问答

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[Problem Solving]

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题目：

A shipment of 8 television sets contains 2 black-and-white sets and 6color sets. If 2 television sets are to be chosen at random from this shipment, what is the probability that at least 1 of the 2 sets chosen will be a black-and-white set?

选项:

A、1/7
B、1/4
C、5/14
D、11/28
E、13/28

答案:

E
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[Sentence Correction]

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题目：

Plants are more efficient at acquiring carbon than are fungi, in the form of carbon dioxide, and converting it to energy-rich sugars.

选项:

A、Plants are more efficient at acquiring carbon than are fungi,
B、Plants are more efficient at acquiring carbon than fungi,
C、Plants are more efficient than fungi at acquiring carbon,
D、Plants, more efficient than fungi at acquiring carbon,
E、Plants acquire carbon more efficiently than fungi,

答案:

C
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[Data Sufficiency]

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题目：

Guy's net income equals his gross income minus his deductions.  By what percent did Guy's net income change on January 1, 1989, when both his gross income and his deductions increased?
(1)       Guy's gross income increased by 4 percent on January 1, 1989.
(2)       Guy's deductions increased by 15 percent on January 1, 1989.

选项:

答案:

E
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[Problem Solving]

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题目：

If $2,000 in a savings account earned the equivalent of 8½ percent simple annual interest, how much interest did the amount earn in one year?

选项:

A、$160
B、$170
C、$180
D、$240
E、$260

答案:

B
1答疑

[Critical Reasoning]

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题目：

Certain genetically modified strains of maize produce a powerful natural insecticide. The insecticide occurs throughout the plant, including its pollen. Maize pollen is dispersed by the wind and frequently blows onto milkweed plants that grow near maize fields. Caterpillars of monarch butterflies feed exclusively on milkweed leaves. When these caterpillars are fed milkweed leaves dusted with pollen from modified maize plants, they die. Therefore, by using genetically modified maize, farmers put monarch butterflies at risk.

Which of the following would it be most useful to determine in order to evaluate the argument?

选项:

A、Whether the natural insecticide is as effective against maize-eating insects as commercial insecticides typically used on maize are
B、Whether the pollen of genetically modified maize contains as much insecticide as other parts of these plants
C、Whether monarch butterfly caterpillars are actively feeding during the part of the growing season when maize is releasing pollen
D、Whether insects that feed on genetically modified maize plants are likely to be killed by insecticide from the plant’s pollen
E、Whether any maize-eating insects compete with monarch caterpillars for the leaves of milkweed plants growing near maize fields

答案:

C
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[Sentence Correction]

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题目：

Many experts regarded the large increase in credit card borrowing in March not as a sign that households were pressed for cash and forced to borrow, rather a sign of confidence by households that they could safely handle new debt.

选项:

A、rather a sign of confidence by households that they could safely
B、yet as a sign of households’ confidence that it was safe for them to
C、but a sign of confidence by households that they could safely
D、but as a sign that households were confident they could safely
E、but also as a sign that households were confident in their ability safely to

答案:

D
1答疑

[Reading Comprehension]

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文章：

题目：

The last sentence in the passage serves primarily to

选项:

A、suggest that Krontiris’s work is not representative of recent trends among feminist scholars
B、undermine the argument that literate women of the Renaissance sought to oppose social constraints imposed on them
C、show a way in which Krontiris’s work illustrates a “cautiously optimistic” assessment of Renaissance women’s achievements
D、summarize Krontiris’s view of the effect of literacy on the lives of upper- and middle-class Renaissance women
E、illustrate the way in which Krontiris’s study differs from the studies done by Burckhardt and Kelly

答案:

C
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[Reading Comprehension]

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文章：

Line         Most attempts by physicists to send particles
  faster than the speed of light involve a remarkable
  phenomenon called quantum tunneling, in which
  particles travel through solid barriers that appear
(5) to be impenetrable. If you throw a ball at a wall,
  you expect it to bounce back, not to pass straight
  through it. Yet subatomic particles perform the
  equivalent feat. Quantum theory says that there is a
  distinct, albeit small, probability that such a particle
(10) will tunnel its way through a barrier; the probability
  declines exponentially as the thickness of the
  barrier increases. Though the extreme rapidity of
  quantum tunneling was noted as early as 1932,
  not until 1955 was it hypothesized—by Wigner and
(15) Eisenbud—that tunneling particles sometimes
#160; travel faster than light. Their grounds were
  calculations that suggested that the time it takes a
  particle to tunnel through a barrier increases with
  the thickness of the barrier until tunneling time
(20) reaches a maximum; beyond that maximum,
  tunneling time stays the same regardless of
  barrier thickness. This would imply that once
  maximum tunneling time is reached, tunneling
  speed will increase without limit as barrier thickness
(25) increases. Several recent experiments have
  supported this hypothesis that tunneling particles
  sometimes reach superluminal speed. According to
  measurements performed by Raymond Chiao and
  colleagues, for example, photons can pass through
(30) an optical filter at 1.7 times the speed of light.


题目：

Which of the following statements about the earliest scientific investigators of quantum tunneling can be inferred from the passage?

选项:

A、They found it difficult to increase barrier thickness continually.
B、They anticipated the later results of Chiao and his colleagues.
C、They did not suppose that tunneling particles could travel faster than light.
D、They were unable to observe instances of successful tunneling.
E、They made use of photons to study the phenomenon of tunneling.

答案:

C
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[Critical Reasoning]

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题目：

Healthy lungs produce a natural antibiotic that protects them from infection by routinely killing harmful bacteria on airway surfaces. People with cystic fibroses, however, are unable to fight off such bacteria, even though their lungs produce normal amounts of the antibiotic. Since the fluid on airway surfaces in the lungs of people with cystic fibrosis bas an abnormally high salt concentration, scientists hypothesize that in high salt environments the antibiotic becomes ineffective at killing harmful bacteria.
Which of the following, if it were obtained as an experimental result, would most decisively undermine the scientists' hypothesis?

选项:

A、Healthy lungs in which the salt concentration of the airway-surface fluid has been substantially increased are able to reestablish their normal salt concentration within a relatively short period of time.
B、The antibiotic produced by the lungs is effective at killing harmful bacteria even when salt concentrations are below levels typical of healthy lungs.
C、The salt concentration of the airway-surface fluid in the lungs of people who suffer from cystic fibrosis tends to return to its former high levels after having been reduced to levels typical of healthy lungs.
D、The lungs of people who suffer from cystic fibrosis are unable to fight off harmful bacteria even when the salt concentration is reduced to levels typical of healthy lungs.
E、The salt concentration in the airway-surface fluid of people whose lungs produce lower-than-average amounts of the antibiotic is generally much lower than that typical of healthy lungs.

答案:

D
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[Problem Solving]

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题目：

A technician makes a round-trip to and from a certain service center by the same route. If the technician completes the drive to the center and then completes 10 percent of the drive from the center, what percent of the round-trip has the technician completed?

选项:

A、5%
B、10%
C、25%
D、40%
E、55%

答案:

E
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1145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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3263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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3615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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1201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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2755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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1896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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1215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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1275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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302792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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309919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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