问答

1答疑

[Data Sufficiency]

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题目：

Bowls X and Y each contained exactly 2 jelly beans, each of which was either red or black. One of the jelly beans in Bowl X was exchanged with one of the jelly beans in Bowl Y. After the exchange, were both of the jelly beans in Bowl X black?
  1. Before the exchange, Bowl X contained 2 black jelly beans.
  2. After the exchange, Bowl Y contained 1 jelly bean of each color.

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:

E
1答疑

[Data Sufficiency]

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题目：

If [x] denotes the least integer greater than or equal to x, is [x] = 0 ?

(1) -1 ＜ x＜ 1

(2) x ＜ 0

选项:

答案:

C
1答疑

[Sentence Correction]

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题目：

Nikola Tesla, the inventor of alternating current, because he was excited with the prospects of harnessing Niagara Falls for producing electric power, he predicted in the mid-1890's that electricity generated at Niagara would one day power the streetcars of London and the streetlights of Paris.

选项:

A、 Nikola Tesla, the inventor of alternating current, because he was excited with the prospects of harnessing Niagara Falls for producing electric power, he
B、 The prospects of harnessing Niagara Falls to produce electric power was exciting to Nikola Tesla, the inventor of alternating current, and so he
C、 Excited about the prospects of harnessing Niagara Falls to produce electric power, Nikola Tesla, the inventor of alternating current,
D、 Nikola Tesla, the inventor of alternating current, excited about the prospects of harnessing Niagara Falls for the production of electric power and
E、 The inventor of alternating current, excited with the prospects of harnessing Niagara Falls for producing of electric power, Nikola Tesla

答案:

C
1答疑

[Reading Comprehension]

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文章：

Line While the most abundant and dominant species
within a particular ecosystem is often crucial in
perpetuating the ecosystem, a “keystone” species,
here defined as one whose effects are much larger
(5) than would be predicted from its abundance, can
also play a vital role. But because complex species
interactions may be involved, identifying a keystone
species by removing the species and observing
changes in the ecosystem is problematic. It might
(10) seem that certain traits would clearly define a species
as a keystone species; for example,
Pisaster ochraceus is often a keystone predator
because it consumes and suppresses mussel
populations, which in the absence of this starfish
(15) can be a dominant species. But such predation on a
dominant or potentially dominant species occurs in
systems that do as well as in systems that do not
have species that play keystone roles. Moreover,
whereas P. ochraceus occupies an unambiguous
(20) keystone role on wave-exposed rocky headlands,
in more wave-sheltered habitats the impact of
P. ochraceus predation is weak or nonexistent,
and at certain sites sand burial is responsible for
eliminating mussels. Keystone status appears to
(25) depend on context, whether of particular
geography or of such factors as community
diversity (for example, a reduction in species
diversity may thrust more of the remaining species
into keystone roles) and length of species
(30) interaction (since newly arrived species in particular
may dramatically affect ecosystems).

题目：

The passage suggests which of the following about the identification of a species as a keystone species?

选项:

A、Such an identification depends primarily on the species’ relationship to the dominant species.
B、Such an identification can best be made by removing the species from a particular ecosystem and observing changes that occur in the ecosystem.
C、Such an identification is likely to be less reliable as an ecosystem becomes less diverse.
D、Such an identification seems to depend on various factors within the ecosystem.
E、Such an identification can best be made by observing predation behavior.

答案:

D
1答疑

[Critical Reasoning]

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题目：

Plant scientists have used genetic engineering on seeds to produce crop plants that are highly resistant to insect damage. Unfortunately, the seeds themselves are quite expensive, and the plants require more fertilizer and water to grow well than normal ones. Accordingly, for most farmers the savings on pesticides would not compensate for the higher seed costs and the cost of additional fertilizer. However, since consumer demand for grains, fruits, and vegetables grown without the use of pesticides continues to rise, the use of genetically engineered seeds of this kind is likely to become widespread.

