一些逻辑问题的分析

Eileenl

OG 59
59. In order to withstand tidal currents, juvenile horseshoe
crabs frequently burrow in the sand. Such burrowing
discourages barnacles from clinging to their shells.
When fully grown, however, the crabs can readily
withstand tidal currents without burrowing, and thus
they acquire substantial populations of barnacles.
Surprisingly, in areas where tidal currents are very
weak, juvenile horseshoe crabs are found not to have
signifi cant barnacle populations, even though they
seldom burrow.
Which of the following, if true, most helps to explain
the surprising fi nding?
(A) Tidal currents do not themselves dislodge
barnacles from the shells of horseshoe crabs.
(B) Barnacles most readily attach themselves to
horseshoe crabs in areas where tidal currents
are weakest.
(C) The strength of the tidal currents in a given
location varies widely over the course of a day.
(D) A very large barnacle population can signifi cantly
decrease the ability of a horseshoe crab to fi nd
food.
(E) Until they are fully grown, horseshoe crabs
shed their shells and grow new ones several
times a year.
实在觉得没有正确的答案，请教怎么选出答案E的？
OG 62
62. When there is less rainfall than normal, the water level
of Australian rivers falls and the rivers fl ow more
slowly. Because algae whose habitat is river water
grow best in slow-moving water, the amount of algae
per unit of water generally increases when there has
been little rain. By contrast, however, following a
period of extreme drought, algae levels are low even
in very slow-moving river water.
Which of the following, if true, does most to explain
the contrast described above?
(A) During periods of extreme drought, the
populations of some of the species that feed on
algae tend to fall.
(B) The more slowly water moves, the more
conducive its temperature is to the growth
of algae.
(C) When algae populations reach very high levels,
conditions within the river can become toxic for
some of the other species that normally live
there.
(D) Australian rivers dry up completely for short
intervals in periods of extreme drought.
(E) Except during periods of extreme drought, algae
levels tend to be higher in rivers in which the
fl ow has been controlled by damming than in
rivers that fl ow freel
我选的a,因为其它所需养分都死翘了，所以ALGAE张不好啊，答案D，请高人解答哈~
OG 69
69. Scientists have modifi ed feed corn genetically,
increasing its resistance to insect pests. Farmers who
tried out the genetically modifi ed corn last season
applied less insecticide to their corn fi elds 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 modifi ed seed would be unlikely to increase
profi ts.
Which of the following would it be most useful to know
in order to evaluate the argument?
(A) Whether there are insect pests that sometimes
reduce feed-corn yields, but against which
commonly used insecticides and the genetic
modifi cation 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 modifi ed corn last season applied
more insecticide than was actually necessary
(E) Whether, for most farmers who plant feed corn,
it is their most profi table crop
WHY D？

以上三题貌似很长，但都简单，希望大仙指点，谢谢~

ellenxiangyuan

Aroca City currently funds its public schools through taxes on property.              

In place of this system, the city plans to introduce a sales tax of three percent on all retail sales in the city.                                                            

Critics protest that three percent of current retail sales falls short of the amount raised for schools by property taxes.  The critics are correct on this point.  Nevertheless, implementing the plan will probably not reduce the money going to Aroca’s schools.  
   
Several large retailers have selected Aroca City as the site for huge new stores, and these are certain to draw large numbers of shoppers from neighboring municipalities,
 
where sales are taxed at rates of six percent and more.  In consequence, retail sales in Aroca City are bound to increase substantially.

In the argument given, the two potions in boldface play which of the following roles?

A.    The first presents a plan that the argument seeks to defend against a certain criticism; the second gives part of the basis for that criticism.
B.    The first presents a plan that the argument seeks to defend against a certain criticism; the second gives part of the basis for that defense.
C.    The first presents a plan that the argument criticizes; the second is a consideration raised by the argument in support of that critic
D.    The first presents a plan that the argument criticizes; the second presents a consideration that has been raised against that criticism.
E.    The first presents a plan whose consequences the argument seeks to evaluate; the second is presented by the argument as one likely consequence that is undesirable.
请问第二段被控出来的那句话 为什么是 undesirable, 谢谢帮解释一下~~~~

