GMAT考题：OG2016-CR-100

GMAT考题

题库 / OG2016-CR-100

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 growth of this herb have discovered that it produces large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert. Hence, the herb's high histidine production must be the key feature that allows it to grow in metal-rich soils.

In evaluating the argument, it would be most important to determine which of the following?

Whether the herb can thrive in soil that does not have high concentrations of the toxic metals

Whether others of the closely related group of plants also produce histidine in large quantities

Whether the herb's high level of histidine production is associated with an unusually low level of production of some other amino acid

Whether growing the herb in soil with high concentrations of the metals will, over time, reduce their concentrations in the soil

Whether the concentration of histidine in the growing herb declines as the plant approaches maturity

考题讲解

毕出

情景：一种草药可以在重金属土壤中存活。研究表明这种草药中含有一种大量的可以让金属呈现惰性的物质组氨酸。因此，是组氨酸导致了这种草药可以在土壤中存活。

推理：前提中“组氨酸”和“草药可以在重金属土壤中存活”具有统计关联，结论中两者出现因果关系，因此本题为相关因果推理。推理结构为：
前提：“组氨酸”和“草药可以在重金属土壤中存活”具有正相关关系
结论：组氨酸导致了这种草药可以在土壤中存活

选题方式：相关因果推理有四个评估方向，简而言之，即，答案选项要么同时提及“组氨酸”和“草药可以在重金属土壤中存活”，要么给“草药可以在重金属土壤中存活”另一个原因。

选项分析：

A选项：这种草药能否在不含有重金属的土壤中存活？本选项没有提及推理文段中的因果。

B选项：Correct. 其他的能存活在重金属土壤中的植物是否也生产这种组氨酸？本选项同时提到了因果，即，若别的能存活在重金属土壤中的植物不产生这种组氨酸，则证明“组氨酸”和“草药可以在重金属土壤中存活”是无关的（换了一种植物，写明因在果不在）。属于CQ1：相关性存在问题。

C选项：这种草药的高量的组氨酸是否和低量的其它酸有联系？本选项没有提及推理文段中的因果。

D选项：把这种草药放在重金属土壤中是否将会减少土壤中的重金属含量？无论草药是否能进化土壤，我们都只能证明草药确实可以适应这样的土壤，依然不知道究竟是什么原因让这种草药存活的。

E选项：在这种植物达到成熟时，是否组氨酸的量会下降？本选项只提到了组氨酸，没有提到原文中的果。