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标题: 求助，gwd-11-21 [打印本页]

作者: knifekelly 时间: 2004-9-21 22:02
标题: 求助，gwd-11-21

Q21:

Healthy lungs produce a natural antibiotic that protects them from infection by routinely killing harmful bacteria on airway surfaces. eople with cystic fibrosis, however, are unable to fight off such bacteria, even though their lungs produce normal amounts of the antibiotic. The fluid on airway surfaces in the lungs of people with cystic fibrosis has an abnormally high salt concentration; accordingly, scientists hypothesize that the high salt concentration is what makes the antibiotic ineffective.

Which of the following, if true, most strongly supports the scientists’ hypothesis?

A. When the salt concentration of the fluid on the airway surfaces of healthy people is raised artificially, the salt concentration soon returns to normal.

B. A sample of the antibiotic was capable of killing bacteria in an environment with an unusually low concentration of salt.

C. When lung tissue from people with cystic fibrosis is maintained in a solution with a normal salt concentration, the tissue can resist bacteria.

D. Many lung infections can be treated by applying synthetic antibiotics to the airway surfaces.

E. High salt concentrations have an antibiotic effect in many circumstances.

是实在不明白，有两个答案，一个选Ａ，一个选Ｄ

作者: kingsoft 时间: 2004-9-21 23:30

选C

原文说高盐浓度导致抗体失效

选项说正常盐浓度抗体有用

支持

作者: knifekelly 时间: 2004-9-21 23:36
我当归纳题做了，呵呵，头晕了！

作者: card_mistress 时间: 2004-9-23 08:35

D is incorrect because it basically means that antibiotics are not susceptible to salt, i.e., the synthetic antibiotics, when applied to a surface containing salt, remain effective. This does not strengthen the argument.

Is it A or C??? I can't decide which? Anyone help?!!!!!!!!

作者: yanying76 时间: 2004-9-25 05:59

以下是引用kingsoft在2004-9-21 23:30:00的发言：

选C

原文说高盐浓度导致抗体失效

选项说正常盐浓度抗体有用

支持

但是泡在溶液里的人体组织不能说明问题，不是大活人一个

我觉得a更好

作者: micht 时间: 2004-9-25 07:25

A. When the salt concentration of the fluid on the airway surfaces of healthy people is raised artificially, the salt concentration soon returns to normal.

(A) indicates that after antibiotoic interacts with the highly salt concentration of fluid on the airyway, salt concentration returns to normal.

所以 effective antibotic 可以 cause salt concentraton return to normal! ==> 所以salt concentration不會導致ineffective antiboitc...無法strengthen hypothesis.. A不選

I'll choose C instead...is C correct?

作者: starfishz 时间: 2004-9-25 19:10

這題....是OG的吧??? 我贊成C

作者: sarah81 时间: 2004-11-11 19:53
Agree C.

作者: calla 时间: 2005-5-17 21:02
这题我也是选C, 但是我想问，B为什么不对？

作者: supernova_zou 时间: 2005-6-1 15:08

我认为b错在

1,b选项说A sample of the antibiotic 并不一定就是指的文中的antibiotic.

2,况且这个 antibiotic 在 high salt concentration 中也可以是有效的.

作者: aloha 时间: 2005-7-16 09:31

以下是引用supernova_zou在2005-6-1 15:08:00的发言：

我认为b错在

1,b选项说A sample of the antibiotic 并不一定就是指的文中的antibiotic.

2,况且这个 antibiotic 在 high salt concentration 中也可以是有效的.

But in the question, it tells that " the high salt concentration is what makes the antibiotic ineffective."

Why B is not right?

作者: zk1980 时间: 2005-9-24 10:42

以下是引用supernova_zou在2005-6-1 15:08:00的发言：

我认为b错在

1,b选项说A sample of the antibiotic 并不一定就是指的文中的antibiotic.

2,况且这个 antibiotic 在 high salt concentration 中也可以是有效的.

我觉得你说的这第二个理由同样可以用在反驳C上， lung tissue 同样可以在hing salt concentrate中有效。请指正！

作者: zhoujian 时间: 2005-12-26 12:37

选C

作者: weimingosi 时间: 2006-3-17 10:06

题目：HIGH SLAT CONCENTRATION与病情同时出现，怀疑是否SALT为因

C：当没有HIGH SALT CONCENTRATIONG是，没病情出现。证明SALT为因

这是非常常规的科学实验方法啊。一般是生物实验都是要这么有对比组去证实假设是否成立的

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