Reading Comprehension Test 73

[passage-header]Read the passage given below and answer the question that follows:[/passage-header]Early in the careers of most novelists, the critics nag and carp; later, the cold eye of reassessment is cast over their life work at the peak of a writing career, which is where Doris Lessing now stands, the years of solid achievement command maximum respect.

A survey of critical responses to Lessing's books might reveal curious strata of social history. It is hard to remember now that she was once considered very daring and very militant (she insisted that relations between the sexes were difficult and unequal). She has been accused of being a feminist and then accused by feminists of not being a feminist enough. She has been a communist but then moved on from a belief in simplistic political solutions to interest in deeper psychological change, touching on themes of madness and of mystical and extrasensory states of consciousness.

Lessing has written clearly into all her work the conviction that we are moving blindly and inevitably toward global catastrophe. Her message seems to be of complete moral and social bankruptcy, particularly in the relations between men and women. Hers is not an angry feminism, though her men are rather poor creatures compared to her bruised but gritty women. Anger may imply a hope that things could be better if only some sense could be knocked into somebody's head, a hope for a time 'after the revolution.' One does not feel that Lessing sees any hope, only perpetual deadlock.

Certainly, Lessing has earned the respect accorded to a writer 'of her stature and productivity'. Doggedly, she has been writing into her fiction signposts and warnings that we need desperately to be reminded of and writing in a way that has been more persuasive and imaginative than if she had been a pure polemicist. But the critic has the problem of distinguishing between what an author says and the way she says it. The moralist in Lessing, struggling with the very skilled writer, at times, has made her writing prolix, clogged, slow - though in her latest novels she has successfully introduced a leavening of fantasy. The fact is that there are writers who in an economical page or two can make us feel our dilemmas more piercingly than she does in a leisurely fictional experience. Missing from her work is that sense of time and space gathered up for a moment between the hands, that sudden shift from understanding to seeing directly, that we expect at rare moments from our storytellers.

[passage-header]Read the passage given below and answer the question that follows:[/passage-header]Scientists have developed a hydrogen-making catalyst that uses cheaper materials and yields much fewer contaminants than do the current processes while extracting the element from common renewable plant sources. Further, the new catalyst lies at the heart of a chemical process the authors say is a significant advance in producing alternate fuels from domestic sources.

In the journal of science, James Dumesic, John Shabaker, and George Huber of the University of Wisconsin at Madison report developing the catalyst from nickel, tin, and aluminum and using it in a process called aqueous-phase reforming (APR), which converts plant by-products into hydrogen. The process performs as well as current methods that use precious metals such as platinum, yet runs at lower temperatures and is much cleaner.

'The APR process can be used on the small scale to produce fuel for portable devices, such as cars, batteries, and military equipment,' said Dumesic. 'But it could also be scaled up as a hydrogen source for industrial applications, such as the production of fertilizers or the removal of sulfur from petroleum products.'

Hydrogen is a 'clean' fuel because when it burns, it combines with oxygen to form water; no toxic by-products or greenhouse gasses are produced in the process. The APR process extracts hydrogen from a variety of biological sources, especially simple carbohydrates, and sugars generated by common plants.

Platinum is known to be an excellent catalyst in a number of chemical reactions. It is one component in a car's catalytic converter, for example, that helps remove toxins from automobile exhaust. Catalytic platinum (Pt) and nickel (Ni) are preferred over other metals because they process reaction molecules much faster. But pure nickel, unlike platinum, recombines the hydrogen product with carbon atoms to make methane, a common greenhouse gas.

Using a specially designed reactor, the team found a match in a modified version of what researchers call a Raney-nickel catalyst. Raney-nickel is a highly porous catalyst made of about 90 percent nickel (Ni) and 10 percent Aluminium (AI).

While Raney-nickel proved somewhat effective at separating hydrogen from biomass-derived molecules, the researchers improved the material's effectiveness by adding more tin (Sn), which stops the production of methane and instead generates more hydrogen. Relative to the other catalysts, the new Raney-NiSn can perform for very long time periods (at least for about 48 hours) and at much lower temperatures (roughly 225 degrees Celsius).

[passage-header]Read the passage given below and answer the question that follows:[/passage-header]AGNI: In February 1994, the Agni was successfully test fired from the interim test range at Chandipur-on-sea near Balasore, Orissa. Agni is a surface-to-surface intermediate range ballistic missile, consisting of a solid propellant first stage and a liquid propellant second stage joined together by district trusses. While the missile is hurled into space by a solid fuel booster, the liquid-fueled second stage leads the missile warhead to its pre-designated target. It has a range of 1000 to 2500 km, a take-off weight of 19 tons and a payload capacity of 1 ton. The length of the missile at the third test was 21 meters, 2 meters more than it was on the maiden test flight in 1989. Agni is capable of carrying a multipurpose payload, indigenously built; one of its unique features is the heat shield of the re-entry vehicle. Made of a carbon-carbon composite, the heat shield is able to withstand temperatures of 5000 degrees Celsius. The heat shield being ablative, it melts and its outer layers peel off, taking away the heating layer by layer.

