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板凳
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发表于 2015-12-10 21:14:02
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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
In evaluating the argument, it would be most important to determine which of the following?
A.Whether the herb can thrive in soil that does not have high concentrations of the toxic metals
B.Whether others of the closely related group of plants also produce histidine in large quantities
C.Whether the herb's high level of histidine production is associated with an unusually low level of production of some other amino acid
D.Whether growing the herb in soil with high concentrations of metals will, over time, reduce their concentrations in the soil
E. Whether the concentration of histidine in the growing herb declines as the plant approaches maturity
OG答案:B 解释:If the closely related plants do not produce much histidine, whatever other factor allows them to thrive in metal-rich soil would likely account for why the herb thrives in those soils as well. |
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