问答

1答疑

[Problem Solving]

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题目：

Machines X and Y run at different constant rates, and machine X can complete a certain job in 9 hours. Machine X worked on the job alone for the first 3 hours and the two machines, working together, then completed the job in 4 more hours. How many hours would it have taken machine Y, working alone, to complete the entire job?

选项:

A、18
B、
C、
D、
E、

答案:

A
1答疑

[Data Sufficiency]

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题目：

Is –3 ≤ x ≤ 3 ?
  1. x 2 + y 2 = 9
  2. x 2 + y ≤ 9

选项:

A、Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B、Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C、BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D、EACH statement ALONE is sufficient.
E、Statements (1) and (2) TOGETHER are NOT sufficient.

答案:

A
1答疑

[Critical Reasoning]

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题目：

Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants. Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Possibly, therefore, the herb's high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.

选项:

A、histidine is found in all parts of the plant-roots, stem, leaves, and flowers
B、the herb's high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C、others of the closely related group of plants are also found to produce histidine in large quantities
D、cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E、the concentration of histidine in the growing herb declines as the plant approaches maturity

答案:

C
1答疑

[Sentence Correction]

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题目：

Having finally reached a tentative labor agreement with its company's pilots, it must now be determined by the airline's board of directors how the airline can both increase profits and compete more effectively for customers than they did in the past.

选项:

A、 it must now be determined by the airline's board of directors how the airline can both increase profits and compete more effectively for customers than they did in the past
B、 it must now be determined by the airline's board of directors how the airline can both increase profits and must compete more effectively than in the past for customers
C、 the airline's board of directors must now determine both how to make the airline increase profits and compete more effectively for customers than they did in the past
D、 the airline's board of directors must now determine how the airline can both increase profits and compete more effectively for customers than it did in the past
E、 the airline's board of directors must now determine how the airline can both increase profits and also how to make it compete more effectively than in the past for customers

答案:

D
1答疑

[Graphics Interpretation]

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题目：

During the first week of April, the ChefZ cooking pan was out of stock at Online Retailer X. Day 1 shoppers are those shoppers who came to Online Retailer X's website seeking a ChefZ cooking pan. For each of the first 3 days of that week, the graph shows the subsequent behavior of all the Day 1 shoppers who visited Online Retailer X's website seeking ChefZ. Shoppers who came to the website and purchased a different item in lieu of ChefZ paid an average of 25% more for the item.

From each drop-down menu, select the option that creates the most accurate statement based on the information provided.

选项:

% of Day 1 shoppers visited the site on Day 3.

Shoppers at Online Retailer X who purchased substitute items on Day 1 and Day 2 paid a total amount that was approximately% of the total all Day 1 shoppers would have paid had each of them been able to purchase ChefZ on Day 1.

答案:

B C
1答疑

[Data Sufficiency]

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题目：

How many integers n are there such that r < n < s ?
  1. s − r = 5
  2. r and s are not integers.

选项:

A、Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B、Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C、BOTH statements (1) and (2) TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D、EACH statement ALONE is sufficient.
E、Statements (1) and (2) TOGETHER are not sufficient.

答案:

C
1答疑

[Reading Comprehension]

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文章：

    The term "episodic memory" was introduced by Tulving to refer to what he considered a uniquely human capacity-the ability to recollect specific past events, to travel back into the past in one's own mind-as distinct from the capacity simply to use information acquired through past experiences. Subsequently, Clayton et al. developed criteria to test for episodic memory in animals. According to these criteria, episodic memories are not of individual bits of information; they involvemultiple components of a single event "bound" together. Clayton sought to examine evidence of scrub jays' accurate memory of "what," "where," and "when" information and their binding of this information. In the wild, these birds store food for retrieval later during periods of food scarcity. Clayton's experiment required jays to remember the type, location, and freshness of stored food based on a unique learning event. Crickets were stored in one location and peanuts in another. Jays prefer crickets, but crickets degrade more quickly. Clayton's birds switched their preference from crickets to peanuts once the food had been stored for a certain length of time, showing that they retain information about the what, the where, and the when. Such experiments cannot, however, reveal whether the birds were reexperiencing the past when retrieving the information. Clayton acknowledged this by using the term "episodic-like" memory.

题目：

It can be inferred that the author of the passage and Clayton would both agree that

选项:

A、the food preferences of the scrub jays in Clayton's experiment are difficult to explain
B、the presence of episodic memory cannot be inferred solely on the basis of observable behavior
C、Clayton's experiment demonstrated that scrub jays do not reexperience the past but do exhibit episodic-like memory
D、Tulving substantially underestimated the ability of animals to bind different kinds of information
E、Clayton's experiment had certain fundamental design flaws that make it difficult to draw any conclusions about scrub jay's memories

答案:

B
1答疑

[Critical Reasoning]

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题目：

Some anthropologists study modern-day societies of foragers in an effort to learn about our ancient ancestors who were also foragers. A flaw in this strategy is that forager societies are extremely varied. Indeed, any forager society with which anthropologists are familiar has had considerable contact with modern, non-forager societies.

Which of the following, if true, would most weaken the criticism made above of the anthropologists' strategy?

选项:

A、All forager societies throughout history have had a number of important features in common that are absent from other types of societies.
B、Most ancient forager societies either dissolved or made a transition to another way of life.
C、All anthropologists study one kind or another of modern-day society.
D、Many anthropologists who study modern-day forager societies do not draw inferences about ancient societies on the basis of their studies.
E、Even those modern-day forager societies that have not had significant contact with modern societies are importantly different from ancient forager societies.

