问一题

cjyc1

GWD: 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.

答案是什么

[此贴子已经被作者于2007-8-4 2:22:18编辑过]

程雅祺

D

程雅祺

对不起，说错了～～～～是C

luoluo1338

d吧？

luoluo1338

还是c

CShadow

我选C。

A: histidine is found in all parts of the plant – roots, stem, leaves, and flowers

  (all parts, 与题目无关)
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

　（other amino acids，无关）
C: others of the closely related group of plants are also found to produce histidine in large quantities

　（如果这类植物都会产生这样的histidine,正说明农学家们是正确的）
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

　（与题干内容相反）
E: the concentration of histidine in the growing herb declines as the plant approaches maturity.

　（out of scope）