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1答疑

[Critical Reasoning]

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题目：

The ancient Nubians inhabited an area in which typhus occurs, yet surprisingly few of their skeletons show the usual evidence of this disease.  The skeletons do show deposits of tetracycline, an antibiotic produced by a bacterium common in Nubian soil.  This bacterium can flourish on the dried grain used for making two staples of the Nubian diet, beer and bread.  Thus, tetracycline in their food probably explains the low incidence of typhus among ancient Nubians.
 
Which of the following is an assumption on which the argument relies?

选项:

A、Infectious diseases other than typhus to which the ancient Nubians were exposed are unaffected by tetracycline.
B、Tetracycline is not rendered ineffective as an antibiotic by exposure to the processes involved in making bread and beer.
C、Typhus cannot be transmitted by ingesting bread or beer contaminated with the infectious agents of this disease.
D、Bread and beer were the only items in the diet of the ancient Nubians which could have contained tetracycline.
E、Typhus is generally fatal.

答案:

B
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[Critical Reasoning]

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题目：

In parts of South America, vitamin-A deficiency is a serious health problem, especially among children. In one region, agriculturists are attempting to improve nutrition by encouraging farmers to plant a new variety of sweet potato called SPK004 that is rich in beta-carotene, which the body converts into vitamin A. The plan has good chances of success, since sweet potato is a staple of the region's diet and agriculture, and the varieties currently grown contain little beta-carotene.

Which of the following, if true, most strongly supports the prediction that the plan will succeed?

选项:

A、
A. The growing conditions required by the varieties of sweet potato currently cultivated in the region are conditions in which SPK004 can flourish.
B、
B. The flesh of SPK004 differs from that of the currently cultivated sweet potatoes in color and texture, so traditional foods would look somewhat different when prepared from SPK004.
C、
C. There are no other varieties of sweet potato that are significantly richer in beta-carotene than SPK004 is.
D、
D. The varieties of sweet potato currently cultivated in the region contain some important nutrients that are lacking in SPK004.
E、
E. There are other vegetables currently grown in the region that contain more beta-carotene than the currently cultivated varieties of sweet potato do.

答案:

A
1答疑

[Reading Comprehension]

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文章：

Line The argument for “monetizing”—or putting a
monetary value on—ecosystem functions may be
stated thus: Concern about the depletion of natural
resources is widespread, but this concern, in the
(5) absence of an economic argument for conservation,
has not translated into significant conservational
progress. Some critics blame this impasse on
environmentalists, whom they believe fail to address
the economic issues of environmental degradation.
(10) Conservation can appear unprofitable when compared
with the economic returns derived from converting
natural assets (pristine coastlines, for example) into
explicitly commercial ones (such as resort hotels).
But according to David Pearce, that illusion stems
(15) from the fact that “services” provided by ecological
systems are not traded on the commodities market,
and thus have no readily quantifiable value. To
remedy this, says Pearce, one has to show that all
ecosystems have economic value—indeed, that all
(20) ecological services are economic services. Tourists
visiting wildlife preserves, for example, create
jobs and generate income for national economies;
undisturbed forests and wetlands regulate water
runoff and act as water-purifying systems, saving
(25) millions of dollars worth of damage to property
and to marine ecosystems. In Gretchen Daily’s
view, monetization, while unpopular with many
environmentalists, reflects the dominant role that
economic considerations play in human behavior,
(30) and the expression of economic value in a common
currency helps inform environmental decision-making
processes.

题目：

According to the passage, Daily sees monetization as an indication of which of the following?

选项:

A、The centrality of economic interests to people’s actions
B、The reluctance of the critics of environmentalism to acknowledge the importance of conservation
C、The inability of financial interests and ecological interests to reach a common ideological ground
D、The inevitability of environmental degradation
E、The inevitability of the growth of ecological services in the future

答案:

A
1答疑

[Reading Comprehension]

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文章：

Line When asteroids collide, some collisions cause
an asteroid to spin faster; others slow it down. If
asteroids are all monoliths—single rocks—undergoing
random collisions, a graph of their rotation rates
(5) should show a bell-shaped distribution with statistical
“tails” of very fast and very slow rotators. If asteroids
are rubble piles, however, the tail representing the
very fast rotators would be missing, because any
loose aggregate spinning faster than once every few
(10) hours (depending on the asteroid’s bulk density)
would fly apart. Researchers have discovered that
all but five observed asteroids obey a strict limit on
rate of rotation. The exceptions are all smaller than
200 meters in diameter, with an abrupt cutoff for
(15) asteroids larger than that.
The evident conclusion—that asteroids larger than
200 meters across are multicomponent structures or
rubble piles—agrees with recent computer modeling
of collisions, which also finds a transition at that
(20) diameter. A collision can blast a large asteroid to bits,
but after the collision those bits will usually move
slower than their mutual escape velocity. Over several
hours, gravity will reassemble all but the fastest
pieces into a rubble pile. Because collisions among
(25) asteroids are relatively frequent, most large bodies
have already suffered this fate. Conversely, most
small asteroids should be monolithic, because impact
fragments easily escape their feeble gravity.

题目：

According to the passage, which of the following is a prediction that is based on the strength of the gravitational attraction of small asteroids?

选项:

A、Small asteroids will be few in number.
B、Small asteroids will be monoliths.
C、Small asteroids will collide with other asteroids very rarely.
D、Most small asteroids will have very fast rotation rates.
E、Almost no small asteroids will have very slow rotation rates.

答案:

B
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[Problem Solving]

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题目：

The diagram shows a table, in which the four columns represents week days, i.e., Monday, Tuesday, Wednesday, and Thursday and the rows represents the name of the company, i.e., company A, company B, company C, company D, company E.

