以下是引用howardwang在2005-9-22 9:00:00的发言: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 ______. C: others of the closely related group of plants are also found to produce histidine in large quantities 从C可以得出,这类植物都有一个共同点。 当一类事物中有一个共同点(而且已经证明,这类事物中的一个事物的该共同点对事物的特征有作用,即: large amounts of histidine, an amino acid that, in test-tube solutions, renders these metals chemically inert.),且这类事物表现出一个共同的特征(a group of closely related plants that thrive in soil with high concentrations of metals that are toxic to most other plants.)。 那么,你能推出什么呢? 可能就是这个共同点造成了这个共同的特征。所以支持结论。
呵~ 大家心平氣和地討論阿...偶們共同的敵人只有一個,那就是ETS
howardwang兄分析得很透徹,也把支持C的理由清楚地呈現出來。
如果把C選項取非,這種植物的其他家族不製造histidine這咚咚卻也能在充滿重金屬的土地中生存,表示其生存的能力並非來自histidine,亦削弱了本題論點中的假設。反過來說,C成立的話也將加強該假設的力度。
大家繼續討論 ^^ |