答案:

A
1答疑

[Critical Reasoning]

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题目：

According to a study, after a week of high-altitude living, twenty men had slimmed down. The men, middle-aged residents of low-altitude areas, had been taken to a research station at 2,650 meters (8,694 feet) above sea level. They had unrestricted access to food and were forbidden vigorous exercise, yet they lost an average of 1.5 kilograms (3.3 pounds) during their one-week stay. Clearly, the lower availability of oxygen at higher altitudes, or hypobaric hypoxia, can be said to have caused the weight loss, since __________.

Which of the following would, if true, most logically complete the argument?

选项:

A、a decrease in oxygen intake has been shown to depress appetite
B、the men all participated in the same kinds of exercise during their stay
C、the foods available to the men had fewer calories than the foods they usually ate
D、exercise at higher altitudes is more difficult than exercise at lower altitudes is
E、several weeks after returning home, the men still weighed less than they had before the study

答案:

A
1答疑

[Critical Reasoning]

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题目：

Aroca City currently funds its public schools through taxes on property. In place of this system, the city plans to introduce a sales tax of 3 percent on all retail sales in the city. Critics protest that 3 percent of current retail sales falls short of the amount raised for schools by property taxes. The critics are correct on this point. Nevertheless, implementing the plan will probably not reduce the money going to Aroca's schools. Several large retailers have selected Aroca City as the site for huge new stores, and these are certain to draw large numbers of shoppers from neighboring municipalities, where sales are taxed at rates of 6&nbsp;percent and more. In consequence, retail sales in Aroca City are bound to increase substantially.

In the argument given, the two portions in boldface play which of the following roles?

选项:

A、
A. The first presents a plan that the argument concludes is unlikely to achieve its goal; the second expresses that conclusion.
B、
B. The first presents a plan that the argument concludes is unlikely to achieve its goal; the second presents evidence in support of that conclusion.
C、
C. The first presents a plan that the argument contends is the best available; the second is a conclusion drawn by the argument to justify that contention.
D、
D. The first presents a plan one of whose consequences is at issue in the argument; the second is the argument's conclusion about that consequence.
E、
E. The first presents a plan that the argument seeks to defend against a certain criticism; the second is that criticism.

答案:

D
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1142浏览

[Undefined]

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Art historian: Unlike many artistic traditions that sought to depict plants native to the local area in a seasonally appropriate way (for example, depicting scenes of spring with the plants in the appropriate stages of development for that season), seventeenth-century Dutch artists specializing in flower paintings almost exclusively chose to depict exotic species of flowers from outside the local area. Painting such species was worthwhile primarily because the art-buying public had developed a strong preference for images of the exotic. The great botanical centers of the time gave the artists direct access to such flowers, which the artists would freely combine in a single painting, regardless of whether the combined species occurred together in the wild, and depicted each in full bloom, regardless of whether those species bloomed at the same time in nature.

Statement: The art historian makes the point that the species of flowers these Dutch artists chose to paint were 1 largely because the species were 2 .

Select for 1 and for 2 the options that complete the statement so that it is most strongly supported by the information provided. Make only two selections, one in each column.
我选的CE，和EC有什么区别？怎么选出EC的？
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3255浏览

[Undefined]

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An unusually severe winter occurred in Europe after the continent was blanketed by a blue haze resulting from the eruption of the Laki Volcano in the European republic of Iceland in the summer of 1984.  Thus, it is evident that major eruptions cause the atmosphere to become cooler than it would be otherwise.
Which of the following statements, if true, most seriously weakens the argument above?
C选项为什么就不会有张冠李戴的问题呢，1984和1982的气候情况能一样吗，C里的火山就可以试用于原文的火山吗
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3609浏览

[Undefined]

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The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
为什么这个题一定是相乘不能是相加呢？y=k1A方-k2B （k1,k2大于0 ），也满足题目说的与A方成正比与B成反比啊？但是这道题只有相乘的情况才能选出正确答案
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1196浏览

[Undefined]

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Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.
 
Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?
答案C是怎么支持一个猜想又削弱另一个猜想的？
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2747浏览

[GWD]

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The author of the passage implies that which of the following is a possible partial explanation for acquisition behavior during the 1970's and 1980's?
请解释这道题为什么不选C或E，除了正确选项B，我认为文中也正确地提到了这两个选项可以解释acquisition behavior during 1970s and 80s
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[OG]

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The primary purpose of the passage is to
为什么选E不选B
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[Undefined]

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Club X has more than 10 but fewer than 40 members. Sometimes the members sit at tables with 3 members at one table and 4 members at each of the other tables, and sometimes they sit at tables with 3 members at one table and 5 members at each of the other tables. If they sit at tables with 6 members at each table except one and fewer than 6 members at that one table, how many members will be at the table that has fewer than 6 members?
提问小梅老师 这道题求讲一下 我没什么思路 带入数字得的是3
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1272浏览

[Undefined]

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A photography dealer ordered 60 Model X cameras to be sold for $250 each, which represents a 20 percent markup over the dealer's initial cost for each camera. Of the cameras ordered, 6 were never sold and were returned to the manufacturer for a refund of 50 percent of the dealer's initial cost. What was the dealer's approximate profit or loss as a percent of the dealer's initial cost for the 60 cameras?
请问小梅老师 这道题讲讲一下 我算的是19% 原来成本是200每个 亏了6个 每个亏100. 最后得不出答案
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302440浏览

[Undefined]

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Analytical!
请问may老师，这题该用什么思路来做？
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309567浏览

[Undefined]

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Analytical!
请问张老师，这道题为什么D不对？我有我觉得second paragraph最后一句话特别指向D
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