死活不明白的LSAT-6-CR2-15

snow_mountain

Twenty years ago the Republic of Rosinia produced nearly 100 million tons of potatoes, but last year the harvest barely reached 60 million tons. Agricultural researchers, who have failed to develop new higher yielding strains of potatoes, are to blame for this decrease, since they have been concerned only with their own research and not with the needs of Rosinia.
Which one of the following is an assumption on which the argument depends?
(A) Any current attempts by agricultural researchers to develop higher-yielding potato strains are futile.
(B) Strains of potatoes most commonly grown in Rosinia could not have produced the yields last year than they once did.
(C) Agricultural researchers often find concrete solutions to practical problems when investigating seemingly unrelated questions.
(D) Wide fluctuations in the size of the potato crop over a twenty-year period are not unusual.
(E) Agricultural research in Rosinia is funded by government grants

答案，选B。 看了前人的解释，居然死活没搞懂。不明白为什么对B取非，结论就不成立。

我的理解是：因为20年前土豆产量是100，去年是60，由这个事实推出结论，应该责备科研人员，因为他们只关心科研，不关系人们的需要，没有开发出高产的新品种。

这好像跟B说的没什么关系嘛？

xiang_y

对B取非: Strains of potatoes most commonly grown in Rosinia could have produced the yields last year than they once did. 说明去年土豆产量下降是别的原因造成的， 错不在strains of potatoes, 自然错也就不在researcher, 与原文结论相反。

snow_mountain

可是这样的话，如果对D取非，说   Wide fluctuations in the size of the potato crop over a twenty-year period are unusual。

这么不寻常的事件发生，也不能怪科研人员呀？

linnasun

对D取非，Wide fluctuations in the size of the potato crop over a twenty-year period are unusual。  说明 common strains of potatoes 本身一般不会出现产量大幅减少问题，那么并不能排除是Agricultural researcher 的问题呀，应该不是weaken 吧。

xiang_y

以下是引用bryony在2003-11-23 18:30:00的发言：
可是这样的话，如果对D取非，说   Wide fluctuations in the size of the potato crop over a twenty-year period are unusual。

这么不寻常的事件发生，也不能怪科研人员呀？

正因为不寻常的减产发生在去年，更说明是strains的原因，也就是researcher的问题。如果产量变化经常发生，那去年减产也就没什么奇怪，更不会怪到researcher.

snow_mountain

我本来理解是，如果不寻常就是其它原因造成的，比如天气什么的。不过现在已经想明白了。

谢谢各位。

zxppx

Twenty years ago the Republic of Rosinia produced nearly 100 million tons of potatoes, but last year the harvest barely reached 60 million tons. Agricultural researchers, who have failed to develop new higher yielding strains of potatoes, are to blame for this decrease, since they have been concerned only with their own research and not with the needs of Rosinia.
Which one of the following is an assumption on which the argument depends?
(A) Any current attempts by agricultural researchers to develop higher-yielding potato strains are futile.
“取非”，即使有一部分现在的努力是有用的，但是不能说明他们过去的问题，无法削弱（注意文中的现在完成时态）
(B) Strains of potatoes most commonly grown in Rosinia could not have produced the yields last year that they once did.
“取非”，如果他们能够恢复过去的产量，那么削弱结论
(C) Agricultural researchers often find concrete solutions to practical problems when investigating seemingly unrelated questions.
(D) Wide fluctuations in the size of the potato crop over a twenty-year period are not unusual.（B）
(E) Agricultural research in Rosinia is funded by government grants.