Test: Verbal Reasoning (Level 500) - 2 - GMAT MCQ

A. Employees new to customer service as an occupation require training, and an adjustment period, which can result in significant expenses.

This option weakens the suggestion of the Human Resources department by highlighting the potential costs and challenges associated with hiring new employees for customer service. It suggests that hiring additional employees might not be a cost-effective solution, as it would require training and an adjustment period, which can result in significant expenses for the company.

B. In the last 15 years, customer service has made a complete conversion from handling written complaints to dealing with customers solely through electronic mail and telephone calls.

This option does not directly weaken the suggestion of the Human Resources department. It provides information about the transformation of customer service methods but does not specifically address the issue of hiring additional employees or incentivizing current employees.

C. Increasing the satisfaction of customers can be achieved by reducing the amount of time a caller waits on the line before being answered.

This option does not weaken the suggestion of the Human Resources department. It suggests an alternative approach to improving customer satisfaction by reducing wait times, but it does not address the question of hiring additional employees or providing incentives to current employees.

D. A recent experiment showed that when given cash bonuses, customer service employees would answer more customer calls per hour, but the level of customer satisfaction would decrease.

This option directly weakens the suggestion of the Human Resources department. It presents evidence from a recent experiment that shows when employees were given cash bonuses to optimize their performance in terms of call volume, it resulted in increased call volume but decreased customer satisfaction. This suggests that focusing solely on speed and call volume may not lead to improved customer satisfaction.

E. Statistics show that customer service is rated as the most important parameter affecting a customer's decision to recommend a product or service to a peer.

This option does not directly weaken the suggestion of the Human Resources department. It provides information about the importance of customer service in influencing customer recommendations, but it does not address the question of hiring additional employees or providing incentives to current employees.

(A) Most tax revenue collected in Northtown comes from business taxes.

This option does not directly undermine the spokesperson's argument. It simply indicates that business taxes are a significant source of revenue for Northtown. It does not provide any information about the relative tax rates or the business environment in Northtown and Southtown.

(B) Most tax revenue collected in Southtown comes from business taxes.

Similar to option (A), this option does not directly undermine the spokesperson's argument. It suggests that business taxes are a significant source of revenue for Southtown, but it does not provide information about the relative tax rates or the business environment in the two cities.

(C) The net profits generated by Northtown businesses are currently twice those of Southtown businesses.

This option seriously undermines the spokesperson's argument. Despite Southtown's lower business tax rate, if the net profits generated by businesses in Northtown are significantly higher than those in Southtown, it suggests that Northtown may offer a more favorable business environment overall. Higher net profits may compensate for the higher tax rate in Northtown, making the spokesperson's claim less convincing.

(D) Northtown has twice the population of Southtown.

This option does not directly undermine the spokesperson's argument. It provides information about the population size of the two cities, but it does not offer any insights into the tax rates or the business environment. The size of the population alone does not determine the attractiveness of a business environment.

(E) Southtown businesses generate twice as much sales revenue as do Northtown businesses.

This option does not directly undermine the spokesperson's argument. It provides information about the sales revenue generated by businesses in Southtown and Northtown, but it does not provide any information about the tax rates or the profitability of the businesses. Sales revenue alone does not determine the overall business environment or the impact of tax rates on businesses.

(A) Most jurors are less likely to understand instructions given in convoluted, legalistic language than instructions given in simple, easily comprehensible language. This statement supports the lawyer's argument by highlighting the difficulty jurors have in understanding convoluted language. It strengthens the argument.

(B) Most jurors do not have an adequate understanding of their role after being given jury instructions in convoluted, legalistic language. This statement supports the lawyer's argument by suggesting that convoluted language fails to provide jurors with an adequate understanding of their role. It strengthens the argument.

(C) Jury instructions formulated in simple, easily comprehensible language can adequately describe the role of the jurors. This statement directly supports the lawyer's argument by stating that simple language can adequately describe the jurors' role. It strengthens the argument.

(D) The details of the role of the jurors cannot be specified with complete precision in simple, easily comprehensible language. This statement weakens the lawyer's argument because it suggests that simple language may not be able to convey the precise details of the jurors' role. It does not support the argument.

