请教三道PREP2（新版）的逻辑CR题目 75 82 83

fay009

75.    (30082-!-item-!-188;#058&004831)

Which of the following, if true, most logically completes the reasoning in the passage?
Kernland’s government restricts the export of unprocessed cashew nuts in order to ensure a low-cost supply for domestic processing plants.  Though the policy constrains farm income and limits the number of farmers who can profitably grow cashews, the government defends it on the grounds that, since the processing plants are in urban areas, removing the restrictions would hurt efforts to reduce urban unemployment.  However, the policy may actually have contributed to urban unemployment, since __________.
A. a lack of profitable crops is driving many small cashew farmers in Kernland off their land and into the cities
B. some of the by-products of cashew processing are used as raw materials by other industries located in Kernland’s cities
C. the government does not place similar restrictions on the export of any crop other than cashews
D. the income earned by workers in the processing plants is generally greater than that earned by agricultural laborers in rural areas
E. without governmental aid in some form, Kernland’s cashew processing plants would not be able to compete for sales in world markets

答案选择A。我想选择B。题目不是说processing plants是在urban么，怎么会导致farmer off land to cities呢？
另外根据B，如果city的生产by-product的需求多了，unemployment不就上升了么~~


82.    (33511-!-item-!-188;#058&007598)

Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade.  However, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars.
Which of the following, if true, does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?
A. The cost of oil has fallen dramatically.
B. The reduction in the cost of solar-power equipment has occurred despite increased raw material costs for that equipment.
C. Technological changes have increased the efficiency of oil-fired power plants.
D. Most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants.
E. When the price of oil increases, reserves of oil not previously worth exploiting become economically viable.


答案是C。

我觉得that is…的意思：为了使solar power更加经济，oil的price应该rise，这样oil-fired的plants就显得不那么经济了
但还是不知道为什么要选择C呢。。



83.    (25338-!-item-!-188;#058&001294)

Many people suffer an allergic reaction to sulfites, including those that are commonly added to wine as preservatives.  However, since there are several winemakers producing wine to which no sulfites are added, those who would like to drink wine but are allergic to sulfites can drink these wines without risking an allergic reaction to sulfites.
Which of the following, if true, most seriously weakens the argument?
A. Sulfites occur naturally in most wine.
B. The sulfites that can produce an allergic reaction are also commonly found in beverages other than wine.
C. Wines without added sulfites tend to be at least moderately expensive.
D. Apart from sulfites, there are other substances commonly present in wine that can trigger allergic reactions.
E. Wine without added sulfites sometimes becomes undrinkable even before the wine is sold to consumers.

A是答案。
我也认同A是答案。但是我觉得E也是有道理的。如果没有加入sulfites就undrinkable的话，那过敏的人不还是不能喝么~望指教~~

钱喵喵

受益匪浅，谢谢解答

Kate200815019

讲得很清楚 谢啦

fay009

了解了～～非常感谢你啊～～

coolhaoming

呵呵，刚查了查，那道题就是咱们在另一个帖子里讨论过的一道，鹿虱子导致风湿病的题（prep新版cr2 100题），B，虱子的数量受限于对幼虫宿主的可利用性，这里虱子和感染了的虱子是不一样的概念，与E有些类似，但是在100题，B是相对好的答案了……而83有更好的，所以选更好的

coolhaoming

83.题干：很多人亚硫酸盐过敏。 因为有些酒里不含亚硫酸盐，因此过敏的人可以喝这种酒。
E：不加亚硫酸盐的酒有时候再没卖之前就不能喝了。楼主注意结论：过敏的人可以喝这种酒。而E则推出都不能喝这种酒。E和题干说的人不是同一种人，相对于A选项E不够适合。如果没有A，E是可以考虑的，等会找到了类似的那道题发上来~
昨晚学校网络太不稳定，没发完就当机了，不好意思啊~

fay009

谢谢楼上同学~~

那请问83题呢~~~

coolhaoming

82.为了让太阳能电站比新型火电站更经济而每桶油增加的价格
在过去10年里，科技进步和设备价格的降低使太阳能直接转换成电能更加划算。
然而太阳能经济可行的阈值却没有改变，保持在35美元。
A油的成本降低了很多
B尽管增加了原材料的成本，太阳能设备成本上降低了。不能说明阈值没有变化，阈值没变主要和传统发电的成本降低有关。
C科技变化增加了油火电的efficiency。
D煤火和核能主要发电，而不是油火电站主要发电。与阈值无关。
E当有的价格增加时，以前不值得储备油现在却可以储备了。

主要在A和C上。根据题意，efficiency与raw materials和equipment的成本都有关系。而A只说明了一个方面，相对来说C更好。
threshold=太阳能efficiency—油火发电efficiency

coolhaoming

75题干：政府限制未加工腰果出口来确保国内低价供应腰果。尽管限制出口会限制农业收入并且限制挣钱种腰果农民的数量。政府辩解说加工腰果的工业在城市，解除限制不能降低城市失业率。但是这个政策还是增加了失业率，因为：
A农民挣不到钱就搬到城市里了。
B加工腰果的副产品是城市其他工业的原材料。所以保护了加工业能够保护其他工业，于是失业率就低了。所以B是错的
C政府没有对其他产品实施出口限制。对本题没有影响，因为题目说的是腰果生产及加工业。
D腰果加工业的工人通常争得比农村的农业工人多。收入问题和失业率无关。
E没有政府帮助，腰果加工不能和世界市场竞争。与失业率无关。
于是只剩了A，农民进城了，如果找到工作还好，而找不到工作的可能性也很大。而原题是However，the policy may actually注意是可能，所以A是可以的。
多多指教