※ 引述《heystranger (卍曠世巨魯霸氣登台卍)》之銘言： : Electric utilities pay less for low-quality coal per ton delivered than for : high-quality coal. Yet more low-quality coalthan high-quality coal must be : burned to generate the same amount of electricity. Moreover, per ton of coal : burned,low-quality coal generates more ash than does high-quality coal, and : the disposal of ash is becoming more and more expensive. : The considerations above, if true, most strongly support which of : the following claims? : (A) A coal-burning utility might not be assured of benefiting economically : by always adhering to the policy of keeping its overall coal purchasing : costs as low as possible. : (B) In those regions where the cost of disposing of coal ash is negligible, : it is more expensive for coal-burning utilities to use high-quality : coal than low-quality coal. : (C) Transportation costs represent a smaller proportion of the cost per : delivered ton for low-quality coal than for high-quality coal. : (D) It is no less expensive to dispose of a ton of coal ash that results : from the burning of high-quality coal than it is to dispose of a ton of : coal ash that results from the burning of low-quality coal. : (E) In regions where coal-ash disposal is the least expensive, reserves of : low-quality coal are likely to decline at a faster rate than are : reserves of high-quality coal. 在處理 coal disposal 最便宜的 "地區" 並沒有翻轉題目的事實: coal disposal cost: low quality coal > high quality coal 所以無法確認 low quality coal 是否會較快消耗 : --------------------------------------------------------------------------- : 小弟資質愚鈍不解答案為何是A，這題做了快10分鐘...超難選擇答案最後選了E : 再回過頭看A，我的理解A:購買低成本無法保證帶來經濟利益(不知道這大意對不對) : 可是原文我找不到一個conclusion明確表明low quality就是不實用 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 題目就是要請你推結論，當然不會明確寫出來 且此題考慮的並不完全是在討論實用性，而是以經濟效率來考慮 : 只有隱性的自己心裡認為這個low quality不實用，與其說support，我怎麼覺得這題更 : 像assumption? 請大大指教! 題目資訊： cost: low quality coal 有優勢 efficiency: high quality coal 有優勢 disposal of ash: high quality coal 有優勢 --> low quality 不見得有經濟上的優勢 (答案 (A)) 我猜想你的疑點大概是，題目並沒有明確指出， high quality coal 和 low quality coal 總成本的優劣 但按照寫作邏輯來看，先提出 low quality coal 的優勢 而後再提其劣勢，並舉出兩點， 當然自然而然得到答案 （A）- low quality coal 不見得有經濟優勢 且 (A) 的答案是相當保守，使用 "might"， 並沒有很武斷的說總成本會較高 這答案當然不是 assumption - assumption 在推理過程屬於"原因"的部分 而此題答案是需要題目條件來"支持" 這樣問吧，你自己覺得是題目 support 答案 (drawn conclusion)， 還是答案 (assumption) support 題目? 我想前者應該更符合一般思考的邏輯 -- Donz 2015 12月全科機經班: http://goo.gl/VwO4yJ Donz + Keewee 速成實力寒假班: http://ndxica.pixnet.net/blog/post/40937209 Donz GMAT FB: https://www.facebook.com/groups/DonzGMAT --

※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 1.161.139.131 ※ 文章網址: https://webptt.com/m.aspx?n=bbs/GMAT/M.1448237556.A.A91.html ※ 編輯: ndxica (1.161.139.131), 11/23/2015 08:18:35 ※ 編輯: ndxica (1.34.44.231), 03/22/2016 11:28:08