(E) Jurors do not need to know the precise details of their role in order to have an adequate understanding of that role. This statement supports the lawyer's argument by asserting that a basic understanding of the jurors' role is adequate, without requiring precise details. It strengthens the argument.

Therefore, the answer is (D) The details of the role of the jurors cannot be specified with complete precision in simple, easily comprehensible language.

A) An employee of the Central Intelligence Agency reveals classified information to a foreign government. This example does not align with the argument because revealing classified information to a foreign government is not an act that advances the public interest in honest government and the rule of law. It involves unauthorized disclosure of sensitive information.

B) A movie star loses popularity because a studio employee tells a magazine about the star's troubled personal life. This example is unrelated to government employees and their role in advancing the public interest in honest government and the rule of law. It does not align with the argument.

C) An energy company’s stock plunges after an employee publicizes its accounting records. This example does not involve government employees or their role in advancing the public interest in honest government and the rule of law. It is unrelated to the argument.

D) A prominent plastic surgeon loses her license after an employee sues her for malpractice after she operates on him. This example does not involve government employees or the public interest in honest government and the rule of law. It is unrelated to the argument.

E) A Congressional aide reveals cases of bribery in the House of Representatives. This example aligns with the argument as it involves a government employee (a Congressional aide) bringing to light cases of bribery in the House of Representatives. It demonstrates the importance of protecting employees who disclose information that advances the public interest in honest government and the rule of law.

Therefore, the best example for the argument above is (E) A Congressional aide reveals cases of bribery in the House of Representatives.

The passage is primarily concerned with discussing the:

(B) role of the synthesis and degradation of mRNA in cell functioning

Explanation:

The passage explores how the concentration of mRNA in a cell is influenced by both its synthesis and degradation rates. It emphasizes that recent investigations have revealed the importance of mRNA degradation rates in addition to synthesis rates in regulating protein production. The example of red blood cell development illustrates how cells manage both mRNA synthesis and degradation to control protein levels effectively.

• (A) is incorrect because the passage uses red blood cells as an example but does not primarily focus on their development or the influence of mRNA concentrations on this process.
• (C) is incorrect as the passage does not discuss the mechanism of gene transcription into mRNA.
• (D) is incorrect because the passage does not focus on differences in mRNA concentrations between the nucleus and the cytoplasm.
• (E) is incorrect because the passage does not address how mRNA synthesis contributes to the onset of diabetes.

Thus, the passage's central theme is the role of mRNA synthesis and degradation in regulating cell functioning, making (B) the best answer.

The passage suggests that a biologist who held the view described in the first sentence of the second paragraph would most probably also have believed:

(A) The rate of degradation of specific mRNA’s has little effect on protein concentrations.

Explanation:

The first sentence of the second paragraph states that biologists previously believed the variable rates of mRNA synthesis determined the quantities of mRNA and their corresponding proteins in a cell. This view implies that they did not consider the degradation rates of mRNA to be a significant factor in protein concentrations.

• (A) is correct because it aligns with the outdated belief that degradation rates were not seen as crucial in determining protein concentrations, which contrasts with the newer understanding that degradation rates are actually important.

• (B) is incorrect because the previous belief did not emphasize the need to study degradation rates intensively; rather, it underestimated their importance.

• (C) is incorrect because the previous belief did not suggest that synthesis and degradation rates for any given mRNA are normally equal.

• (D) is incorrect because the previous belief did not address varying degradation rates for different mRNA’s; it focused on synthesis rates.

• (E) is incorrect because the passage does not suggest that most mRNA’s degrade very rapidly. Instead, it highlights that degradation rates can vary and affect mRNA concentrations.

Therefore, (A) accurately reflects the notion that, under the previous view, degradation rates were considered less important in affecting protein concentrations.

The best description of the relationship between the second and third paragraphs of the passage is:

(C) The third paragraph describes a specific case of a phenomenon that is described generally in the second paragraph.

Explanation:

The second paragraph discusses the general shift in understanding regarding the regulation of mRNA concentrations, highlighting that degradation rates of mRNA, rather than just synthesis rates, play a crucial role in determining mRNA levels and, consequently, protein levels.

