标题: GWN-TN-19 各位大神解释下啊 [打印本页] 作者: ssysyjzmf 时间: 2012-6-17 23:10 标题: GWN-TN-19 各位大神解释下啊 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 这道题的hypothesis 指的是therefore后面的吗，如果不是的话，指的是什么呢
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 ______.