[求助]急问一到JJ

kathleen

  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

Lucky0506

B.

bigmouse

I choose D

kathleen

我选的也是D, 可是我手头的答案是选E, 能有人帮忙确认一下吗？

jeffchai

I choose C.

Reasoning: this plant can survive and it can produce H  =====hypothesis=====> because it can produce H, it survive. If other plants produce H can also survive, it will support this hypothesis.

Lucky0506

我今天改选D.

请NN确认！

[此贴子已经被作者于2005-8-19 11:36:03编辑过]

howardwang

应该是C

xinfaxian

偶选D.

C 看上去有关，应该是无关选项吧。因为C 说其他closely related group of plants也可产生大量的 histidine，但这并不能说明histidine,即一种氨基酸使土壤中的金属成分不活跃。

而D 说，这种herb在本来有金属毒的土壤植了相当长一段时间后，可以使其他本来因金属毒不能生长的植物生长。说明这种herb里的histidine对金属活跃性有抑制作用。因此logically completes the argument.

howardwang

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）

[此贴子已经被作者于2005-8-19 13:05:10编辑过]

xinfaxian

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

（对！但是这里是不能缺少这个histidine里的氨基酸抑制了金属成分的必要条件的。没有的话，是不能完成上面这个结论的 ：the herb’s high histidine production is what allows it to grow in metal-rich soils。再说，如果这个条件完全没有用的话，题干里说明了一长串，那不是没必要吗？）请继续指教！

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）

[此贴子已经被作者于2005-8-19 13:22:21编辑过]