zoukan

先过来谢谢楼主！回复得很快，太热心了！

等做些GWD后再来看这里的题，现在看了怕自己模考就不准了。

aomeisoft7

OG 59
59. In order to withstand tidal currents, juvenile horseshoe
crabs frequently burrow in the sand. Such burrowing
discourages barnacles from clinging to their shells.
When fully grown, however, the crabs can readily
withstand tidal currents without burrowing, and thus
they acquire substantial populations of barnacles.
Surprisingly, in areas where tidal currents are very
weak, juvenile horseshoe crabs are found not to have
signifi cant barnacle populations, even though they
seldom burrow.
Which of the following, if true, most helps to explain
the surprising fi nding?
(A) Tidal currents do not themselves dislodge
barnacles from the shells of horseshoe crabs.
(B) Barnacles most readily attach themselves to
horseshoe crabs in areas where tidal currents
are weakest.
(C) The strength of the tidal currents in a given
location varies widely over the course of a day.
(D) A very large barnacle population can signifi cantly
decrease the ability of a horseshoe crab to fi nd
food.
(E) Until they are fully grown, horseshoe crabs
shed their shells and grow new ones several
times a year.
实在觉得没有正确的答案，请教怎么选出答案E的？
OG 62
62. When there is less rainfall than normal, the water level
of Australian rivers falls and the rivers fl ow more
slowly. Because algae whose habitat is river water
grow best in slow-moving water, the amount of algae
per unit of water generally increases when there has
been little rain. By contrast, however, following a
period of extreme drought, algae levels are low even
in very slow-moving river water.
Which of the following, if true, does most to explain
the contrast described above?
(A) During periods of extreme drought, the
populations of some of the species that feed on
algae tend to fall.
(B) The more slowly water moves, the more
conducive its temperature is to the growth
of algae.
(C) When algae populations reach very high levels,
conditions within the river can become toxic for
some of the other species that normally live
there.
(D) Australian rivers dry up completely for short
intervals in periods of extreme drought.
(E) Except during periods of extreme drought, algae
levels tend to be higher in rivers in which the
fl ow has been controlled by damming than in
rivers that fl ow freel
我选的a,因为其它所需养分都死翘了，所以ALGAE张不好啊，答案D，请高人解答哈~
OG 69
69. Scientists have modifi ed feed corn genetically,
increasing its resistance to insect pests. Farmers who
tried out the genetically modifi ed corn last season
applied less insecticide to their corn fi elds 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 modifi ed seed would be unlikely to increase
profi ts.
Which of the following would it be most useful to know
in order to evaluate the argument?
(A) Whether there are insect pests that sometimes
reduce feed-corn yields, but against which
commonly used insecticides and the genetic
modifi cation 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 modifi ed corn last season applied
more insecticide than was actually necessary
(E) Whether, for most farmers who plant feed corn,
it is their most profi table crop
WHY D？

以上三题貌似很长，但都简单，希望大仙指点，谢谢~

-- by 会员 Eileenl (2010/10/9 12:09:16)

59.
为抵抗潮汐，幼年螃蟹经常藏到沙洞里，可减少barnacle附着到螃蟹壳上。成年螃蟹不用躲藏就能抵御潮汐，因此他们壳上肯定会有很多barnacle。然而，在潮汐很少的地方，幼年螃蟹壳上很少躲在洞里，却只有很少barnacle。
求解释
(E) Until they are fully grown, horseshoe crabs shed their shells and grow new ones several times a year.
长大的时候，会经常换壳。（解释了为什么barnacle很少，因为换壳的时候掉了）


62.
降水量很少的适合，河里水量和流动速度都很慢。algae喜好在水流慢的水里，在降水量少的适合algae长的快。然而，在极度干旱时，algae在水流慢的水里生长却很缓慢
求解释
(A) During period of extreme drought,the populations of some of the species that feed on algae tend to fall.
干旱时，一些以algae为食的种类减少。（这和为什么algae生长缓慢有什么关系？而且some的样本没有代表性，什么都说明不了）
(D) Australian rivers dry up completely for short intervals in period of extreme drought.
极度干旱时，河流会干涸。（水都没了，algae还怎么长呢？解释了题干）


69.
转基因棉花增加了抗虫性。农民种转基因棉花需要的杀虫剂少，产量和普通棉花一样。然而普通棉花种子更便宜，种转基因棉花节省的杀虫剂的钱 没有弥补 买种子多花的钱。结论：不提倡种转基因棉花
求评价
(D) Whether most of the farmers who tried the genetically modifi ed corn last season applied more insecticide than was actually necessary
是否试图用转基因棉花的农民，使用的杀虫剂比正常需要的多。（这些农民用转基因棉花就会节省更多的杀虫剂，利润提高）



建议：这些都是OG的原题，书上的解释很清楚的，要仔细看看

aomeisoft7

Aroca City currently funds its public schools through taxes on property.              