The third paragraph provides a specific example of this phenomenon by describing how red blood cell development involves the regulation of mRNA synthesis and degradation to control the levels of hemoglobin, illustrating the general principle discussed in the second paragraph.

• (A) is incorrect because the second and third paragraphs are not opposing theories; instead, the third paragraph provides an example of the phenomenon described in the second paragraph.

• (B) is incorrect because both paragraphs discuss the role of mRNA degradation in regulating protein synthesis, with the third paragraph providing a specific example rather than describing a new or replaced view.

• (D) is incorrect because the third paragraph does not describe an investigation related to resolving problems raised by the phenomena in the second paragraph but rather provides an example of the concept discussed.

• (E) is incorrect because the second paragraph discusses the general phenomenon of mRNA degradation affecting protein concentrations, while the third paragraph focuses on a specific example (red blood cell development) rather than providing another specific example of the general phenomenon.

Therefore, (C) accurately captures how the third paragraph illustrates a specific case related to the general phenomenon introduced in the second paragraph.

The accumulation of concentrations of hemoglobin in red blood cells is mentioned in the passage as an example of:

(A) The effectiveness of simultaneous variation of the rates of synthesis and degradation of mRNA.

Explanation:

The passage explains that the development of red blood cells illustrates how cells regulate protein production by both halting the synthesis of certain mRNAs and rapidly degrading those mRNAs. This process ensures that the cells accumulate the necessary concentrations of hemoglobin while reducing other proteins.

• (A) is correct because the example of red blood cells specifically demonstrates the effectiveness of managing both mRNA synthesis and degradation to regulate the production of a crucial protein, hemoglobin.

• (B) is incorrect because the ribosome’s role is not the focus of the example. The passage emphasizes mRNA regulation rather than ribosomal function.

• (C) is incorrect because the passage does not focus on the timing of gene activation but on how mRNA synthesis and degradation affect protein levels.

• (D) is incorrect because the example does not address abnormal proliferation or cancer but rather the normal process of hemoglobin accumulation through regulated mRNA management.

• (E) is incorrect because the example is not evidence supporting an obsolete view but rather illustrates the current understanding of mRNA regulation.

Thus, (A) accurately captures how the example of hemoglobin accumulation in red blood cells illustrates the principle of regulating protein production through both mRNA synthesis and degradation.

(A) According to some linguists, many of the world's languages can be tracked back to a common source known as Indo-European. However, Indo-European cannot be the earliest language for if it were, then there would be no language from which it was derived. But this is highly unlikely, given the overwhelming evidence that humans spoke long before the advent of Indo-European. This argument does not follow the same pattern of reasoning as the given argument. It presents a counter-argument based on the premise that if Indo-European were the earliest language, there would be no language from which it was derived. It does not involve an infinite regress.

(B) The claim that any scientific theory is adequate as long as it agrees with all the empirical data cannot be correct. For there are an infinite number of theories all of which account equally well for the empirical data, and they cannot all be true at the same time. This argument follows a similar pattern of reasoning. It claims that the given claim is incorrect because it would lead to a problem with an infinite number of theories, which cannot all be true at the same time. It involves an infinite regress-like problem, similar to the given argument.

(C) Some historians claim that no theory is ever genuinely new; no matter how clever a theory is, there is always a precedent theory that contains its gist. But if this were true, then every theory would have a precedent theory that contains its gist, and this precedent theory would have a precedent theory, and so on, without end. Since this is clearly impossible, the historians' claim must be false. This argument follows a similar pattern of reasoning. It argues against the historians' claim by pointing out that it would lead to an infinite regress, which is deemed impossible. It involves the same type of reasoning as the given argument.

(D) Some engineers define a structure's foundation as that part of the structure that supports the rest of the structure. This definition is unfortunate, however, because it evokes the suggestion that the foundation itself does not have any support, which, of course, is absurd. This argument does not follow the same pattern of reasoning. It presents a definition and claims that it evokes an absurd suggestion, without involving an infinite regress.

