[求助]急问一到JJ

howardwang

以下是引用xinfaxian在2005-8-19 13:22:00的发言：

题干中的arge amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert .不就是你所说的必要条件吗？还是我没有理解MM的意思？

leonchan

以下是引用howardwang在2005-8-19 13:03:00的发言：

结论是the herb’s high histidine production is what allows it to grow in metal-rich soils

因为herb是能在对其他植物有毒害作用中的类似植物中的一种（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. ）

而herb经研究，会产生large amounts of histidine，histidine对metal有化学方面的抑制作用。

而C认为，对其他植物有毒害作用中的类似植物中也含有大量的histidine

也就是说，同类产生相同结果的事物有某个共同的特征，那么，很有可能是这个共同特征导致了这个相同的结果。（虽然不必然，但是，支持不需要必然）

同意howardwang对C的分析  又是一个比较“弱”的支持

D肯定错误 D说这种herb能使土壤改良以至于make the soil suitable for plants to which the metals are toxic  这种说法和结论“the herb’s high histidine production is what allows it to grow in metal-rich soils” 完全无关 无法在high histidine production与grow in metal-rich soils之间建立联系

A与E一样 对结论不能产生支持作用

xinfaxian

隔了几天，现在想想应该是C.

D 重复了题干的信息，ETS 阴险题,又上了一会当！

潜龙勿用

C is the best answer.

For D,it is just consistent with the premise.

joeysue

以下是引用kathleen在2005-7-21 22:14:00的发言：

  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 . Possibly, 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

请各位帮忙看一下此题应该选什么 ?  多谢

选c，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.注意这里的thrive 用的是复数，表明这些植物都能在这种环境里生存，所以如果这些植物也发现生产这种物质的话，无疑是支撑。

Colin33

支持C, 原因同oeysue. 不是因为C有多强, 而是其他选项太差, GMAT就是一个相对选择的游戏.

勇敢的小熙牛

我认为应该选D,因为题目问的很清楚: 是不是histidine导致herb能够在metal-rich soils里面grow.
然后我们来看，在metal-rich soils这个环境下其他种类的植物很难生存。言下之意是metal rich导致的。那么，最argubly的证据是在不存在metal rich 的情况下，其他植物能否生存。与此同时，题目给出资料说是herd产生的histidine导致metals chemically inert,什么意思？意思就是在这种状态下其他植物是可以生存的啊！所以，虽然其他争议大的选项有辩解的理由，但是相比之下这个是最直接命中要害的。故选D.