ＯＧ ８７， 这题不明白？

maggiecookies

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

(E) All laboratory tests to detect pironoma have the same proportion of false negative results.

The best choose is E,

yaoyao99

Tests have 2 problems:  A, false positive and B, false negative.
The conclusion is to improve the tests, they should choose a test that minimize A.
The best support is the one that states B does not matter, because all tests have the same problem with B at the same level.

maggiecookies

对不起, 我还是有点不清楚, 但好象想想是这样的

    A.. B 两部份....如果,B相同, 那末对A 的支持就有SUPPORT 的作用.

  谢谢!

yaoyao99

Yes.  Because B is a constant factor, in order to increase
the reliability of the test, the only thing you can do is to improve
upon problem A.

[此贴子已经被作者于2006-5-1 23:59:15编辑过]

Raymond_GMAT

我不理解的是为什么强调all,请教.

(E) All laboratory tests to detect pironoma have the same proportion of false negative results.

rainbowbravo

总的False=positive + negative

想要比较positive与总的False的事儿，就以定要让negative这一项确定不变，那么all，不正是确定了所有的negative都不变吗？