15 π$ .

For many years, historians thought that the development of capitalism had not faced serious challenges in the UnitedStates. Writing in the early twentieth century, [hl:2]Progressive historians[/hl:2] sympathized with the battles waged by farmers and small producers against large capitalists in the late nineteenth century, but they did not question the widespread acceptance of laissez-faire (unregulated) capitalism throughout American history. Similarly, Louis Hartz, who sometimes disagreed with the Progressives, argued that Americans accepted laissez-faire capitalism without challenge because they lacked a feudal, precapitalist past. Recently, however, some [hl:2][hl:3]scholars[/hl:3][/hl:2] have argued that even though laissez-faire became the prevailing ethos in nineteen-century America, it was not accepted without struggle. Laissez-faire capitalism, they suggest, clashed with existing religious and communitarian [hl:3]norms[/hl:3] that imposed moral constraints on acquisitiveness to protect the weak from the predatory, the strong from corruption, and the entire culture from materialist excess. Buttressed by mercantilist notions that government should be both regulator and promoter of economic activity, these norms persisted long after the American Revolution helped unleash the economic forces that produced capitalism. These scholars argue that even in the late nineteenth century, with the government's role in the economy considerably diminished, laissez-faire had not triumphed completely. Hard times continued to revive popular demands for regulating business and softening the harsh edges of laissez-faire capitalism.

The United States hospital industry is an unusual market in that nonprofit and for-profit producers exist simultaneously. Theoretical literature offers conflicting views on whether nonprofit hospitals are less financially efficient. Theory suggests that nonprofit hospitals are so much more interested in offering high-quality service than in making money that they frequently input more resources to provide the same output of service as for-profit hospitals. This priority might also often lead them to be less vigilant in streamlining their services--eliminating duplication between departments, for instance. Conversely, while profit motive is thought to encourage for-profit hospitals to attain efficient production, most theorists admit that obstacles to that efficiency remain. For-profit hospital [hl:3]managers[/hl:3], for example, generally work independently of hospital owners and thus may not always make maximum financial efficiency their highest priority. The literature also suggests that widespread adoption of third-party payment systems may eventually eliminate any such potential differences between the two kinds of hospitals.The same literature offers similarly conflicting views of the efficiency of nonprofit hospitals from a social welfare perspective. Newhouse (1970) contends that nonprofit hospital managers unnecessarily expand the quality and quantity of hospital care beyond the actual needs of the community, while Weisbrod (1975) argues that nonprofit firms--hospitals included--contribute efficiently to community welfare by providing public services that might be inadequately provided by government alone.

Ready4

The table above shows the results of a survey of 100 customers of a particular company, each of whom gave a "Positive," "Negative" or "Neutral" rating of the company's product and its customer service. What was the number of customers who rated both the company's product and its service negatively?

Forty customers did not give any "Negative" ratings at all, whether for product or service
Thirty customers rated both product and service "Positive"

The fields of antebellum (pre-Civil War) political history and women's history use separate sources and focuson separate issues. Political historians, examining sources such as voting records, newspapers, and politicians' writings, focus on the emergence in the 1840's of a new "American political nation," and since women were neither voters nor politicians, they receive little discussion. Women's historians, meanwhile, have shown little interest in the subject of party politics, instead drawing on personal papers, legal records such as wills, and records of female associations to illuminate women's domestic lives, their moral reform activities, and the emergence of the woman's rights movement.However, most historians have underestimated the extent and significance of women's political allegiance in the antebellum period. For example, in the presidential election campaigns of the 1840's, the Virginia Whig party strove to win the allegiance of Virginia's women by inviting them to rallies and speeches. According to Whig propaganda, women who turned out at the party's rallies gathered information that enabled them to mold party-loyal families, reminded men of moral values that transcended party loyalty, and conferred moral standing on the party. Virginia Democrats, in response, began to make similar appeals to women as well. By the mid-1850's the inclusion of women in the rituals of party politics had become common- place, and the ideology that justified such inclusion had been assimilated by the Democrats.

Acting on the recommendation of a British government committee investigating the high incidence in white lead factories of illness among employees, most of whom were women, the Home Secretary proposed in 1895 that Parliament enact legislation that would prohibit women from holding most jobs in white lead factories. Although the Women's Industrial Defence Committee (WIDC), formed in 1892 in response to earlier legislative attempts to restrict women's labor, did not discount the white lead trade's potential health dangers, it opposed the proposal, viewing it as yet another instance of limiting women's work opportunities. Also opposing the proposal was the Society for Promoting the Employment of Women (SPEW), which attempted to challenge it by investigating the causes of illness in white lead factories. [line:17][hl:2]SPEW contended, and WIDC concurred, that controllable conditions in such factories were responsible for the development of lead poisoning.[/line:17][/hl:2] SPEW provided convincing evidence that lead poisoning could be avoided if workers were careful and clean and if already extant workplace safety regulations were stringently enforced. However, the Women's Trade Union League (WTUL), which had ceased in the late 1880s to oppose restrictions on women's labor, supported the eventually enacted proposal, in part because safety regulations were generally not being enforced in white lead factories, where there were no unions (and little prospect of any) to pressure employers to comply with safety regulations.

Ready4

The works of two nineteenth century thinkers promote conflicting theories of the locus of responsibility for the course of historical events. Thomas Carlyle, in his 1841 treatise On Heroes, Hero-Worship, and the Heroic in History, places little emphasis on the events or conditions that produce major figures or the environments that allow them to rise to prominence. Instead, Carlyle posits that the extraordinary charisma, intelligence, wisdom, or political skill of individual “great” figures, invariably men, are the primary means by which social progress is effected. Herbert Spencer (1820–1903), though, writes not only that social environments are responsible for any great figures societies produce, but that Carlyle's approach is puerile and “unscientific” in the vein of many popular sociological works of the era. Although both thinkers promote a theory attempting to isolate the “mechanisms” of history vis-à-vis individual figures, only Spencer's has survived recent criticism largely intact. He emphasizes the lesser-understood contingencies of progress that comprise the immense majority of sociohistorical phenomena. He concludes that while major figures often take credit for the causal chain of significant events, the individuals themselves are less directly responsible for them than is commonly believed. This generality demonstrates how Spencer laid the foundation for twentieth-century historical scholarship, which holds to the belief that historical events, even those led by “heroes,” follow from multitudinous and sometimes untraceable social preconditions.