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

选项:

A、The first supplies a context for the argument; the second is the argument's main conclusion.
B、The first introduces a development that the argument predicts will have a certain outcome; the second is a state of affairs that, according to the argument, contributes to bringing about that outcome.
C、The first presents a development that the argument predicts will have a certain outcome; the second acknowledges a consideration that tends to weigh against that prediction.
D、The first provides evidence to support a prediction that the argument seeks to defend; the second is that prediction.
E、The first and the second each provide evidence to support the argument's main conclusion.

答案:

C
1答疑

[Problem Solving]

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题目：

What is the largest integer n such that ?

选项:

A、5
B、6
C、7
D、10
E、51

答案:

B
1答疑

[Problem Solving]

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题目：

The sum of the first k positive integers is equal to . What is the sum of the integers from n to m, inclusive, where ?

选项:

A、 –
B、 –
C、 –
D、 –
E、 –

答案:

C
1答疑

[Critical Reasoning]

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题目：

Biologist: Species with broad geographic ranges probably tend to endure longer than species with narrow ranges. The broader a species’ range, the more likely that species is to survive the extinction of populations in a few areas. Therefore, it is likely that the proportion of species with broad ranges tends to gradually increase with time.

The biologist’s conclusion follows logically from the above if which of the following is assumed?

选项:

A、There are now more species with broad geographic ranges than with narrow geographic ranges.
B、Most species can survive extinctions of populations in a few areas as long as the species’ geographic range is not very narrow.
C、If a population of a species in a particular area dies out, that species generally does not repopulate that area.
D、If a characteristic tends to help species endure longer, then the proportion of species with that characteristic tends to gradually increase with time.
E、Any characteristic that makes a species tend to endure longer will make it easier for that species to survive the extinction of populations in a few areas.

答案:

D
1答疑

[Data Sufficiency]

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题目：

In the triangle above, is x > 90?
(1)     a2 + b2 < 15
(2)     c > 4

选项:

答案:

C
1答疑

[Reading Comprehension]

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文章：

Colonial historian David Allen's intensive study of five communities in seventeenth-century Massachusetts is a model of meticulous scholarship on the detailed microcosmic level, and is convincing up to a point.  Allen suggests that much more coherence and direct continuity existed between English and colonial agricultural practices and administrative organization than other historians have suggested.  However, he overstates his case with the declaration that he has proved "the remarkable extent to which diversity in New England local institutions was directly imitative of regional differences in the mother country."

 

Such an assertion ignores critical differences between seventeenth-century England and New England.  First, England was overcrowded and land-hungry; New England was sparsely populated and labor-hungry.  Second, England suffered the normal European rate of mortality; New England, especially in the first generation of English colonists, was virtually free from infectious diseases.  Third, England had an all-embracing state church; in New England membership in a church was restricted to the elect.  Fourth, a high proportion of English villagers lived under paternalistic resident squires; no such class existed in New England.  By narrowing his focus to village institutions and ignoring these critical differences, which studies by Greven, Demos, and Lockridge have shown to be so important, Allen has created a somewhat distorted picture of reality.

 

Allen's work is a rather extreme example of the "country community" school of seventeenth-century English history whose intemperate excesses in removing all national issues from the history of that period have been exposed by Professor Clive Holmes.  What conclusion can be drawn, for example, from Allen's discovery that Puritan clergy who had come to the colonies from East Anglia were one-third to one-half as likely to return to England by 1660 as were Puritan ministers from western and northern England?  We are not told in what way, if at all, this discovery illuminates historical understanding.  Studies of local history have enormously expanded our horizons, but it is a mistake for their authors to conclude that village institutions are all that mattered, simply because their functions are all that the records of village institutions reveal. 

题目：

The author of the passage is primarily concerned with

选项:

A、(A) substantiating a claim about a historical event
B、(B) reconciling two opposing ideas about a historical era
C、(C) disputing evidence a scholar uses to substantiate a claim about a historical event
D、(D) analyzing two approaches to scholarly research and evaluating their methodologies
E、(E) criticizing a particular study and the approach to historical scholarship it represents 

答案:

E
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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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3251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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3604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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1195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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1888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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1212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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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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302183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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309310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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