AKASH: Also launched in February 1994, it is a multi-target surface-to-air missile. Akash was successfully test fired at Chandipur-on-Sea. Its range is 25 km and it can target four to five enemy aircrafts and missiles at a time. Integrated with the indigenously produced Rajendra radar, it is capable of tracking many targets simultaneously. Such integrated rocket technology is better than conventional missile systems. The technology is said to be close to the system of the American Patriot missiles.

[passage-header]Read the passage and answer the question that follows:[/passage-header]In Winters v. United States (1908), the Supreme Court held that the right to use waters flowing through or adjacent to the Fort Belknap Indian Reservation was reserved to American Indians by the treaty establishing the reservation. Although this treaty did not mention water rights, the Court ruled that the federal government, when it created the reservation, intended to deal fairly with American Indians by reserving for them the waters without which their lands would have been useless. Later decisions, citing Winters, established that courts can find federal rights to reserve water for particular purposes if (1) the land in question lies within an enclave under exclusive federal jurisdiction, (2) the land has been formally withdrawn from federal public lands- i.e., withdrawn from the stock of federal lands available for private use under federal land use laws- and set aside or reserved, and (3) the circumstances reveal that the government intended to reserve water as well as land when establishing the reservation.
Some American Indian tribes have also established water rights through the courts based on their traditional diversion and use of certain waters prior to the United States' acquisition of sovereignty. For example, the Rio Grande pueblos already existed when the United States acquired sovereignty over New Mexico in 1848. Although, they at that time became part of the United States, the pueblo lands never formally constituted a part of federal public lands; in any event, no treaty, statute, or executive order has ever designated or withdrawn the pueblos from public lands as American Indian reservations. This fact, however, has not barred application of the Winters doctrine. What constitutes an American Indian reservation is a question of practice, not of legal definition, and the pueblos have always been treated as reservations by the United States. This pragmatic approach is buttressed by Arizona vs. California (1963), wherein the Supreme Court indicated that the manner in which any type of federal reservation is created does not affect the application to it of the Winters doctrine. Therefore, the reserved water rights of Pueblo Indians have priority over other citizens' water rights as of 1848, the year in which pueblos must be considered to have become reservations.

[passage-header]Read the passage and answer the question that follows:[/passage-header]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.

[passage-header]Read the passage and answer the question that follows:
[/passage-header]It was once believed that the brain was independent of metabolic processes occurring elsewhere in the body. In recent studies, however, we have discovered that the production and release in brain neurons of the neurotransmitter serotonin (neurotransmitters are compounds that neurons use to transmit signals to other cells) depend directly on the food that the body processes.
Our first studies sought to determine whether the increase in serotonin observed in rats given a large injection of the amino acid tryptophan might also occur after rats ate meals that change tryptophan levels in the blood. We found that immediately after the rats began to eat, parallel elevations occurred in blood tryptophan, brain tryptophan, and brain serotonin levels. These findings suggested that the production and release of serotonin in brain neurons were normally coupled with blood-tryptophan increases. In later studies, we found that injecting insulin into a rat's bloodstream also caused parallel elevations in blood and brain tryptophan levels and in serotonin levels. We then decided to see whether the secretion of the animal's own insulin similarly affected serotonin production.
We gave the rats a carbohydrate-containing meal that we knew would elicit insulin secretion. As we had hypothesized, the blood tryptophan level and the concentrations of tryptophan and of serotonin in the brain increased after the meal.
Surprisingly, however, when we added a large amount of protein to the meal, brain tryptophan and serotonin levels fell. Since protein contains tryptophan, why should it depress brain tryptophan levels? The answer lies in the mechanism that provides blood tryptophan to the brain cells. This same mechanism also provides the brain cells with other amino acids found in protein, such as tyrosine and leucine. The consumption of protein increases the blood concentration of the other amino acids much more, proportionately, than it does that of tryptophan.
The more protein is in a meal, the lower is the ratio of the resulting blood-tryptophan concentration to the concentration of competing for amino acids, and the more slowly is tryptophan provided to the brain. Thus the more protein in a meal, the less serotonin subsequently produced and released.

