问答

2答疑

[Reading Comprehension]

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文章：

Most farmers attempting to control slugs and snails turn to baited slug poison, or molluscicide, which usually consists of a bran pellet containing either methiocarb or metaldehyde.  Both chemicals are neurotoxins that disrupt that part of the brain charged with making the mouth move in a coordinated fashion--the "central pattern generator"--as the slug feeds.  Thus, both neurotoxins, while somewhat effective, interfere with the slugs' feeding behavior and limit their ingestion of the poison, increasing the probability that some will stop feeding before receiving a lethal dose.  Moreover, slugs are not the only consumers of these poisons:  methiocarb may be toxic to a variety of species, including varieties of worms, carabid beetles, and fish.
 
Researchers are experimenting with an alternative compound based on aluminum, which may solve these problems, but this may well have a limited future as we learn more about the hazards of aluminum in the environment.  For example, some researchers suggest that acid rain kills trees by mobilizing aluminum in the soil, while others have noted that the human disease Alzheimer's is more prevalent in areas where levels of aluminum in the soil are high.  With farmers losing as much as 20 percent of their crops to slugs and snails even after treatment with currently available molluscicides, there is considerable incentive for researchers to come up with better and environmentally safer solutions.

题目：

In the passage, the author is primarily concerned with

选项:

A、describing the limitations of molluscicides that affect feeding behavior
B、proposing alternatives to current methods of controlling slugs and snails
C、emphasizing the need for an alternative to currently available molluscicides
D、explaining how molluscicides are used to control slugs and snails
E、criticizing the use of hazardous material for controlling slugs and snails

答案:

C
2答疑

[Sentence Correction]

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题目：

If current trends continue, by the year 2010 carbon emissions in the United States will soar to a level more than one-third higher than were those in 1990, according to official projections.

选项:

A、will soar to a level more than one-third higher than were those
B、will soar to a level more than one-third higher than that
C、would soar to a level more than one-third higher than it was
D、would soar to a level more than one-third higher than those
E、would soar to a level more than one-third higher than they were

答案:

B
2答疑

[Reading Comprehension]

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文章：

    Companies that must determine well in advance of the selling season how many unites of a new product to manufacture often underproduce products that sell well and have overstocks of others. The increased incidence in recent years of mismatches between production and demand seems ironic, since point-of-sale scanners have improved data on consumers' buying patterns and since flexible manufacturing has enabled companies to produce, cost-effectively, small quantities of goods. This type of manufacturing has greatly increased the number of new products introduced annually in the United States. However, frequent introductions of new products have two problematic side effects. For one, they reduce the average lifetime of products; more of them are neither at the beginning of their life (when prediction is difficult) or at the end of their life (when keeping inventory is expensive because the products will soon become obsolete). For another, as new products proliferate, demand is divided among a growing number of stock-keeping units (SKU's). Even though manufacturers and retailers can forecast aggregate demand with some certainty, forecasting accurately how that demand will be distributed among the many SKU's they sell is difficult. For example, a company may be able to estimate accurately the aggregate number of shoes it will sell, but it may be uncertain about which specific types of shoes will sell more than other types.

题目：

Which of the following most accurately describes the function of the last sentence in the passage (the highlighted text)?

选项:

A、To cite a situation in which the aggregate demand is more important than the distribution of demand among SKU's
B、To refute an assertion about the side effects of flexible manufacturing
C、To illustrate an assertion about companies' ability to forecast demand
D、To provide an example of ways in which companies address the difficulties of forecasting demand
E、To note an exception to the author's assertion about distributing demand among SKU's

答案:

C
2答疑

[Sentence Correction]

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题目：

Whereas heat transferred between the ocean and the atmosphere occurs more rapidly when the ocean is warmer than the air, it is slow when the ocean is colder.

