Insect infestations in certain cotton-growing regions of the world have caused dramatic increases in the price of cotton on the world market. Knowing that cotton plants mature quickly, many soybean growers in Ortovia plan to cease growing soybeans, the price of which has long been stable, and to begin raising cotton instead, thereby taking advantage of the high price of cotton to increase their income significantly at least over the next several years.
Which of the following, if true, most calls into question the reasoning on which the plan is based?
The cost of raising soybeans has increased significantly over the past several years and is expected to continue to climb.
Tests of a newly developed, inexpensive pesticide have shown it to be both environmentally safe and effective against the insects that have infected cotton crops.
In the past several years, there has been no sharp increase in the demand for cotton and for goods made out of cotton.
Many consumers consider cotton cloth a necessity rather than a luxury and would be willing to pay significantly higher prices for cotton goods than they currently pay.
The species of insect that has infested cotton plants has never been known to attack soybean plants.
情景:大豆价格一直比较稳定,但是最近棉花的价格由于害虫的侵袭而上涨迅速。所以,为了利用这次棉花价格上升的机会,大豆种植者打算种植棉花。
推理:
目标:为了利用这次棉花价格上升的机会提高收入。
方案:大豆种植者打算种植棉花。
答案预估:
选项需要考虑到方案的可行性,可操作性,以及否定性副作用。
选项分析:
A选项:种植大豆的成本在最近几年显著上升而且预期会继续上涨。本选项和棉花的价格以及种植棉花无关,可以排除。
B选项:Correct. 对新发明的,便宜的杀虫剂的测试表明这种杀虫剂可以在不对环境造成伤害前提下有效的杀掉棉花害虫。如果有这样一种杀虫剂,则很快棉花将不再缺乏,由此使得现在供不应求的情况逆转,棉花将不再有高价,影响到了方案的可行性(即,种了棉花也无法提高收入)。
C选项:在过去的几年中,对于棉花和棉制品的需求并没有显著的上升。虽然需求没有显著增加,但是由于棉花价格在上涨,所以无论需求是否增加,都会增加棉花种植者的收入。本选项不会影响结论的可信度。
D选项:许多顾客认为棉制衣物是必需品而非奢侈品且愿意花更高比现在更高的价格来买棉衣。本选项和C项比较相似。棉花的价格已经由于虫害而变高。无论顾客愿不愿意花更多钱买,变化的仅仅是令价格是否会更高。只要高了,就可以令原文的结论成立,所以本选项并不能影响结论的可信度。
E选项:影响棉花的害虫到目前为止从来不会攻击大豆植物。本选项和棉花的价格以及种植棉花无关,可以排除。
Helr大神看这里!我认为C选项是可以的,因为棉花需求没有上涨,所以如果有更多的人来种植棉花,棉花产量就会提高。结果导致供给增加,利润下降
做任何CR都不能有自己的二次推论,因为你的推论都是建立在假设之上。除非你的推论是选项描述的唯一必要条件,否则任何这种推论都是无效的。你没有办法保证事情一定按照你“假设”的情况发生(因为其不是唯一必要条件),如果事情按照“都买出去了”发生呢?这个选项还能起到你希望的削弱作用了吗?(转自CD论坛)
B 也二次推理了呀,毕竟只是说了有这么种杀虫剂,具体会不会被用到实际中,还是未知;但就本题而言:进一步假设它会被应用到实际
C 算是看明白了,人家说的是过去几年;不是预测将来几年!!!这才是正解,过去的情况跟我将来P点关系都没
登录 或 注册 后可以参加讨论