求助： OG10 -- Q30,Q87,Q172

pennybecky

30. The price the government pays for standard weapons purchased from military contractors is determined by a pricing method called “historical costing.” Historical costing allows contractors to protect their profits by adding a percentage increase, based on the current rate of inflation, to the previous year’s contractual price.

Which of the following statements, if true, is the best basis for a criticism of historical costing as an economically sound pricing method for military contracts?
A. The government might continue to pay for past inefficient use of funds.
B. The rate of inflation has varied considerably over the past twenty years.
C. The contractual price will be greatly affected by the cost of materials used for the products.
D. Many taxpayers question the amount of money the government spends on military contracts.
E. The pricing method based on historical costing might not encourage the development of innovative weapons.

87. In tests for pironoma, a serious disease, a false positive result indicates that people have pironoma when, in fact, they do not; a false negative result indicates that people do not have pironoma when, in fact, they do. To detect pironoma most accurately, physicians should use the laboratory test that has the lowest proportion of false positive results.

Which of the following, if true, gives the most support to the recommendation above?
(A) The accepted treatment for pironoma does not have damaging side effects.
(B) The laboratory test that has the lowest proportion of false positive results causes the same minor side effects as do the other laboratory tests used to detect pironoma.
(C) In treating pironoma patients, it is essential to begin treatment as early as possible, since even a week of delay can result in loss of life.
(D) The proportion of inconclusive test results is equal for all laboratory tests used to detect pironoma.
(E) All laboratory tests to detect pironoma have the same proportion of false negative results.

172. There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand between different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies.

To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following?
(A) A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary.
(B) The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered.
(C) There are several categories of surgical procedure (other than hysterectomies, prostatectomies, and tonsillectomies) that are often performed unnecessarily.
(D) For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded.
(E) With respect to how often they are performed unnecessarily, hysterectomies,  prostatectomies, and tonsillectomies are representative of surgical procedures in general.
30 题的答案是A .
87 题的答案是E.
172 题的答案是B .
虽然资料里有解释，但是还是看不懂。求各位帮忙解释一下，谢谢

kevin0214

建议：搜索论坛以前的帖子，一般至少都有翻译和大体思路，有些选项的细节也讨论过。如果没有你需要的内容，请把具体什么地方不理解说清楚，最好说明自己怎么想的。这样你可以得到更快的帮助，如果你的问题可以一句话解释清楚，就会有很多人愿意回答。把三道题题目重新翻译一遍，然后写思路分析选项这种事，很少人愿意做。
另外，把题目分开发帖问比较好。

yfan2

都很模棱两可

joananna

看完论坛里的解释想通了。
http://forum.chasedream.com/GMAT_CR/thread-46431-1-1.html