推 chenemily:TKS 07/27 12:38
推 danyuchn: 07/27 12:46
※ 編輯: dounts 來自: 115.80.25.191 (07/27 12:49)
※ 引述《chenemily (天天保持好心情)》之銘言：
: 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
: 請問一下這題 對於C 我不知道該用怎麼方法刪除
: 感覺好像對
以下略過 這題的意思是
除非擷取 uranium 的成本減低
(until 有點像是除非的意思)
否則這方法不會有經濟上的可行性
所以因果關係 (argument) 已經確定
"the cost of extracting uranium from seawater can somehow be reduced"
這個已經成為了假設成立的事實了 就無須用 (C) 來討論可行性
而我們要討論的是 是否成本一定要降低才會有可行性
而非成本是否可以降低 所以排除 (C) 選項選 (A)
當陸地上的 uranium 都沒有之後
不管成本是否降低 都得從海水擷取
: cost 下降 ---> uraniumis likely to be commercially viable
: 然後我看了Ron大神的說法 不是很懂
: the argument says
: until the cost of extracting uranium from seawater can somehow be reduced,
: this method of obtaining uranium is unlikely to be commercially viable.
: in other words, the argument is saying that the ONLY WAY that seawater
: extraction will be commercially viable is if the cost of that extraction
: comes down
: choice (c) doesn't actually affect the argument at all, because the argument
: already acknowledges that uranium will become commercially viable IF the
: price comes down.
: 我有點暈暈的 有人可以解釋一下嗎
: 感謝
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◆ From: 115.80.25.191
※ 編輯: dounts 來自: 115.80.25.191 (07/27 12:30)