问答

2答疑

[Reading Comprehension]

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文章：

In terrestrial environments, gravity places special demands on the cardiovascular systems of animals.  Gravitational pressure can cause blood to pool in the lower regions of the body, making it difficult to circulate blood to critical organs such as the brain.  Terrestrial snakes, in particular, exhibit adaptations that aid in circulating blood against the force of gravity.
 
The problem confronting terrestrial snakes is best illustrated by what happens to sea snakes when removed from their supportive medium.  Because the vertical pressure gradients within the blood vessels are counteracted by similar pressure gradients in the surrounding water, the distribution of blood throughout the body of sea snakes remains about the same regardless of their orientation in space, provided they remain in the ocean. When removed from the water and tilted at various angles with the head up, however, blood pressure at their midpoint drops significantly, and at brain level falls to zero.  That many terrestrial snakes in similar spatial orientations do not experience this kind of circulatory failure suggests that certain adaptations enable them to regulate blood pressure more effectively in those orientations.
 
One such adaptation is the closer proximity of the terrestrial snake's heart to its head, which helps to ensure circulation to the brain, regardless of the snake's orientation in space.  The heart of sea snakes can be located near the middle of the body, a position that minimizes the work entailed in circulating blood to both extremities.  In arboreal snakes, however, which dwell in trees and often assume a vertical posture, the average distance from the heart to the head can be as little as 15 percent of overall body length.  Such a location requires that blood circulated to the tail of the snake travel a greater distance back to the heart, a problem solved by another adaptation.  When climbing, arboreal snakes often pause momentarily to wiggle their bodies, causing waves of muscle contraction that advance from the lower torso to head.  By compressing the veins and forcing blood forward, these contractions apparently improve the flow of venous blood returning to the heart.

题目：

The passage provides information in support of which of the following assertions?

选项:

A、The disadvantages of an adaptation to a particular feature of an environment often outweigh the advantages of such an adaptation.
B、An organism's reaction to being placed in an environment to which it is not well adapted can sometimes illustrate the problems that have been solved by the adaptations of organisms indigenous to that environment.
C、The effectiveness of an organism's adaptation to a particular feature of its environment can only be evaluated by examining the effectiveness with which organisms of other species have adapted to a similar feature of a different environment.
D、Organisms of the same species that inhabit strikingly different environments will often adapt in remarkably similar ways to the few features of those environments that are common.
E、Different species of organisms living in the same environment will seldom adapt to features of that environment in the same way.

答案:

B
2答疑

[Data Sufficiency]

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题目：

In the xy-plane, line l and line k intersect at the point (16/5, 12/5).  What is the slope of line l?
(1)     The product of the slopes of line l and line k is –1.
(2)     Line k passes through the origin.

选项:

答案:

C
2答疑

[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
  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：

The author of the passage mentions calculations about tunneling time and barrier thickness in order to

选项:

A、suggest that tunneling time is unrelated to barrier thickness
B、explain the evidence by which Wigner and Eisenbud discovered the phenomenon of tunneling
C、describe data recently challenged by Raymond Chiao and colleagues
D、question why particles engaged in quantum tunneling rarely achieve extremely high speeds
E、explain the basis for Wigner and Eisenbud’s hypothesis

答案:

E
2答疑

[Critical Reasoning]

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文章：

In order to reduce the number of items damaged while in transit to customers, packaging consultants recommended that the TrueSave mail-order company increase the amount of packing material so as to fi ll any empty spaces in its cartons. Accordingly, TrueSave offi cials instructed the company’s packers to use more packing material than before, and the packers zealously acted on these instructions and used as much as they could. Nevertheless, customer reports of damaged items rose somewhat.

题目：

Which of the following, if true, most helps to explain why acting on the consultants’ recommendation failed to achieve its goal?

选项:

A、The change in packing policy led to an increase in expenditure on packing material and labor.When packing material is compressed too densely, it loses some of its capacity to absorb shock.
B、The amount of packing material used in a carton does not signifi cantly infl uence the ease with which a customer can unpack the package
C、Most of the goods that TrueSave ships are electronic products that are highly vulnerable to being damaged in transit.
D、TrueSave has lost some of its regular customers as a result of the high number of damaged items they received. 

答案:

B
2答疑

[Sentence Correction]

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题目：

Yellow jackets number among the 900 or so species of the world's social wasps, wasps living in a highly cooperative and organized society where they consist almost entirely of females—the queen and her sterile female workers.

选项:

A、wasps living in a highly cooperative and organized society where they consist almost entirely of
B、wasps that live in a highly cooperative and organized society consisting almost entirely of
C、which means they live in a highly cooperative and organized society, almost all
D、which means that their society is highly cooperative, organized, and it is almost entirely
E、living in a society that is highly cooperative, organized, and it consists of almost all

答案:

B
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[Sentence Correction]

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题目：

Antarctica receives more solar radiation than does any other place on Earth, yet the temperatures are so cold and the ice cap is reflective, so that little polar ice melts during the summer; otherwise, the water levels of the oceans would rise 250 feet and engulf most of the world's great cities.

选项:

A、is reflective, so that little polar ice melts during the summer; otherwise,
B、is so reflective that little of the polar ice melts during the summer; were it to do so,
C、so reflective that little polar ice melts during the summer, or else
D、reflective, so that little of the polar ice melts during the summer, or
E、reflects so that little of the polar ice melts during the summer; if it did

答案:

B
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[Sentence Correction]

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题目：

Salt deposits and moisture threaten to destroy the Mohenjo-Daro excavation in Pakistan, the site of an ancient civilization that flourished at the same time as the civilizations in the Nile Delta and the river valleys of the Tigris and Euphrates.

选项:

A、that flourished at the same time as the civilizations
B、that had flourished at the same time as had the civilizations
C、that flourished at the same time those had
D、flourishing at the same time as those did
E、flourishing at the same time as those were

答案:

A
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[Problem Solving]

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题目：

If x percent of 40 is y, then 10x equals

选项:

A、4y
B、10y
C、25y
D、100y
E、400y

答案:

C
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[Problem Solving]

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题目：

How many different 6-letter sequences are there that consist of 1 A , 2 B 's, and 3 C 's ?

选项:

A、6
B、60
C、120
D、360
E、720

答案:

B
2答疑

[Critical Reasoning]

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题目：

According to a review of 61 studies of patients suffering from severely debilitating depression, a large majority of the patients reported that missing a night's sleep immediately lifted their depression.  Yet sleep-deprivation is not used to treat depression even though the conventional treatments, which use drugs and electric shocks, often have serious side effects.
 
Which of the following, if true, best explains the fact that sleep-deprivation is not used as a treatment for depression?

选项:

A、For a small percentage of depressed patients, missing a night's sleep induces a temporary sense of euphoria.
B、Keeping depressed patients awake is more difficult than keeping awake people who are not depressed.
C、Prolonged loss of sleep can lead to temporary impairment of judgment comparable to that induced by consuming several ounces of alcohol.
D、The dramatic shifts in mood connected with sleep and wakefulness have not been traced to particular changes in brain chemistry.
E、Depression returns in full force as soon as the patient sleeps for even a few minutes.

答案:

E
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791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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2411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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2639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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923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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2117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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1459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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948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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983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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230346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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237470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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