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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：

The author of the passage mentions “escape velocity” (see line 22) in order to help explain which of the following?

选项:

A、The tendency for asteroids to become smaller rather than larger over time
B、The speed with which impact fragments reassemble when they do not escape an asteroid’s gravitational attraction after a collision
C、The frequency with which collisions among asteroids occur
D、The rotation rates of asteroids smaller than 200 meters in diameter
E、The tendency for large asteroids to persist after collisions

答案:

E
1答疑

[Reading Comprehension]

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文章：

Line         In Winters v. United States (1908), the Supreme
  Court held that the right to use waters flowing through
  or adjacent to the Fort Belknap Indian Reservation
  was reserved to American Indians by the treaty
(5) establishing the reservation. Although this treaty did
  not mention water rights, the Court ruled that the
  federal government, when it created the reservation,
  intended to deal fairly with American Indians by
  reserving for them the waters without which their
(10) lands would have been useless. Later decisions, citing
  Winters, established that courts can find federal rights
  to reserve water for particular purposes if (1) the
  land in question lies within an enclave under exclusive
  federal jurisdiction, (2) the land has been formally
(15) withdrawn from federal public lands—i.e., withdrawn
  from the stock of federal lands available for private
  use under federal land use laws—and set aside
  or reserved, and (3) the circumstances reveal the
  government intended to reserve water as well as land
(20) when establishing the reservation.
       Some American Indian tribes have also established
  water rights through the courts based on their
  traditional diversion and use of certain waters prior
  to the United States’ acquisition of sovereignty. For
(25) example, the Rio Grande pueblos already existed
  when the United States acquired sovereignty over
  New Mexico in 1848. Although they at that time
  became part of the United States, the pueblo lands
  never formally constituted a part of federal public
(30) lands; in any event, no treaty, statute, or executive
  order has ever designated or withdrawn the pueblos
  from public lands as American Indian reservations.
  This fact, however, has not barred application of the
  Winters doctrine. What constitutes an American Indian
(35) reservation is a question of practice, not of legal
  definition, and the pueblos have always been treated
  as reservations by the United States. This pragmatic
  approach is buttressed by Arizona v. California (1963),
  wherein the Supreme Court indicated that the manner
(40) in which any type of federal reservation is created
  does not affect the application to it of the Winters
  doctrine. Therefore, the reserved water rights of
  Pueblo Indians have priority over other citizens’ water
  rights as of 1848, the year in which pueblos must be
(45) considered to have become reservations.


题目：

The passage suggests that the legal rights of citizens other than American Indians to the use of water flowing into the Rio Grande pueblos are

选项:

A、guaranteed by the precedent set in Arizona v. California
B、abolished by the Winters doctrine
C、deferred to the Pueblo Indians whenever treaties explicitly require this
D、guaranteed by federal land-use laws
E、limited by the prior claims of the Pueblo Indians

答案:

E
1答疑

[Reading Comprehension]

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文章：

Line Anthropologists once thought that the ancestors
of modern humans began to walk upright because
it freed their hands to use stone tools, which they
had begun to make as the species evolved a brain of
(5) increased size and mental capacity. But discoveries
of the three-million-year-old fossilized remains of
our hominid ancestor Australopithecus have yielded
substantial anatomical evidence that upright walking
appeared prior to the dramatic enlargement of the
(10) brain and the development of stone tools.
Walking on two legs in an upright posture (bipedal
locomotion) is a less efficient proposition than walking
on all fours (quadrupedal locomotion) because several
muscle groups that the quadruped uses for propulsion
(15) must instead be adapted to provide the biped with
stability and control. The shape and configuration
of various bones must likewise be modified to allow
the muscles to perform these functions in upright
walking. Reconstruction of the pelvis (hipbones) and
(20) femur (thighbone) of “Lucy,” a three-million-year-old
skeleton that is the most complete fossilized skeleton
from the Australopithecine era, has shown that they
are much more like the corresponding bones of the
modern human than like those of the most closely
(25) related living primate, the quadrupedal chimpanzee.
Lucy’s wide, shallow pelvis is actually better suited to
bipedal walking than is the rounder, bowl-like pelvis of
the modern human, which evolved to form the larger
birth canal needed to accommodate the head of a
(30) large-brained human infant. By contrast, the head of
Lucy’s baby could have been no larger than that of a
baby chimpanzee.
If the small-brained australopithecines were not
toolmakers, what evolutionary advantage did they
(35) gain by walking upright? One theory is that bipedality
evolved in conjunction with the nuclear family:
monogamous parents cooperating to care for their
offspring. Walking upright permitted the father to
use his hands to gather food and carry it to his mate
(40) from a distance, allowing the mother to devote more
time and energy to nurturing and protecting their
children. According to this view, the transition to
bipedal walking may have occurred as long as ten
million years ago, at the time of the earliest hominids,
(45) making it a crucial initiating event in human evolution.

