天山－3－37 难倒我了

lypwilliam

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.
答案是B，题目里说了，最后算下来新方法比旧方法成本要高，B选项怎么能解释新方法会被采用呢？我觉得应该解释为什么一个成本高的方法却能够得到采用。B说使用过新方法的地能卖个好价钱，那我要是用旧方法，岂不是赚的更多？怎么能解释新方法会被广泛使用呢？

请高人指点呀！

beautywawa

for your reference

http://forum.chasedream.com/dispbbs.asp?boardID=24&ID=83550&page=3

lypwilliam

可惜我是看了他们的讨论依然不懂才问的，再看还是不懂啊！谁能给我解释解释

G-CRACKER

新方法是一步到位提炼出nickel, 旧方法有两步：mining + refining. 新方法只比mining成本高一点点。所以新方法还是省银子的。。。

lypwilliam

明白了 多谢楼上高人！