(E) Some people claim that the first library was the library of Alexandria, which for many centuries contained the largest collection of books in the world. However, Alexandria's collection was itself put together from smaller collections, small libraries in themselves. It follows that the library of Alexandria was not the first in the world. This argument does not follow the same pattern of reasoning. It presents evidence that challenges the claim about the first library by pointing out that Alexandria's collection was compiled from smaller collections. It does not involve an infinite regress.

Based on the evaluation, the argument that is most similar in its pattern of reasoning to the given argument is (C) Some historians claim that no theory is ever genuinely new; no matter how clever a theory is, there is always a precedent theory that contains its gist. But if this were true, then every theory would have a precedent theory that contains its gist, and this precedent theory would have a precedent theory, and so on, without end. Since this is clearly impossible, the historians' claim must be false.

(A) The amount of art supplies used in any of the Aesthetic Institute’s 25 classes is directly proportional to the number of students in that class. Since in these classes the institute enrolled 20 percent more students overall last year than in the previous year, more art supplies were used in the institute’s classes last year than in the previous year. This argument follows a similar pattern of reasoning. It states that the amount of art supplies used is directly proportional to the number of students and concludes that more supplies were used due to a 20 percent increase in the number of students.

(B) The number of courses in painting offered by the Aesthetic Institute in any term is directly proportional to the number of students enrolled in the institute in that term. But the institute offers the same number of courses in sculpture each term. Hence, the institute usually offers more courses in painting than in sculpture each term. This argument does not follow the same pattern of reasoning. It establishes a relationship between the number of courses in painting and the number of students but concludes that the institute usually offers more courses in painting based on the fact that the number of sculpture courses remains the same. It does not involve a change in one variable leading to a conclusion about the change in another variable.

(C) The number of new students enrolled at the Aesthetic Institute in any given year is directly proportional to the amount of advertising the institute has done in the previous year. Hence, if the institute seeks to increase its student body, it must increase the amount it spends on advertising. This argument establishes a relationship between the number of new students and the amount of advertising, but it does not involve a change in one variable leading to a conclusion about the change in another variable. It does not follow the same pattern of reasoning.

(D) The fees paid by a student at the Aesthetic Institute are directly proportional to the number of classes in which that student enrolls. Since the number of students at the Aesthetic Institute is increasing, it follows that the institute is collecting a greater amount in fees paid by students than it used to. This argument follows a similar pattern of reasoning. It states that fees paid by a student are directly proportional to the number of classes and concludes that the institute is collecting a greater amount in fees due to an increase in the number of students.

(E) The number of instructors employed by the Aesthetic Institute in any term is directly proportional to the number of classes offered in that term and also directly proportional to the number of students enrolled at the institute. Thus, the number of classes offered by the institute in any term is directly proportional to the number of students enrolled in that term. This argument establishes relationships between the number of instructors, the number of classes, and the number of students. It does not involve a change in one variable leading to a conclusion about the change in another variable. It does not follow the same pattern of reasoning.

Based on the evaluation, the argument that has a pattern of reasoning most similar to the one in the given argument is (A) The amount of art supplies used in any of the Aesthetic Institute’s 25 classes is directly proportional to the number of students in that class. Since in these classes, the institute enrolled 20 percent more students overall last year than in the previous year, more art supplies were used in the institute’s classes last year than in the previous year.

Option (A) fails to consider that there might be extraterrestrial forms of intelligence that are not living beings.

This option does not accurately describe the flaw in the argument's reasoning. The argument does not address the possibility of extraterrestrial forms of intelligence that are not living beings. The flaw lies in the argument's assumption that the absence of evidence for intelligent extraterrestrial life is evidence against its existence, rather than considering alternative possibilities.

Option (B) confuses an absence of evidence for a hypothesis with the existence of evidence against the hypothesis.

This option accurately describes the flaw in the argument's reasoning. The argument assumes that because there is no evidence of intelligent extraterrestrial life, it is evidence against the existence of such life. However, the absence of evidence does not necessarily prove the non-existence of something. It is possible that evidence has not yet been discovered or that the methods used to search for it have been insufficient.

Option (C) interprets a disagreement over a scientific theory as a disproof of that theory.

This option does not accurately describe the flaw in the argument's reasoning. The argument does not involve a disagreement over a scientific theory. It is focused on the absence of evidence and making a conclusion based on that absence.

