求助贴,老题目了,寻真正高手给真正答案

Rebeldom

Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants.  Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.  ossibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
A.    histidine is found in all parts of the plant—roots, stem, leaves, and flowers
B.    the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C.    others of the closely related group of plants are also found to produce histidine in large quantities
D.    cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E.    the concentration of histidine in the growing herb declines as the plant approaches maturity

flyincat

额，原来的答案选什么呀？我选D

Rebeldom

C和E的是比较主流的选择

flyincat

额，那就不知道了，等待牛人，这是什么的题啊，感觉好纠结

Rebeldom

自己顶自己,继续等

zhanghuijie

我也选D，因为D选项实际是对这句话……histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. 的一个加强。
也可以这么理解，histidine可以在试管实验中让金属的化学性质变惰性（这个单词原来不认识，刚查的），但是原文中并未说histidine可以在土壤中使金属的化学性质变惰性从而使植物可以生长（也许土壤中有别的物质使H不能发挥作用）。D选项正好说明了这一点，就是说是土壤中的H使金属的毒性减弱了。
实际上我觉得这个题的逻辑还是不够完整，只不过D对结论有正面作用。题目加上D选项总共说了这么几点条件：1.Herb能生长 2.Herb能产生histidine 3.在试管中histidine能是金属变惰性 4.Herb在土壤中能使金属毒性减弱。1是现象，造成这种现象我们可以认为可能有3个原因：1.group中的other plants中的物质使毒性减弱 2.Herb中的histidine使毒性减弱 3.Herb中的其他物质使毒性减弱。选项D第一、为我们排除了原因1，起到了排除他因他果的作用，是正确选项的特征。第二、D如果取非的话结论则绝对无法成立，也是正确选项的特征。

costan

Which of the following most logically completes the argument?
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants.  Agronomists studying the herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.  ossibly, therefore, the herb’s high histidine production is what allows it to grow in metal-rich soils, a hypothesis that would gain support if ______.
A.    histidine is found in all parts of the plant—roots, stem, leaves, and flowers
B.    the herb’s high level of histidine production is found to be associated with an unusually low level of production of other amino acids
C.    others of the closely related group of plants are also found to produce histidine in large quantities
D.    cultivation of the herb in soil with high concentrations of the metals will, over an extended period, make the soil suitable for plants to which the metals are toxic
E.    the concentration of histidine in the growing herb declines as the plant approaches maturity

-- by 会员 Rebeldom (2010/5/16 16:48:07)

我选C。

Rebeldom

选D不对,
结论是要证明the herb’s high histidine production is what allows it to grow in metal-rich soils
D选项是说,植物种在高金属含量土壤里可以逐渐使得土壤适合植物生长,没有提到植物本身的属性

Rebeldom

E其实也是无关的,成长的过程中histidine含量的降低
并不能说明histidine是植物可以生长在高金属土壤中的原因
C的确提高了整个ARGUMENT成立的概率,因为第一句的因素
A certain cultivated herb is one of a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants
通过第一句话可以看出C的确最好,提高了概率

gracezz

我也选了C~~