问答

2答疑

[Reading Comprehension]

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文章：

    More selective than most chemical pesticides in that they ordinarily destroy only unwanted species, biocontrol. agents (such as insects, fungi, and( viruses) eat, infect, or parasitize targeted plant or animal pests. However, biocontrol agents can negatively affect nontarget species by, for example, competing with them for resources: a biocontrol agent might reduce the benefits conferred by a desirable animal species by consuming a plant on which the animal prefers to lay its eggs. Another example of indirect negative. consequcnces occurred in England when a virus introduced to control rabbits reduced the amount of open ground (because large rabbit populations reduce the ground cover), in turn reducing underground ant nests and triggering the extinction of a blue butterfly that had depended on the nests to shelter its offspring. The paucity of known extinctions or disruptions resulting from indirect interactions may reflect not the infrequency of such mishaps but rather the failure to look for or to detect them: most organisms likely to be adversely affected by indirect interactions are of little or no known commercial value and the events linking a biocontrol agent with an adverse effect are often unclear. Moreover, determining the potential risks of biocontrol agents before they are used is difficult, especially when a nonnative agent is introduced, because, unlike a chemical pesticide, a biocontrol agent may adapt in unpredictable ways. so that it can feed on or otherwise harm new hosts.

题目：

The example presented by the author in the highlighted text most clearly serves to illustrate

选项:

A、a situation in which a species is less vulnerable to biocontrol agents than it would have been to chemical pesticides.
B、a way in which the introduction of a bio-control agent can affect a nontarget species.
C、a nonnative agent's adapting in an unpre-dictable way that results in damage to a new host.
D、The contention that biocontrol agents can harm nontarget species by competing with them for resources
E、the way in which indirect consequences from the use of biocontrol agents are most likely to occurs.

答案:

B
2答疑

[Critical Reasoning]

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题目：

To reduce the danger to life and property posed by major earthquakes, scientists have been investigating several techniques for giving advance warning of dangerous earthquakes.  Since catfish swim erratically before earthquakes, some investigators have proposed monitoring catfish to predict dangerous earthquakes.
 
Which of the following, if true, most seriously undermines the usefulness of the proposal?

选项:

A、In Japan, which is subject to frequent earthquakes, the behavior of catfish has long been associated with earthquakes.
B、Mechanical methods for detecting earthquakes have not proved effective.
C、Tremors lead to the release of hydrogen sulfide gas into water, thereby causing various fish and shellfish to behave erratically.
D、Careful construction can reduce the dangers posed by earthquakes.
E、Even very slight, fleeting tremors cause catfish to swim erratically.

答案:

E
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[Critical Reasoning]

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题目：

Last year a record number of new manufacturing jobs were created.  Will this year bring another record?  Well, any new manufacturing job is created either within an existing company or by the start-up of a new company.  Within existing firms, new jobs have been created this year at well below last year's record pace.  At the same time, there is considerable evidence that the number of new companies starting up this year will be no higher than it was last year and there is no reason to think that the new companies starting up this year will create more jobs per company than did last year's start-ups.  So clearly, the number of new jobs created this year will fall short of last year's record.
 
In the argument given, the two portions in boldface play which of the following roles?

选项:

A、The first provides evidence in support of the main conclusion of the argument; the second is a claim that argument challenges.
B、The first is a generalization that the argument seeks to establish; the second is a conclusion that the argument draws in order to support that generalization.
C、The first is a generalization that the argument seeks to establish; the second is a judgment that has been advanced in order to challenge that generalization.
D、The first is presented as obvious truth on which the argument is based; the second is a claim that has been advanced in support of a position that the argument opposes.
E、The first is presented as obvious truth on which the argument is based; the second is a judgment advanced in support of the main conclusion of the argument.

答案:

E
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[Critical Reasoning]

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题目：

Scientists have modified feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modified corn last season applied less insecticide to their corn fields and still got yields comparable to those they would have gotten with ordinary corn. Ordinary corn seed, however, costs less, and what these farmers saved on insecticide rarely exceeded their extra costs for seed. Therefore, for most feed-corn farmers, switching to genetically modified seed would be unlikely to increase profits.

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

选项:

A、Whether there are insect pests that sometimes reduce feed-corn yields, but against which commonly used insecticides and the genetic modification are equally ineffective
B、Whether the price that farmers receive for feed corn has remained steady over the past few years
C、Whether the insecticides typically used on feed corn tend to be more expensive than insecticides typically used on other crops
D、Whether most of the farmers who tried the genetically modified corn last season applied more insecticide than was actually necessary
E、Whether, for most farmers who plant feed corn, it is their most profitable crop

答案:

D
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[Sentence Correction]

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题目：

Most of the country’s biggest daily newspapers had lower circulation in the six months from October 1995 through March 1996 than a similar period a year earlier.