Option (D) makes an inference that relies on the vagueness of the term "life."

This option does not accurately describe the flaw in the argument's reasoning. The argument does not rely on the vagueness of the term "life" in making its conclusion. It is concerned with the absence of evidence for intelligent extraterrestrial life and drawing a conclusion based on that absence.

Option (E) relies on a weak analogy rather than on evidence to draw a conclusion.

This option does not accurately describe the flaw in the argument's reasoning. The argument does not rely on an analogy to draw its conclusion. It is based on the absence of evidence for intelligent extraterrestrial life and making a conclusion based on that absence.

In summary, option (B) is the most accurate description of the flaw in the argument's reasoning, as it correctly identifies the confusion between the absence of evidence and evidence against a hypothesis.

(C) It rejects an argument merely on the grounds that the arguer has not behaved in a way that is consistent with the argument.

In the argument, the politician dismisses Kuyler's argument because Kuyler's company has had numerous lucrative contracts with the government, which contradicts the implication that entering into a contract with the government would be improper. However, this is a flawed approach because it rejects Kuyler's argument solely based on Kuyler's behavior or past actions, rather than addressing the merits of the argument itself. The fact that Kuyler's company has had contracts with the government does not automatically render Kuyler's argument invalid or irrelevant. The argument should be evaluated based on its own reasoning and evidence, rather than being dismissed solely due to the perceived inconsistency with the arguer's behavior.

The passage discusses how regulations related to oil well drilling have often lagged behind the actual practices, leading to environmental issues like groundwater contamination. It explains that:

• Historical Regulations: Early regulations focused on protecting oil reserves rather than groundwater, leading to unexpected contamination of drinking water wells.

• Current Issues: Even with modern safeguards like metal casings and cement, the long-term effectiveness and potential hazards (e.g., corrosion, bacteria, vibrations) remain uncertain.

• Continued Risk: New problems arise due to insufficient knowledge, such as the recent disaster due to poor geological understanding, indicating ongoing risks and the need for better research.

Therefore, (D) accurately captures the passage's central message that environmental contamination persists due to inadequate and reactive regulation based on limited scientific understanding.

The passage states that:

(E) They are generally found at greater depths than groundwater formations.

Explanation:

In the passage, it is mentioned that groundwater is typically located in porous and permeable geologic formations near the earth’s surface, whereas petroleum and unpotable saline water reservoirs are generally found in similar types of formations but at greater depths. This indicates that oil reservoirs are located deeper than groundwater formations.

Here's how the other options compare:

• (A) They are usually located in areas whose subsurface geology is poorly understood.
  The passage does not specifically mention that oil reservoirs are usually located in areas with poorly understood subsurface geology, although it does highlight issues with geological understanding.

• (B) They are generally less common in coastal regions.
  The passage does not address the commonality of oil reservoirs in coastal regions.

• (C) They are usually located in geologic formations similar to those in which gas is found.
  The passage mentions that oil and saline water reservoirs are generally found in similar formations, but it does not specify that these formations are similar to those where gas is found.

• (D) They are often contaminated by fresh or saline water.
  The passage does not state that oil reservoirs are often contaminated by fresh or saline water; rather, it describes how drilling can lead to groundwater contamination.

Thus, the best choice based on the passage is (E), which accurately reflects the information provided about the relative depths of oil reservoirs and groundwater formations.

The author's attitude regarding oil well drilling regulations can most accurately be described as:

(C) concerned that regulatory reform will not progress until significant undesirable events occur.

Explanation:

The passage discusses how the regulation of oil well drilling has historically lagged behind scientific understanding, often only addressing issues after undesirable events, such as groundwater contamination, have occurred. The author highlights that regulations have typically been reactive rather than proactive and points out ongoing concerns about the adequacy of current regulations and the persistent risks due to insufficient knowledge.

Here's why the other options are less accurate:

• (A) cynical that future regulatory reform will occur without international concern
  The passage does mention international concern but does not convey a general cynicism about future reforms.

• (B) satisfied that existing regulations are adequate to prevent unwarranted tradeoffs between resource collection and environmental protection
  The passage indicates ongoing issues and hazards with existing regulations, suggesting dissatisfaction rather than satisfaction.

