新鲜出炉的真题又一道 - 脑水开搅！ (Herb/Toxic matel)

dingrhan

Tricky 的真题又一道： 争论集中于D/E。 我一开始选D，但再一想，E 在假设和结论间建立了某种联系，似乎更好。大家意下如何？

28. 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

jerrold0023

比选项DE。

文中说acid可以是metal变得inert，表明了acid对环境的作用。

E说acid的浓度与植物生长时期的关系，无关。

jerrold0023

被迫选D

dingrhan

有某种HERB，可繁茂生存于含有毒金属的土壤中。经查，该HERB产生一种Histidine，使金属的化学属性成惰性。

推论：是这种Histidine 确保此HERB生存于此金属多多之土壤。

E： 为了加强推论，就设法在Histidine和 假设的它对土壤中金属的影响建立逻辑关系： 当植物成熟了，Herb里Histidine 的含量也少了，即，被消耗在解毒中了。

我并不确定选E，只是觉得E也有它的道理。

roberta

我觉得选D,排除他因。

open to discussion:-)

Xandria

楼主对E的理解不对, 选项在说长成以后下降了, 没说长成时和长成以前比下降了!

E是无关选项.

sensornet

E说的是concentration of histidine的变化，而题目说的是histidine的存在对植物生存的影响。如果你对E的解释成立，这个也只能算是indirect的选项。OG里面CR的解释有关于indirect的讨论。

这道题我也觉得是被迫选D。我对生物比较无知，但我来个大胆的推测。假设D对，我可以出道weaken 选项D结论的题，就是render的过程只在植物内部进行，histidine没有被排放到周边土壤中。

dingrhan

我看到这题时的瞬间反应也是选D。 E是后来为雄辩地说服自己D的不可争议性。 考试时，没那么多时间，也只能D了。