3 道ＯＧ，看看嘛！og-96,og-131,og-153

freegirl

96.The difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. The train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. Thus a sufficient market for the train will not exist.

Which of the following, if true, most severely weakens the argument presented above?
(A) Cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically.
(B) Cars and buses are not nearly as fast as the high-speed train will be.
(C) Planes are not a free-wheel system because they can fly only between airports, which are less convenient for consumers than the high-speed train’s stations would be.
(D) The high-speed train line cannot use currently underutilized train stations in large cities.
(E) For long trips, most people prefer to fly rather than to take ground-level transportation.

Answer is C.
不是说削弱只能削弱论证过程，不能单纯否定论据么？ Answer C 说 Planes are not a free-wheel system 不正好与原文的论据相悖么？　
---------------------------------------------------------------------------------------------------------------
Bank depositors in the United States are all financially protected against bank failure because the government insures all individuals' bank deposits. An economist argues that this insurance is partly responsible for the high rate of bank failures, since it removes from depositors any financial incentive to find out whether the bank that holds their money is secure against failure.
If depositors were more selective, then banks would need to be secure in order to compete for depositors' money.
131. Which of the following, if true, most seriously weakens the economist's argument?
(A) Before the government started to insure depositors against bank failure, there was a lower rate of bank failure than there is now.
(B) When the government did not insure deposits, frequent bank failures occurred as a result of depositors' fears of losing money in bank failures.
(C) Surveys show that a significant proportion of depositors are aware that their deposits are insured by the government.
(D) There is an upper limit on the amount of an individual's deposit that the government will insure, but very few individuals' deposits exceed thislimit.
(E) The security of a bank against failure depends on the percentage of its assets that are loaned out and also on how much risk its loans involve.

Answer is B. E 为什么说是无关呢？ 为什么不可看成是他因削弱？
-----------------------------------------------------------------------------------------------------------
153. Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade. However, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
Which of the following, if true, does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?
(A) The cost of oil has fallen dramatically.
(B) The reduction in the cost of solar-power equipment has occurred despite increased raw material costs for that equipment.
(C) Technological changes have increased the efficiency of oil-fired power plants.
(D) Most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants.
(E) When the price of oil increases, reserves of oil not previously worth exploiting become economically viable.

Answer is C. 但不明白：However, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
NN, 帮我解释一下好吗？

因为大考在即，若有重复提问的地方，还请各位不厌其烦再指一条明路！

freegirl

怎么没有人理我？ 55555555

cognito

for 1 don't rely too much on what u learned in New oriental
try to understand the question by yourself

dorbear

96.the difficulty with the proposed high-speed train line is that a used plane can be bought for one-third the price of the train line, and the plane, which is just as fast, can fly anywhere. the train would be a fixed linear system, and we live in a world that is spreading out in all directions and in which consumers choose the free-wheel systems (cars, buses, aircraft), which do not have fixed routes. thus a sufficient market for the train will not exist.

which of the following, if true, most severely weakens the argument presented above?
(a) cars, buses, and planes require the efforts of drivers and pilots to guide them, whereas the train will be guided mechanically.
(b) cars and buses are not nearly as fast as the high-speed train will be.
(c) planes are not a free-wheel system because they can fly only between airports, which are less convenient for consumers than the high-speed train’s stations would be.
(d) the high-speed train line cannot use currently underutilized train stations in large cities.
(e) for long trips, most people prefer to fly rather than to take ground-level transportation.

answer is c.
不是说削弱只能削弱论证过程，不能单纯否定论据么？ answer c 说 planes are not a free-wheel system 不正好与原文的论据相悖么？　
===============================
这种情况只是适用于假设题，即当你必须用去反来判断是否原名题不成立的时候才对。

dorbear

bank depositors in the united states are all financially protected against bank failure because the government insures all individuals' bank deposits. an economist argues that this insurance is partly responsible for the high rate of bank failures, since it removes from depositors any financial incentive to find out whether the bank that holds their money is secure against failure.
if depositors were more selective, then banks would need to be secure in order to compete for depositors' money.
131. which of the following, if true, most seriously weakens the economist's argument?
(a) before the government started to insure depositors against bank failure, there was a lower rate of bank failure than there is now.
(b) when the government did not insure deposits, frequent bank failures occurred as a result of depositors' fears of losing money in bank failures.
(c) surveys show that a significant proportion of depositors are aware that their deposits are insured by the government.
(d) there is an upper limit on the amount of an individual's deposit that the government will insure, but very few individuals' deposits exceed thislimit.
(e) the security of a bank against failure depends on the percentage of its assets that are loaned out and also on how much risk its loans involve.

answer is b. e 为什么说是无关呢？ 为什么不可看成是他因削弱？
==========================================
Depends on 后面是一个必要条件的表达，不构成对Bank Failure的充分条件，即不是它因。
My admission to Yale depends on how high I can score on Gmat, considering the fierce competition among the applicants around the globe.

dorbear

153. technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade. however, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
which of the following, if true, does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?
(a) the cost of oil has fallen dramatically.
(b) the reduction in the cost of solar-power equipment has occurred despite increased raw material costs for that equipment.
(c) technological changes have increased the efficiency of oil-fired power plants.
(d) most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants.
(e) when the price of oil increases, reserves of oil not previously worth exploiting become economically viable.

answer is c. 但不明白：however, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
nn, 帮我解释一下好吗？
-----------------------------------------------------------------------
直译的话有点不会说，但我理解是：要使太阳能实用化，必须在价格上与油价相当。虽然太阳能的成本降低，可是还是一直比油价高出一定的水平。因为油价也一直在降。

不知理解是否正确。

xin_bj

参考一下吧：
http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=22057&id=3901&star=1&skin=0
http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=55113&id=8384&star=1&skin=0
http://forum.chasedream.com/dispbbs.asp?BoardID=24&replyID=67300&id=10005&star=1&skin=0

freegirl

仰天长叹，斑竹的脑袋怎么没长在我的肩膀上！吃鱼太少应该是一个不聪明脑袋的必要条件吧。。。

dorbear

非常感谢 xin_bj 提供的线索，非常有帮助。也预祝 freegirl 考试成功！

tangnaibin

这道题目简直是一个高难数学题。

我觉得ETS的陷阱在于，题目中给出的条件太多，混淆了大家的视线，也浪费了很多不必要的脑细胞。我的理解是这样的，请大家指正：

第一句话technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.基本上是废话，换算成公式来理解：分子都是总成本，分母是产生的能量值，这样solar energy far more cost-efficient；但是于本题不相干。

括号里面的解释，我通过google勾过，还是不明白the threshold of economic viability 的具体数学表达公式。所以我就武断地理解the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants为：每桶油用于new solar power plants发电的价格成本的提升和同样一桶油用于new oil-fired power plants发电的价格成本的提升相差35刀。这样的理解只能是the efficiency of oil-fired power plants提高了。而a选项中的油的单价显然起不到作用了。

请各位NN指教