• (D) optimistic that current scientific research will spur regulatory reform
  The passage does not express optimism about current research leading to reform; rather, it suggests that regulations often follow undesirable events and are still inadequate.

• (E) confident that regulations will eventually be based on accurate geologic understandings
  The passage does not show confidence in future regulations being based on accurate geologic understanding. Instead, it reflects concerns about inadequate understanding and ongoing risks.

Thus, the best choice reflecting the author's attitude is (C), which accurately captures the concern that regulatory progress often lags behind actual events and scientific understanding.

The passage discusses how scientific knowledge about the environmental impacts of oil well drilling has often been inadequate, leading to unforeseen problems. Specifically, it mentions that the long-term stability of protective measures, like casing and cement used to prevent groundwater contamination, is unknown due to insufficient understanding of the complex interactions between drilling operations and geologic formations. This reflects a broader issue of not fully understanding the consequences of drilling in various geologic contexts.

Here’s why the other options are less accurate:

• (A) a lack of understanding regarding the dangers to human health posed by groundwater contamination
  The passage does mention the contamination of groundwater, but the primary focus of “the hazards of insufficient knowledge” is on the broader issues of drilling and geologic interactions, not specifically on human health dangers.

• (C) poorly tested methods for verifying the safety of newly developed technologies
  The passage does not primarily discuss the testing of new technologies but rather the general inadequacy of scientific knowledge and its implications.

• (D) an inadequate appreciation for the difficulties of enacting and enforcing environmental regulations
  While the passage touches on regulatory issues, the phrase “the hazards of insufficient knowledge” more directly addresses the scientific understanding of drilling impacts rather than regulatory enforcement challenges.

• (E) a rudimentary understanding of the materials used in manufacturing metal pipe casings
  The passage mentions materials used in casings, but the broader issue is the lack of understanding of the geological and environmental impacts, not just the materials themselves.

Therefore, (B) best captures the main issue conveyed by the author, focusing on the failure to grasp the potential consequences of drilling in complex geologic systems.

(A) The committal of public funds for new scientific research will ensure that the public welfare will be enhanced. This option does not accurately express the main point of the argument. The argument does not claim that committing public funds for scientific research will ensure enhancement of the public welfare. Instead, it argues against the refusal to commit funds based on the lack of assurance of specific outcomes.

(B) If it were possible to predict the general outcome of a new scientific research effort, then legislators would not refuse to commit public funds for that effort. This option does not accurately express the main point of the argument. The argument acknowledges that predicting the specific outcomes of scientific research is difficult and argues against refusal to fund research based on this lack of predictability. However, the argument does not directly address the possibility of predicting general outcomes.

(C) Scientific discoveries that have contributed to the public welfare would have occurred sooner if public funds had been committed to the research that generated those discoveries. This option does not accurately express the main point of the argument. The argument does not focus on the timing of scientific discoveries or make a claim about the acceleration of these discoveries with public funding. Instead, it emphasizes the unpredictability of specific outcomes and argues against the refusal to fund research based on this unpredictability.

(D) In order to ensure that scientific research is directed toward contributing to the public welfare, legislators must commit public funds to new scientific research. This option does not accurately express the main point of the argument. While the argument advocates for the commitment of public funds to scientific research despite the lack of guarantees, it does not claim that this commitment is necessary to ensure that research is directed towards the public welfare. The argument emphasizes the serendipitous nature of scientific discoveries.

(E) Lack of guarantees that new scientific research will contribute to the public welfare is not sufficient reason for legislators to refuse to commit public funds to new scientific research. This option accurately expresses the main point of the argument. The argument challenges the position of legislators who refuse to allocate public funds for scientific research due to the lack of assurance of specific outcomes. It argues that this lack of guarantees should not be a sufficient reason to deny funding, as unexpected and significant contributions to the public welfare can emerge from scientific research.

Therefore, option (E) is the most accurate expression of the main point of the argument.

A. The price of ice cream will go up in the future: This option suggests that the investment in the ice-cream maker was a good one because the price of ice cream is expected to increase in the future. However, this reasoning is not explicitly stated or implied in the paragraph, so it does not logically complete the thought.