[passage-header]Read the passage given below and answer the question that follows. [/passage-header]        According to economic signalling theory, consumers may perceive the frequency with which an unfamiliar brand is advertised as a cue that the brand is of high quality. The notion that (5) highly advertised brands are associated with high-quality products does have some empirical support. Marquardt and McGann found that heavily advertised products did indeed rank high on certain measures of product quality. Because (10) large advertising expenditures represent a significant investment on the part of a manufacturer, only companies that expect to recoup these costs in the long run, through consumers' repeated purchases of the product, (15) can afford to spend such amounts.
        However, two studies by Kirmani have found that although consumers initially perceive expensive advertising as a signal of high brand quality, at some level of spending the manufacturer's (20) advertising effort may be perceived as unreasonably high, implying low manufacturer confidence in product quality. If consumers perceive excessive advertising effort as a sign of a manufacturer's desperation, the result may be less favourable (25) brand perception. In addition, the third study by Kirmani, of print advertisements, found that the use of colour affected consumer perception of brand quality. Because consumers recognise that colour advertisements are more expensive than (30) black and white, the point at which repetition of an advertisement is perceived as excessive comes sooner for a colour advertisement than for a black-and-white advertisement.

[passage-header]Read the passage and answer the question that follows:[/passage-header]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.

[passage-header]Read the passage and answer the question that follows:[/passage-header]After evidence was obtained in the 1920s that the universe is expanding, it became reasonable to ask: Will the universe continue to expand indefinitely, or is there enough mass in it for the mutual attraction of its constituents to bring this expansion to a halt? It can be calculated that the critical density of matter needed to brake the expansion and "close" the universe is equivalent to three hydrogen atoms per cubic meter. But the density of the observable universe-luminous matter in the form of galaxies-comes to only a fraction of this. If the expansion of the universe is to stop, there must be enough invisible matter in the universe to exceed the luminous matter in density by a factor of roughly 70.

Our contribution to the search for this "missing matter" has been to study the rotational velocity of galaxies at various distances from their center of rotation. It has been known for some time that outside the bright nucleus of a typical spiral galaxy luminosity falls off rapidly with distance from the center. If luminosity were a true indicator of mass, most of the mass would be concentrated toward the center. Outside the nucleus, the rotational velocity would decrease geometrically with distance from the center, in conformity with Kepler's law. Instead, we have found that the rotational velocity in spiral galaxies either remains constant with increasing distance from the center or increases slightly. This unexpected result indicates that the fall off in luminous mass with distance from the center is balanced by an increase in nonluminous mass.

Our findings suggest that as much as 90 percent of the mass of the universe is not radiating at any wavelength with enough intensity to be detected on the Earth. Such dark matter could be in the form of extremely dim stars of low mass, of large planets like Jupiter, or of black holes, either small or massive. While it has not yet been determined whether this mass is sufficient to close the universe, some physicists consider it significant that estimates are converging on the critical value.

[passage-header]Read the passage given below and answer the question that follows:[/passage-header]There are recent reports of apparently drastic declines in amphibian populations and of extinctions of a number of the world's endangered amphibian species. 28634These declines, if real, may be signs of a general trend toward extinction, and many environmentalists have claimed that immediate environmental action is necessary to remedy this "94875amphibian crisis," which, in their view, is an indicator of general and catastrophic environmental degradation due to human activity.

To evaluate these claims, it is useful to make a preliminary distinction that is far too often ignored. A declining population should not be confused with an endangered one. An endangered population is always rare, almost always small, and, by definition, under constant threat of extinction even without a   proximate cause in human activities. Its disappearance, however unfortunate, should come as no great surprise. Moreover, chance events - which may indicate nothing about the direction of trends in population size - may lead to its extinction. The probability of extinction due to such random factors depends on the population size and is independent of the prevailing direction of change in that size.

For biologists, population declines are potentially more worrisome than extinctions. Persistent declines, especially in large populations, indicate a changed ecological context. Even here, distinctions must again be made among declines that are only apparent (in the sense that they are part of habitual cycles or of normal fluctuations), declines that take a population to some lower but still acceptable level and those that threaten extinction (e.g by taking the number of individuals below the minimum viable population). Anecdotal reports of population decreases cannot distinguish among these possibilities, and some amphibian populations have shown strong fluctuations in the past. 

It is indisputably true that there is simply not enough long-term scientific data on amphibian populations to enable researchers to identify real declines in amphibian populations. Many fairly common amphibian species declared all but extinct after several declines in the 1950s and 1960s have subsequently recovered, and so might the apparently declining populations that have generated the current appearance of an amphibian crisis. Unfortunately, long-term data will not soon be forthcoming and postponing environmental action while we wait for it may doom species and whole ecosystems to extinction.