对答案产生疑问

GabrielHong

In Kravonia, the average salary for jobs requiring a college degree has always been higher than the average salary for jobs that do not require a degree. Current enrollments in Kravonia’s colleges indicate that over the next four years the percentage of the Kravonian workforce with college degree will increase dramatically. Therefore, the average salary for all workers in Kravonia is likely to increase over the next four years.
Scarcity=缺乏，不足
Which of the following is an assumption on which the argument depends?
A.    Kravonians with more than one college degree earn more, on average, than do Kravonians with only one college degree.
B.    The percentage of Kravonians who attend college in order to earn higher salaries is higher now than it was several years ago.
C.    The higher average salary for jobs requiring a college degree is not due largely to a scarcity among the Kravonian workforce of people with a college degree.
D.    The average salary in Kravonia for jobs that do not require a college degree will not increase over the next four years.
E.    Few members of the Kravonian workforce earned their degrees in other countries.
给的答案是c，我觉得答案是D。

云南

选D是肯定不对的，因为D中说没有文凭的平均工资没有上升不能支持论点，我们也不能断定没有文凭的平均工资是否上涨

jczephyr

读完段子和问题，最有可能想到的假设应该和两类工作岗位的数量关系有关，但答案C给出了一个供求关系和价格的补充说明，间接说明higher salary不会下降，假设成立。

GabrielHong

我现在懂了，如果对c选项取非，那么有大学文凭的人的工资高是因为其稀少，那么现在大学文凭的人多了，他们的工资就不会高了，所以对argument造成了削弱，因此是真确答案。反观D选项，对其去非，如果没有大学文凭的人的工资增加的话，总的平均工资也会增加，没有对argument造成削弱，因此不是正确答案。