B. He has purchased the ice-cream maker for the convenience of having it available if and when he needs it: This option aligns with the idea of justifying the investment in the ice-cream maker despite its infrequent use. It suggests that the value of the purchase lies in the convenience of having the ice-cream maker accessible for future occasions when it may be needed. This option completes the thought in a logical and relevant manner.

C. In a society that is oriented toward consumer goods, one should take every opportunity to acquire things: This option presents a broader perspective on consumer behavior and suggests that acquiring things is important in a society focused on consumer goods. However, this idea does not directly address or support the reasoning behind the brother's justification for the investment in the ice-cream maker.

D. Today $25 is not worth what it was two years ago on account of the inflation rate: This option introduces the concept of inflation and suggests that the value of $25 has decreased over time. However, this reasoning does not directly relate to the brother's justification for the investment in the ice-cream maker.

E. By using it so infrequently, he has conserved a considerable amount of electrical energy: This option focuses on the energy-saving aspect of infrequently using the ice-cream maker. While it highlights a positive outcome of the brother's behavior, it does not directly address or support his justification for the investment.

Among the options provided, option B is the best completion because it aligns with the brother's perspective on the value of the ice-cream maker based on convenience and availability.

A. Low-income residents of Workney will continue to ride the buses in the same numbers despite the fare increase.

This assumption suggests that the fare increase will not significantly impact the ridership of low-income residents. If they continue to ride the buses in the same numbers, it supports the feasibility of the alternative proposal.

B. Low-income riders would be more likely to take advantage of the savings afforded by the 9-token offer than would other riders.

This assumption implies that low-income riders are more price-sensitive and would be more inclined to take advantage of the cost-saving opportunity provided by the 9-token offer. It suggests that the alternative proposal would be beneficial specifically for low-income riders.

C. The outlay of $10.00 for the purchase of 9 fare tokens would not be prohibitive for low-income bus riders.

This assumption is crucial for the alternative proposal to be a viable option for low-income riders. It suggests that the cost of purchasing 9 fare tokens for $10.00 would not impose a significant financial burden on low-income bus riders.

D. The proposed fare increase is needed for the purchase of new buses for the city's bus system.

This assumption suggests that the fare increase is necessary to generate additional revenue for the city's bus system, potentially to fund the purchase of new buses. It implies that the fare increase is justified and serves a specific purpose.

E. Buses provide the only means of public transportation in the city of Workney.

This assumption implies that the bus system is the primary mode of public transportation in Workney and that alternative transportation options are limited or nonexistent. It underscores the importance of addressing the fare increase issue for low-income residents who heavily rely on buses for their transportation needs.

It's important to note that while all of these assumptions play a role in evaluating the alternative proposal, the strongest assumption that directly supports the feasibility of the alternative proposal is option C.

The passage discusses the impact of changes in atmospheric CO2 levels on climate and plant growth. Specifically, it describes a feedback mechanism where increased CO2 levels, possibly due to forest fires or volcanic activity, lead to a warmer climate. This warming promotes plant growth, which in turn absorbs more CO2, eventually cooling the climate again. This process creates a potential long-term oscillation in CO2 levels and temperature.

Here’s why the other options are less accurate:

• (A) Why are projections of the effects of changes in water vapor levels on the climate so inaccurate?
  The passage does mention the effects of changes in water vapor, but it does not discuss why projections about these effects are inaccurate.

• (B) What are the steps in the process that takes place as CO2 absorbs long-wavelength radiation?
  The passage explains the greenhouse effect, including how CO2 absorbs and remits long-wavelength radiation, but it does not detail the step-by-step process.

• (C) How might our understanding of the greenhouse effect be improved if the burning of fossil fuels were decreased?
  The passage discusses the current effects of burning fossil fuels on CO2 levels and temperature but does not address how decreasing fossil fuel use would improve understanding of the greenhouse effect.

• (E) Why are there fewer meteorological recording stations in the Southern Hemisphere oceanic zone than elsewhere?
  The passage mentions the distribution of meteorological stations and possible implications for temperature measurements but does not provide reasons for the differences in station numbers.