题目：

The primary purpose of the passage is to

选项:

A、present an interpretation of the chronological relationship between bipedal locomotion and certain other key aspects of human evolution
B、compare the evolutionary advantages and disadvantages of bipedal locomotion to those of quadrupedal locomotion
C、argue that the transition to a nuclear family structure was a more crucial step in human evolution than was the development of stone tools
D、analyze anatomical evidence of bipedal locomotion to show that the large brain of modern humans developed at a later stage of evolution than was previously believed
E、use examples of muscle and bone structure to illustrate the evolutionary differences between modern humans, australopithecines, and chimpanzees

答案:

A
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[Sentence Correction]

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题目：

Sophisticated laser-guided land graders can now flatten uneven farmland almost perfectly so as not to waste rainwater in runoff down sloping fields.

选项:

A、so as not to waste rainwater
B、so that rainwater is not wasted
C、so that there is no wasted rainwater
D、and thereby not waste rainwater
E、and there is no rainwater wasted

答案:

B
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[Sentence Correction]

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题目：

Rejecting its argument that the Masters Dog Training Club’s primary aim was to teach people to train dogs, the court ruled the club ineligible for tax exemption as an educational group.

选项:

A、Rejecting its argument that the Masters Dog Training Club’s primary aim was to teach people to train dogs, the court ruled the club ineligible for tax exemption as an educational group.
B、In rejecting the Masters Dog Training Club’s argument that their primary aim was to teach people to train dogs, the court ruled the club ineligible to be exempted of taxes as an educational group.
C、Rejecting the argument that the primary aim of the Masters Dog Training Club was to teach people to train dogs, the court ruled that the club was ineligible for exemption from taxes as an educational group.
D、The club was not to be exempted of taxes as an educational group, ruled the court by rejecting its argument that the primary aim of the Masters Dog Training Club was teaching people to train dogs.
E、The court ruled the Masters Dog Training Club not eligible to be exempted from taxes as an educational group, rejecting the argument that the primary aim was to teach people to train dogs.

答案:

C
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[Critical Reasoning]

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题目：

Half of the subjects in an experiment--the experimental group--consumed large quantities of a popular artificial sweetener.  Afterward, this group showed lower cognitive abilities than did the other half of the subjects--the control group--who did not consume the sweetener.  The detrimental effects were attributed to an amino acid that is one of the sweetener's principal constituents.
Which of the following, if true, would best help explain how the sweetener might produce the observed effect?

选项:

A、The government's analysis of the artificial sweetener determined that it was sold in relatively pure form.
B、A high level of the amino acid in the blood inhibits the synthesis of a substance required for normal brain functioning.
C、Because the sweetener is used primarily as a food additive, adverse reactions to it are rarely noticed by consumers.
D、The amino acid that is a constituent of the sweetener is also sold separately as a dietary supplement.
E、Subjects in the experiment did not know whether they were consuming the sweetener or a second, harmless substance.

答案:

B
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[Reading Comprehension]

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题目：

Which of the following best describes the organization of the passage?

选项:

A、A problem is acknowledged, the causes are explored, and a solution is offered.
B、A question is raised, opposing points of view are evaluated, and several alternative answers are discussed.
C、A means of dealing with a problem is proposed, and the manner in which a solution was reached is explained.
D、A plan of action is advanced, and the probable outcomes of that plan are discussed.
E、Two competing theories are described and then reconciled.

答案:

A
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[Critical Reasoning]

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题目：

Columnist: Metro City has a lower percentage of residents with humanities degrees than any other city of comparable size in our nation. Nationwide, university graduates generally earn more than people who are not university graduates, but those with humanities degrees typically earn less than do graduates with degrees in other disciplines. So the main reason Metro City has higher income per capita than any other city of comparable size in our nation must be its low percentage of residents with humanities degrees.

Which of the following, if true, would most strengthen the columnist's argument?

选项:

A、Metro City residents with humanities degrees have higher income per capita than do people with humanities degrees in any other city of comparable size in the nation.
B、The percentage of residents with university degrees is lower in Metro City than in any other city of comparable size in the nation.
C、Nationwide, university graduates without humanities degrees typically earn more than do individuals without university degrees.
D、Metro City residents with degrees outside the humanities have per capita income no higher than the per capita income of such residents of other cities of comparable size in the nation.
E、In Metro City, a lower proportion of university graduates have humanities degrees than in any other city of comparable size in the nation.

答案:

D
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[Data Sufficiency]

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题目：

A department manager distributed a number of pens, pencils,
and pads among the staff in the department, with each staff
member receiving x pens, y pencils, and z pads. How many
staff members were in the department?
(1)    The numbers of pens, pencils, and pads
that each staff member received were in
the retio 2:3:4, respectively.
(2)    The manager distributed a total of
18 pens, 27 pencils, and 36 pads.

选项:

答案:

E
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[Problem Solving]

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题目：

A set of numbers has the property that for any number t in the set, t + 2 is in the set. If -1 is in the set, which of the following must also be in the set?

I.-3

II.1

III.5

选项:

A、I only
B、II only
C、I and II only
D、II and III only
E、I, II, and III

答案:

D
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[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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[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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1500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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[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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[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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641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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[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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