The table shows the numbers of packages shipped daily by each of five companies during a 4-day period. The standard deviation of the numbers of packages shipped daily during the period was greatest for which of the five companies?

选项:

A、A
B、B
C、C
D、D
E、E

答案:

B
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[Problem Solving]

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题目：

If w, x, y, and z are integers such that 1﹤w﹤x﹤y﹤z and wxyz = 462, then z =?瑡椠⁳

选项:

A、7
B、11
C、14
D、21
E、42

答案:

B
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[Sentence Correction]

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题目：

The relative prosperity of the first years of the twentieth century came to a halt in 1907 when drains on the money supply, revealing a weak national financial infrastructure of banking and credit, it precipitated an economic crisis that lasted nearly a year.

选项:

A、supply, revealing a weak national financial infrastructure of banking and credit, it precipitated
B、Supply, revealing a weak national financial infrastructure of banking and credit, they precipitated
C、Supply both revealed a weak national financial infrastructure of banking and credit and precipitating
D、Supply revealed both a weak national financial infrastructure of banking and credit and precipitating
E、Supply revealed a weak national infrastructure of banking and credit and precipitated

答案:

E
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[Reading Comprehension]

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文章：

Line         There are recent reports of apparently drastic
  declines in amphibian populations and of extinctions
  of a number of the world’s endangered amphibian
  species. These declines, if real, may be signs of a
(5) general trend toward extinction, and many
  environmentalists have claimed that immediate
  environmental action is necessary to remedy
  this “amphibian crisis,” which, in their view, is an
  indicator of general and catastrophic environmental
(10) degradation due to human activity.
       To evaluate these claims, it is useful to make a
  preliminary distinction that is far too often ignored.
  A declining population should not be confused with
  an endangered one. An endangered population is
(15) always rare, almost always small, and, by definition,
  under constant threat of extinction even without a
  proximate cause in human activities. Its disappearance,
  however unfortunate, should come as no great
  surprise. Moreover, chance events—which may
(20) indicate nothing about the direction of trends in
  population size—may lead to its extinction. The
  probability of extinction due to such random factors
  depends on the population size and is independent of
  the prevailing direction of change in that size.
(25)      For biologists, population declines are potentially
  more worrisome than extinctions. Persistent
  declines, especially in large populations, indicate a
  changed ecological context. Even here, distinctions
  must again be made among declines that are only
(30) apparent (in the sense that they are part of habitual
  cycles or of normal fluctuations), declines that take
  a population to some lower but still acceptable
  level, and those that threaten extinction (e.g., by
  taking the number of individuals below the minimum
(35) viable population). Anecdotal reports of population
  decreases cannot distinguish among these
  possibilities, and some amphibian populations have
  shown strong fluctuations in the past.
       It is indisputably true that there is simply not
(40) enough long-term scientific data on amphibian
  populations to enable researchers to identify real
  declines in amphibian populations. Many fairly
  common amphibian species declared all but extinct
  after severe declines in the 1950s and 1960s
(45) have subsequently recovered, and so might
  the apparently declining populations that have
  generated the current appearance of an amphibian
  crisis. Unfortunately, long-term data will not soon
  be forthcoming, and postponing environmental
(50) action while we wait for it may doom species and
  whole ecosystems to extinction.


题目：

The primary purpose of the passage is to

选项:

A、assess the validity of a certain view
B、distinguish between two phenomena
C、identify the causes of a problem
D、describe a disturbing trend
E、allay concern about a particular phenomenon

答案:

A
1答疑

[Critical Reasoning]

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文章：

One variety of partially biodegradable plastic beverage container is manufactured from small bits of plastic bound together by a degradable bonding agent such as cornstarch. Since only the bonding agent degrades, leaving the small bits of plastic, no less plastic refuse per container is produced when such containers are discarded than when comparable nonbiodegradable containers are discarded.

题目：

Which of the following, if true, most strengthens the argument above?

选项:

A、Both partially biodegradable and nonbiodegradable plastic beverage containers can be crushed completely flat by refuse compactors.The partially biodegradable plastic beverage containers are made with more plastic than comparable nonbiodegradable ones in order to compensate for the weakening effect of the bonding agents.
B、Many consumers are ecology-minded and prefer to buy a product sold in the partially biodegradable plastic beverage containers rather than in nonbiodegradable containers, even if the price is higher. 
C、The manufacturing process for the partially biodegradable plastic beverage containers results in less plastic waste than the manufacturing process for nonbiodegradable plastic beverage containers.
D、Technological problems with recycling currently prevent the reuse as food or beverage containers of the plastic from either type of plastic beverage container. 

答案:

B
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[Critical Reasoning]

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文章：

Hotco oil burners, designed to be used in asphalt plants, are so efficient that Hotco will sell one to the Clifton Asphalt plant for no payment other than the cost savings between the total amount the asphalt plant actually paid for oil using its former burner during the last two years and the total amount it will pay for oil using the Hotco burner during the next two years. On installation, the plant will make an estimated payment, which will be adjusted after two years to equal the actual cost savings.

题目：

Which of the following, if it occurred, would constitute a disadvantage for Hotco of the plan described above?

选项:

A、Another manufacturer's introduction to the market of a similarly efficient burner The Clifton Asphalt plant's need for more than one new burner 
B、Very poor efficiency in the Clifton Asphalt plant's old burner 
C、A decrease in the demand for asphalt
D、A steady increase in the price of oil beginning soon after the new burner is installed  

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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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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[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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[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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