选项:

A、Whereas heat transferred between the ocean and the atmosphere occurs more rapidly when the ocean is warmer than the air, it is slow when the ocean is colder.
B、Unlike the slow process of heat transfer between the ocean and the atmosphere when the ocean is colder than the air, heat transfers more rapidly when the ocean is warmer.
C、The transfer of heat between the ocean and the atmosphere is slow when the ocean is colder than the air and more rapid when the ocean is warmer.
D、Transferring heat between the ocean and the atmosphere occurs slowly when the ocean is colder than the air and more rapidly when it is warmer.
E、When the ocean is colder than the atmosphere, heat transferred between them occurs slowly, unlike the more rapid transfer occurring when the ocean is warmer.

答案:

C
2答疑

[Critical Reasoning]

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题目：

Beta Corporation claims that it no longer has enough work for the 60 computer data-entry workers that it is laying off.  These workers have heard, however, that the company is buying 100 new computers.  So the workers concluded that the company's real reason for laying them off is to fill their jobs with lower-paid workers.
Which of the following, if true, would most undermine the workers' conclusion?

选项:

A、Most of the workers being laid off know how to enter data on a number of different computer systems.
B、Orders for almost all of Beta Corporation products have increased over the past year.
C、A recent memorandum from the president of Beta Corporation requested that all data generated by the company be stored in computerized form.
D、Beta Corporation's computer data-entry workers are more experienced and hence more highly paid than people doing comparable work in other companies.
E、Beta Corporation's new computers will allow its current management and sales staff to perform many of the tasks that the data-entry workers were previously doing.

答案:

E
2答疑

[Critical Reasoning]

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题目：

Capuchin monkeys often rub their bodies with a certain type of millipede.  Laboratory tests show that secretions from the bodies of these millipedes are rich in two chemicals that are potent mosquito repellents, and mosquitoes carry parasites that debilitate capuchins.  Some scientists hypothesize that the monkeys rub their bodies with the millipedes because doing so helps protect them from mosquitoes.
 
Which of the following, if true, provides the most support for the scientists' hypothesis?

选项:

A、A single millipede often gets passed around among several capuchins, all of whom rub their bodies with it.
B、The two chemicals that repel mosquitoes also repel several other varieties of insects.
C、The capuchins rarely rub their bodies with the millipedes except during the rainy season, when mosquito populations are at their peak.
D、Although the capuchins eat several species of insects, they do not eat the type of millipede they use to rub their bodies.
E、The two insect-repelling chemicals in the secretions of the millipedes are carcinogenic for humans but do not appear to be carcinogenic for capuchins.

答案:

C
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[Problem Solving]

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题目：

2x + y = 12
│y│≤ 12
For how many ordered pairs (x, y) that 2 solutions of the system above are x and y both integers?

选项:

A、7
B、10
C、12
D、13
E、14

答案:

D
2答疑

[Data Sufficiency]

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题目：

If x is negative, is x ＜ -3?
(1)   x2 ＞ 9
(2) x3 ＜ -9
b

选项:

答案:

A
2答疑

[Problem Solving]

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题目：

The membership of a committee consists of 3 English teachers, 4 Mathematics teachers, and 2 Social Studies teachers.  If 2 committee members are to be selected at random to write the committee's report, what is the probability that the two members selected will both be English teachers?

选项:

A、   2/3
B、   1/3
C、   2/9
D、   1/12
E、   1/24

答案:

D
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[Problem Solving]

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题目：

What is the volume of a given cube?

(1) The ratio of an edge of the cube and the greatest distance between two points on the cube is

(2) The length of the diagonal across a face of the cube is 2.

选项:

A、Aif statement (1) ALONE is sufficient to answer the question but statement (2) alone is not sufficient;
B、Bif statement (2) ALONE is sufficient to answer the question but statement (1) alone is not sufficient;
C、Cif the two statements TAKEN TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient;
D、Dif EACH statement ALONE is sufficient to answer the question;
E、Eif the two statements TAKEN TOGETHER are still NOT sufficient to answer the question.     

答案:

B
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418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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1443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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1613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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619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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1426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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1009浏览

[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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672浏览

[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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690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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160238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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167347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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