In place of this system, the city plans to introduce a sales tax of three percent on all retail sales in the city.                                                            

Critics protest that three percent of current retail sales falls short of the amount raised for schools by property taxes.  The critics are correct on this point.  Nevertheless, implementing the plan will probably not reduce the money going to Aroca’s schools.  
   
Several large retailers have selected Aroca City as the site for huge new stores, and these are certain to draw large numbers of shoppers from neighboring municipalities,
 
where sales are taxed at rates of six percent and more.  In consequence, retail sales in Aroca City are bound to increase substantially.

In the argument given, the two potions in boldface play which of the following roles?

A.    The first presents a plan that the argument seeks to defend against a certain criticism; the second gives part of the basis for that criticism.
B.    The first presents a plan that the argument seeks to defend against a certain criticism; the second gives part of the basis for that defense.
C.    The first presents a plan that the argument criticizes; the second is a consideration raised by the argument in support of that critic
D.    The first presents a plan that the argument criticizes; the second presents a consideration that has been raised against that criticism.
E.    The first presents a plan whose consequences the argument seeks to evaluate; the second is presented by the argument as one likely consequence that is undesirable.
请问第二段被控出来的那句话 为什么是 undesirable, 谢谢帮解释一下~~~~

-- by 会员 ellenxiangyuan (2010/10/9 15:16:51)

Aroca City currently funds its public schools through taxes on property.  In place of this system, the city plans to introduce a sales tax of three percent on all retail sales in the city.  Critics protest that three percent of current retail sales falls short of the amount raised for schools by property taxes.  The critics are correct on this point.  Nevertheless, implementing the plan will probably not reduce the money going to Aroca’s schools.  Several large retailers have selected Aroca City as the site for huge new stores, and these are certain to draw large numbers of shoppers from neighboring municipalities, where sales are taxed at rates of six percent and more.  In consequence, retail sales in Aroca City are bound to increase substantially.


A城正通过财产税给公共学校筹资金。取代这个方法，A城计划对零售额征收3%的税。（先介绍背景，A城停收财产税，该收零售额税）批评者说对零售额征税来的钱比征财产税来的钱少。反对者说的是对的。（提出批评者反对收零售额税）然而，实施这个政策不会减少给学校的钱。（作者的观点：反对批评者，支持收零售额税）一些大的零售商已经选择在A成开新店，会吸引很多邻近消费者来购物，（作者阐明自己支持的原因）这些会收6%或更多的税。所以，销售额会显著增长。

A.    The first presents a plan that the argument seeks to defend against a certain criticism; the second gives part of the basis for that defense.
第一个黑体是作者支持的计划，反对批评者；第二个黑体是支持的原因。

claire921

请教楼主
OG12-15
A conservation group in the United States is trying to change the long-standing image of bats as frightening creatures. The group contends that bats are feared and persecuted solely because they are shy animals that are active only at night.

Which of the following, if true, would cast the most serious doubt on the accuracy of the group’s contention?

(A) Bats are steadily losing natural roosting places such as caves and hollow trees and are thus turning to more developed areas for roosting.
(B) Bats are the chief consumers of nocturnal insects and thus can help make their hunting territory more pleasant for humans.
(C) Bats are regarded as frightening creatures not only in the United States but also in Europe, Africa, and South America. Fear
(D) Raccoons and owls are shy and active only at night, yet they are not generally feared and persecuted.
(E) People know more about the behavior of other greatly feared animal species, such as lions, alligators, and snakes, than they do about the behavior of bats.
题目本身虽然做对了，但是对于OG中E的解释感到很迷茫~不太明白说的什么意思，能帮忙解释一下么？谢谢了~！
E  this suggests that more knowledge about the characteristics of some animal species may produce more, not less fear. But this is quite compatible with the idea that lack of knowledge about the behavior of bats could explain people’s fearful reaction to them. One e?ect of lack of knowledge, for example, is allowing false beliefs to ?ourish.

alicejingli

OG12—109
D错在哪里？回答假报警耽误真实报警，这个不就是说boxes必须拆掉吗？加强了，可为啥不对？

aomeisoft7

请教楼主
OG12-15
A conservation group in the United States is trying to change the long-standing image of bats as frightening creatures. The group contends that bats are feared and persecuted solely because they are shy animals that are active only at night.

