[求助]补充：39

雪落无声 · 发表于 2004-3-2 12:41:00

Blood banks will shortly start to screen all donors for NANBhepatitis.Although the new screening tests are estimated to diaqualify up to 5 percent of all prospective blood donors,they will still miss 2/3 of donors carrying NANA hepatitis.Therefore ,about 10percent of actual donors will still supply NANA-contaminated blood.

39.the argument above denpends on which of the following assumption?

a,donors carrying NANB hepatitis do not ,in a large percentage of cases ,carry other infections for which reliable screening tests are routinely performed

b,donors carrying NANB hepatitis do not ,in a large percentage of cases,develop the diasease themselves at any point

c,the estimate of the number of donors who would be disqualified by tests for NANB hepatitis is an underestimate

D,the incidence of NANB hepatitis is lower among the potential blood donors than it is in the population at large

e.the donors who will still supply NANB contaminated blood will donate blood at the average frequency for all donors

选A，CONFUSED

HELP！谢谢

番茄炒蛋 · 发表于 2004-3-2 12:54:00

这里说的是其他的病不会被检测出来

如果还有其他的病，而现有的检测手段有能够查出来，那这些根本就不会出现在鲜血名单里面

这样才会有原文的结论Therefore ,about 10percent of actual donors will still supply NANA-contaminated blood

雪落无声 · 发表于 2004-3-2 13:15:00

那么那些数字5%，2/3，10%怎么得出来？

逻辑结构这样吧

因为：排除5%有其他病的Donor,漏2/3有N病毒的人

ASSUMPTION，带有N病毒的在第一轮SCREEN中不会被排除，也就是说不带有其他病毒

所以；实际donor中仍有被N感染的

weiyu · 发表于 2004-3-2 14:42:00

Disqualify在M-W中的解释

1 : to deprive of the required qualities, properties, or conditions : make unfit
2 : to deprive of a power, right, or privilege
3 : to make ineligible for a prize or for further competition because of violations of the rules
我觉得是：错误排除了5%没毛病的donor, 在有N病的人种又漏掉了2/3有毛病的donor->10%的donor是有N病的，但参加了blood donation.

谁能解释一下5%, 2/3, 10%之间的联系呢? I am confused.

[求助]补充：39

[求助]补充：39

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