OG2017一道CR题，看不懂请nn帮忙解答

springwitch

这题看不懂，请大牛讲解一下，非常感谢！

In the country of Marut, the Foreign Trade agency's records were reviewed in 1994 in light of informtion then newly available about neighbouring Goro. The review revealed that in every year since 1963, the agency's projection of what Goro's grossnational product (GNP) would be five years later was a serious underestimate. The review also revealed that in every year since 1963, the agency estimated Goro's GNP for the previous year---a Goro state secret---very accurately.

Of the following claims, which is most strongly supported by the statements given ?

A) Goro's GNP fluctuated greatly between 1963 and 1994.
B) Prior to 1995, Goro had not released data intended to mislead the agency in making its five-year projections.
C) The amount by which the agency underestimated the GNP it projected for Goro tended to increase over time.
D) Even before the new information came to light, the agency had reason to think that at least some of the five-year projections it had made were inaccurate.
E) The agency's five year projections of Goro's GNP had no impact on economic planning in Marut.

答案是D

Ahrennister

答案是D？
这题我感觉是这个review讲了两件事：
1. 从1963年开始，每年会对后五年的GNP进行预估，即1963会预估1968的，但这个预估不准，数据被严重低估了；
2. 从1963年开始，每年对前一年的GNP的预估都很精确，即1963预估1962的GNP，1964预估1963的GNP，以此类推。
如果这样的话，在1969年，agency会对1968年的GNP进行精准的预估，因为1968是1969的前一年；然而这时候他们就会发现在1963年对1968年GNP的预估是有问题的，因为1968是1963的后五年，根据题目，这预估会被低估。因此agency不需要获得其他的数据就可以判定五年预估的GNP是不精确的。
所以选D。
希望对LZ有帮助。

Ahrennister

Ahrennister 发表于 2016-11-12 23:45
答案是D？
这题我感觉是这个review讲了两件事：
1. 从1963年开始，每年会对后五年的GNP进行预测，即1963会 ...

哦原来答案被涂白了啊。。。。做的时候我还真没发现- -

拼图跑步旅游

贴一个helr的解释  
http://gmat.la/question/OG2017-CR-661

springwitch

Ahrennister 发表于 2016-11-12 23:48
哦原来答案被涂白了啊。。。。做的时候我还真没发现- -

非常感谢！解释的很清楚。答案留白是为了不干扰思维。

springwitch

拼图跑步旅游 发表于 2016-11-12 23:57
贴一个helr的解释  
http://gmat.la/question/OG2017-CR-661

非常感谢mm的链接！

猪小王

Ahrennister 发表于 2016-11-12 23:45
答案是D？
这题我感觉是这个review讲了两件事：
1. 从1963年开始，每年会对后五年的GNP进行预估，即1963会 ...

从1969年到1993年，每年有两个estimated GNPs：five-year later estimated GNP_1 和 retrospective estimated GNP_2，结果是GNP_1<GNP_2。由于每年都存在预测的误差，那么至少我们可以怀疑某一些年份的five-year later estimation是错误的。
D选项用词很谨慎，“at least some of ..." 说明不排除GNP for the previous year也会出错。