Thus, (D) is the most accurate choice because it directly addresses the passage’s discussion of the cyclical nature of CO2 levels and temperature changes.

The passage focuses on the relationship between CO2 levels and climate change. It explains how CO2 affects climate through the greenhouse effect, discusses potential outcomes of varying CO2 levels, and describes a feedback mechanism involving CO2 and temperature oscillations. The author details how increased CO2 can lead to warming and how subsequent plant growth might affect CO2 levels and temperature.

Here’s why the other options are less accurate:

• (A) Explaining the effects that the burning of fossil fuels might have on climate
  While the passage mentions the impact of burning fossil fuels on CO2 levels and global temperatures, its primary focus is on the broader effects of CO2 changes on climate rather than solely on fossil fuel effects.

• (B) Illustrating the effects of CO2 on atmospheric radiation
  The passage does illustrate the effects of CO2 on atmospheric radiation, but it also covers broader implications for climate and temperature changes, not just radiation effects.

• (D) Challenging hypotheses about the effects of water vapor and CO2 on climate
  The passage does not specifically challenge hypotheses; it presents information on how changes in CO2 levels affect climate and acknowledges different theories but does not critique them.

• (E) Refuting hypotheses by climatologists about the causes of global temperature fluctuations
  The passage does not aim to refute specific hypotheses but discusses various theories and observations related to CO2 levels and climate.

Thus, (C) is the most accurate choice as it reflects the passage's primary focus on the effects of CO2 level changes on climate.

The passage explains that CO2 plays a significant role in the greenhouse effect by absorbing long-wavelength radiation and re-radiating it towards the Earth's surface, thus contributing to warming. It also notes that a reduction in atmospheric CO2 would lead to a decrease in surface temperatures. The passage references theories suggesting that halving the CO2 concentration could lead to dramatic cooling, such as the Earth becoming completely covered with ice or experiencing a 3℃ reduction in global temperatures.

Thus, the passage implies that reducing CO2 levels will have a cooling effect, leading to a decrease in global temperatures. This makes (A) the most accurate answer as it aligns with the described impact of reducing CO2.

The other options do not directly reflect the passage's content:

• (B) at the most a slight increase in short-wavelength radiation reaching the Earth
  The passage does not discuss an increase in short-wavelength radiation due to CO2 changes; rather, it focuses on the impact on temperature.

• (C) a slight long-term increase in global temperatures
  A decrease in CO2 would generally lead to a decrease in temperatures, not an increase.

• (D) a large long-term increase in the amount of volcanic activity
  The passage does not connect CO2 decrease with an increase in volcanic activity.

• (E) a slight short-term increase in atmospheric water vapor content
  There is no direct link in the passage between a decrease in CO2 and an increase in water vapor content.

Therefore, (A) is the most fitting choice based on the passage's information.

In the passage, Venus is mentioned as an extreme example of the greenhouse effect. The author uses Venus to illustrate the profound impact that high levels of CO2 can have on a planet's surface temperature. Venus, with its thick CO2-rich atmosphere, experiences extremely high surface temperatures due to the greenhouse effect. This example underscores the significant role that CO2 plays in regulating planetary temperatures, thereby supporting the argument that CO2 levels have a major effect on climate.

Here's why the other options are less suitable:

• (A) show the inherent weakness of the greenhouse effect theory
  The reference to Venus actually supports the greenhouse effect theory by providing a clear example of its impact, rather than showing its weakness.

• (B) show that the greenhouse effect works on other planets but not on Earth
  The passage does not suggest that the greenhouse effect does not work on Earth; it rather illustrates its significant impact on other planets to emphasize its relevance to Earth.

• (C) show the extent to which Earth’s atmosphere differs from that of Venus
  While the passage does mention differences, the primary purpose of mentioning Venus is to illustrate the greenhouse effect, not to compare atmospheric differences in detail.

• (D) support the contention that as water vapor increases, the amount of CO2 increases
  The passage does not claim a direct relationship between water vapor increases and CO2 levels. It focuses on the impact of CO2 on temperature rather than a direct link between CO2 and water vapor.

Therefore, (E) is the most accurate answer as it aligns with the use of Venus to highlight the significant effect of CO2 on climate.