[已解决]请教一道PREP的逻辑题~~并且附上高智威老师PREP的详解

carvinhuang

Most of the world's supply of uranium currently comes from mines.It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that uranium fetches on the world market.Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.

Which of the following would it be most useful to determine in evaluating the argument

(A) Whether the uranium in deposits on land is rapidly being depleted

(B) Whether most uranium is used near where it is mined

(C) Whether there are any technological advances that show promise of reducing the cost of extracting uranium from seawater

(D) Whether the total amount of uranium in seawater is significantly greater than the total amount of uranium on land

(E) Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater

正确答案：A
以下是高智威老师的解释：
思考：1. 文中告诉我们，是否“this method is unlikely to be commercially viable”，主要是比较uranium from seawater 和 uranium on the world market (uranium from mines),谁的成本比较高（也就是原因）。换句话说，from seawater的成本高，那就commercially viable, 否则不是；2. 所以，正确答案一定与原因相关，并且不能有无关名词。

我的疑问：
1、请问highlight蓝色部分是什么意思？有人能帮我翻译一下这句话吗？
2、highlight绿色部分不懂，这个方法是否可行，关键不是在于cost of extracting uranium from seawater can somehow be reduced，为什么要两个比较，才能得出这个方法是否可行？！

(B) Whether most uranium is used near where it is mined

(C) Whether there are any technological advances that show promise of reducing the cost of extracting uranium from seawater

(D) Whether the total amount of uranium in seawater is significantly greater than the total amount of uranium on land

(E) Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater

正确答案：A
以下是高智威老师的解释：
思考：1. 文中告诉我们，是否“this method is unlikely to be commercially viable”，主要是比较uranium from seawater 和 uranium on the world market (uranium from mines),谁的成本比较高（也就是原因）。换句话说，from seawater的成本高，那就commercially viable, 否则不是；2. 所以，正确答案一定与原因相关，并且不能有无关名词。

我的疑问：
1、请问highlight蓝色部分是什么意思？有人能帮我翻译一下这句话吗？
2、highlight绿色部分不懂，这个方法是否可行，关键不是在于cost of extracting uranium from seawater can somehow be reduced，为什么要两个比较，才能得出这个方法是否可行？！

(A) Whether the uranium in deposits on land is rapidly being depleted

(B) Whether most uranium is used near where it is mined

(C) Whether there are any technological advances that show promise of reducing the cost of extracting uranium from seawater

(D) Whether the total amount of uranium in seawater is significantly greater than the total amount of uranium on land

(E) Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater

正确答案：A
以下是高智威老师的解释：
思考：1. 文中告诉我们，是否“this method is unlikely to be commercially viable”，主要是比较uranium from seawater 和 uranium on the world market (uranium from mines),谁的成本比较高（也就是原因）。换句话说，from seawater的成本高，那就commercially viable, 否则不是；2. 所以，正确答案一定与原因相关，并且不能有无关名词。

我的疑问：
1、请问highlight蓝色部分是什么意思？有人能帮我翻译一下这句话吗？
2、highlight绿色部分不懂，这个方法是否可行，关键不是在于cost of extracting uranium from seawater can somehow be reduced，为什么要两个比较，才能得出这个方法是否可行？！

sdcar2010

Not A until B

Logic chain:
A --> B
If A, then B.  B is the necessary condition for A to happen. A is the sufficient condition for B to result in.

哥大千里马

蓝色部分翻译：因此，除非这种从海水里提取u物质的成本能够通过某种方法降下来，否则这种获得u物质的方法将没有商业价值
题中说获得U有两种方法：1 从海水中提取 2 从mines中获得，但是从海水中获得成本太高以至于没有商业价值，也就是说是否有商业价值主要从两种方法的成本高低来看，那个成本低，哪个就有商业价值
A选项说u被迅速耗光，那么从mines获得U的成本将大幅增高，因此就可以评价哪个更有商业价值

Doriskk

求老师的详解！