选项:

答案:

C
2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：

Information in the passage suggests that David Pearce would most readily endorse which of the following statements concerning monetization?

选项:

A、so stalking them over the treeless landscape, getting close enough to kill it
B、so to stalk them over the treeless landscape and get close enough to kill one
C、 so in order to stalk them over the treeless landscape and get close enough to kill one
D、and so in order to stalk it over the treeless landscape, getting close enough to kill it
E、and so stalking them over the treeless landscape and getting close enough in order to kill it

答案:

D
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[Sentence Correction]

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题目：

Unlike the other major planets, Pluto has a highly eccentric orbit, which is thus closer to the Sun than Neptune is for 20 years out of every 230-year cycle, even though it is commonly described as the remotest planet in the solar system.

选项:

A、 Pluto has a highly eccentric orbit, which is thus closer to the Sun than Neptune is
B、 Pluto has a highly eccentric orbit and is thus closer to the Sun than Neptune is
C、 Pluto's orbit is highly eccentric and is thus closer to the Sun than Neptune
D、 the orbit of Pluto is highly eccentric and thus closer to the Sun than Neptune
E、 the orbit of Pluto is highly eccentric, thus closer to the Sun than Neptune is

答案:

B
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[Sentence Correction]

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题目：

Once they had seen the report from the medical examiner, the investigators did not doubt whether the body recovered from the river was the man who had attempted to escape from the state prison.

选项:

A、did not doubt whether the body recovered from the river washave no doubt whether the body recovered from the river was
B、had not doubted that the body recovered from the river was
C、have no doubt whether the body recovered from the river was that of
D、had no doubt that the body recovered from the river was that of

答案:

E
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[Critical Reasoning]

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题目：

The Calex Telecommunications Company is planning to introduce cellular telephone service into isolated coastal areas of Caladia, a move which will require considerable investment.  However, the only significant economic activity in these areas is small-scale coffee farming, and none of the coffee farmers make enough money to afford the monthly service fees that Calex would have to charge to make a profit.  Nevertheless, Calex contends that making the service available to these farmers will be profitable.
Which of the following, if true, provides the strongest support for Calex's contention?

选项:

A、Currently, Caladian coffee farmers are forced to sell their coffee to local buyers at whatever price those buyers choose to pay because the farmers are unable to remain in contact with outside buyers who generally offer higher prices.
B、In the coastal areas of Caladia where Calex proposes to introduce cellular telephone service, there is currently no fixed-line telephone service because fixed-line companies do not believe that they could recoup their investment.
C、A cellular telephone company can break even with a considerably smaller number of subscribers than a fixed-line company can, even in areas such as the Caladian coast, where there is no difficult terrain to drive up the costs of installing fixed lines.
D、Calex bases its monthly fees for cellular telephone service in a given region partly on the cost of installing the necessary equipment to provide the service there.
E、Calex has for years made a profit on cellular telephone service in Caladia's capital city, which is not far from the coastal region.

答案:

A
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[Critical Reasoning]

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文章：

When species are extensively hunted, individuals that reach reproductive maturity early make up a larger proportion of the population, because they have a better chance of reproducing. When species face diminished food resources, on the other hand, individuals tend to take longer to reach reproductive maturity. These considerations may help settle whether the primary cause of the gradual disappearance of North America's mastodons, prehistoric animals related to elephants, was diminished food resources or human hunting, since __________.

题目：

Which of the following most logically completes the reasoning?

选项:

A、from the location of certain hunting weapons in juxtaposition with mastodon remains, it is possible to determine whether those weapons were used to hunt mastodonsthe average age at which mastodons reached reproductive maturity can be established from mastodon tusks, of which there are many fossils dating from different periods
B、from the remains of mastodons already discovered, it can be accurately estimated when mastodons became extinct 
C、from tusks and other bones, it is possible to determine whether male and female mastodons reached reproductive maturity at about the same age
D、it is possible to determine whether the earliest human dwellings constructed from mastodon tusks and bones come from an earlier period than the earliest hunting weapons unambiguously associated with mastodon remains

答案:

B
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1129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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3199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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3530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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1181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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2704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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1855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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[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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1253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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304074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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