Which of the following, if true, would cast the most serious doubt on the accuracy of the group’s contention?

(A) Bats are steadily losing natural roosting places such as caves and hollow trees and are thus turning to more developed areas for roosting.
(B) Bats are the chief consumers of nocturnal insects and thus can help make their hunting territory more pleasant for humans.
(C) Bats are regarded as frightening creatures not only in the United States but also in Europe, Africa, and South America. Fear
(D) Raccoons and owls are shy and active only at night, yet they are not generally feared and persecuted.
(E) People know more about the behavior of other greatly feared animal species, such as lions, alligators, and snakes, than they do about the behavior of bats.
题目本身虽然做对了，但是对于OG中E的解释感到很迷茫~不太明白说的什么意思，能帮忙解释一下么？谢谢了~！
E  this suggests that more knowledge about the characteristics of some animal species may produce more, not less fear. But this is quite compatible with the idea that lack of knowledge about the behavior of bats could explain people’s fearful reaction to them. One e?ect of lack of knowledge, for example, is allowing false beliefs to ?ourish.

-- by 会员 claire921 (2010/10/10 21:00:36)

一个美国保护组织试图改变人们长期以来认为蝙蝠很可怕的看法。他们指出蝙蝠让人害怕仅仅是因为蝙蝠害羞只在夜间活动。
求削弱


(E) People know more about the behavior of other greatly feared animal species, such as lions, alligators, and snakes, than they do about the behavior of bats.
人们对别的可怕动物的了解多于蝙蝠，比如狮子蛇（这个选项指出人们对蝙蝠不够了解。但是并没有说明 ”不够了解“ 是使人 更害怕蝙蝠 还是 不害怕蝙蝠 ，所以对结论没有任何作用）


E  this suggests that more knowledge about the characteristics of some animal species may produce more, not less fear. But this is quite compatible with the idea that lack of knowledge about the behavior of bats could explain people’s fearful reaction to them. One e?ect of lack of knowledge, for example, is allowing false beliefs to ?ourish.
这个选项假设是：对一个动物越了解，就越感到害怕。但是缺乏对蝙蝠的了解也可以解释人们的害怕。缺乏认识的一个影响就是是人产生错误的观念。

aomeisoft7

OG12—109
D错在哪里？回答假报警耽误真实报警，这个不就是说boxes必须拆掉吗？加强了，可为啥不对？

-- by 会员 alicejingli (2010/10/10 21:16:37)

Since virtually everyone has access to a private telephone, these alarm boxes have outlived their usefulness. Therefore, we propose to remove the boxes.
题干的逻辑是基于：因为有私人电话，所以才拆boxes。这样取消盒子才不会影响人们正常报警，也可以减少假报警。
D。假报警耽误真报警，只是指的假报警的危害， 有危害就代表一定要拆吗？题目那么强调私人电话的好处，所以必然要选A

alicejingli

38. Which of the following best completes the passage
below?
The computer industry’s estimate that it loses millions
of dollars when users illegally copy programs without
paying for them is greatly exaggerated. Most of the
illegal copying is done by people with no serious
interest in the programs. Thus, the loss to the industry
is quite small, because .
(A) many users who illegally copy programs never
find any use for them
(B) most people who illegally copy programs would
not purchase them even if purchasing them were
the only way to obtain them
(C) even if the computer industry received all the
revenue it claims to be losing, it would still be
experiencing financial difficulties
(D) the total market value of all illegal copies is low
in comparison to the total revenue of the
computer industry
(E) the number of programs that are frequently
copied illegally is low in comparison to the
number of programs available for sale
我知道这道填空属于A…therefore… B…..since,         类型。但是我的问题在于：我不明白B选项为啥对？
A代表了 那些弄盗版得人对软件利润不感兴趣
B  对于工厂来说损失小
那要用A-推-B的话，这个怎就变成B？
B的意思只是说盗版人们不会购买他们，哪怕购买是获得软件的唯一途径。
因为我想这个答案应该是关于盗版的人们不进行商业牟利方面的。但是结果选项都没有，我很郁闷。楼主有啥方法吗？对于这种填空题。


谢谢楼主