天山-3-37 非常迷人~~~ - ChaseDream

Because mining and refining nickel is costly, researchers have developed an alternative method for extracting nickel using Streptanthus polygaloides, a plant that absorbs and

stores nickel form the soil as it grows. The researchers incinerated a crop of Streptanthus

they grew in nickel-rich soil. By chemically extracting nickel from the ash, they produced 100 pounds of nickel per acre of land at a total cost per pound slightly above that of current mining.

Which of the following, if true, most strongly supports the conclusion that the use of

A. The season in which the researchers grew Streptanthus was an unusually favorable one, with the right amount of precipitation to maximize the growth rate of Streptanthus.

better for agriculture in general, a plot on which Streptanthus has been grown and harvested can be sold for substantially more than it cost.

C. More air pollution is generated for each pound of nickel produced by extracting it from Streptanthus than is generated using conventional mining and refining.

D. The land on which the researchers planted Streptanthus was unusually free of the various weeds that can compete with Streptanthus for water, nutrients, and sunlight.

E. It is extremely rare for soil to contain higher concentrations of nickel than the concentrations present in the researchers’experimental plot.

给出的答案是B，我做的是D。我仔细看答案，后来渐渐明白了。

D. 没有weeds, 就像 A 一样，是 unusually favorable condition, 所以 A, D 就都排除了。

我第一次做的时候都没太敢选B,觉得这个答案似乎太直白了,后来觉得其他的似乎不是很贴边,才选了个B

到底Streptanthus这种植物是种植在nickel-rich soil还是一般的soil…

D是说试验采用的方法太好了，如果实际没那么好，就会提高成本，是削弱项。应为B

做的时候来不及做了，随便选了B；分析的时候，很痛苦的选了E，一对答案，竟然还是B！

无论答案如何，讨论一下解题思路：怎么看B都不想是ETS出的正确选项，除非这道题分值比较低...另外，B还是有无关的感觉（原文中好像并没有提到experiment's process的费用就比current mining的低），因为题干中已经提到slightly above的优势了，再强调其他的经济效益也怎么都不为过。

E有没有可能支持呢:如果土壤中的concentration很少比新实验的方法高，说明新实验的方法没有浪费；否则的话可能存在一个它因削弱：即100pounds的nickle每磅含量高，但其消耗的原土用currrent mining可能产出200pounds的nickle。

原文中好像也并没有提到experiment's process的费用就比current mining的低，好多不确定因素，这题真不知道如何形成严谨的思维。望大家再详细地分析一下，谢谢。

顶一下，因为我也不懂。我当时做的时候时用排除法做的，就B看的云山雾罩，其它的都可以排除。

以下是引用JerryGuan在2004-12-11 1:22:00的发言：

Q37:

Because mining and refining nickel is costly, researchers have developed an alternative method for extracting nickel using Streptanthus
polygaloides, a plant that absorbs and

stores nickel form the soil as it grows. The researchers incinerated a crop of Streptanthus

they grew in nickel-rich soil. By chemically extracting nickel from the ash, they produced 100 pounds of nickel per acre of land at a total cost per pound slightly above that of current mining.

Which of the following, if true, most strongly supports the conclusion that the use of

Streptanthus to extract nickel will be commercially adopted?

A. The season in which the researchers grew Streptanthus was an unusually favorable one, with the right amount of precipitation to maximize the growth rate of Streptanthus.

B. Because lowering the concentration of nickel in the soil can make land much

better for agriculture in general, a plot on which Streptanthus has been grown and harvested can be sold for substantially more than it cost.

C. More air pollution is generated for each pound of nickel produced by extracting it from Streptanthus than is generated using conventional mining and refining.

D. The land on which the researchers planted Streptanthus was unusually free of the various weeds that can compete with Streptanthus for water, nutrients, and sunlight.

E. It is extremely rare for soil to contain higher concentrations of nickel than the concentrations present in the researchers’experimental plot.

这题太迷人了。。。不是因为美丽，而是它总让犯错。

给出的答案是B，我做的是D。我仔细看答案，后来渐渐明白了。

发出来讨论讨论。看看大家的见解。

管兄，我也选了D，关键是没有理解unusually到底表达个什么意思；

正如楼上有人说：“D是说试验采用的方法太好了，如果实际没那么好，就会提高成本，是削弱项。”

題目說用種植S的方法比原來採礦再精練的方法產量其實還比較少題目問怎麼樣可以支持種S讓種S的這個方法是commercially adopted的可以想見既然S方法產量比較少為什麼要支持呢?一定有其他的利益

選項B就是說用s的方法之後土地就會變的更肥沃可以賣更多錢就可以支持了

题目说透过S粹取nickel作为替代方案,但它的成本高于原本方式~

B选说明..因为nickel含量较少有助农作物成长,而使得S长得比较好且卖得比它花费的成本高,可理解will be commercially adopted.

令我不解的是题目整体都在谈论以S作为粹取nickel的替代方案,而选项答案却是说另一方面的议题拿S去卖,赚取利润….

我觉得是关注 commercially adopted, 在经济上可行,其外部性正好表明了这一点,其他选项虽然也有可能加强,但都没关注经济上的问题

以下是引用yaomao在2006-10-8 22:10:00的发言：
这题的选项太神奇了，除了B是支持外，其他都是削弱

E＝》extremely rare SOIL有象实验用的SOIL这么高的含量＝》实验中的结果的cost<实际中的cost＝》新方法cost高＝》削弱

天山CR的题总出现这种题目问得类似脑筋急转弯的问题..........

这条题目ACDE都可以排除掉,都跟原文问"经济上更好"没有关系.可是那个B啊,看的我也是云里雾里,抖着胆子选了它.哈.

看起来考试的时候也要大胆的排除掉无关的选项选那个最有关的,哪怕看得云里雾里的.