天山4－34

canadianvip

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 degrees will increase dramatically.  Therefore, the average salary for all workers in Kravonia is likely to increase over the next four years. 

Which of the following is an assumption on which the argument depends?

1. Kravonians with more than one college degree earn more, on average, than do Kravonians with only one college degree.
2. The percentage of Kravonians who attend college in order to earn higher salaries is higher now than it was several years ago.
3. 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.
4. The average salary in Kravonia for jobs that do not require a college degree will not increase over the next four years.
5. Few members of the Kravonian workforce earned their degrees in other countries.

我选D，答案是C
我的理解是：假设工作的人里有学位的x人 ，没有的y人，两者的平均工资为a， b，平均工资＝(a*x+b*y)/(x+y),

题中说未来四年有学位的人比重上升==>整体平均工资将上升
也就是题目认为 x/(x+y)==>增加时平均工资增加
要给个假设条件使这个推理成立的话，应该考虑公式里的其他因素的影响。
把D取反的话，就是b 未来会增加，那这样就有他因存在，不能说是有学位的比重多了导致整体工资水平高
因此我认为，D是排除他因假设。

可是我看了大家的讨论贴，对于C的解释我不能理解，我觉得C是排除了引起有学位的人工资上涨的他因，即排除导致a增加的他因，对于结论中的整体工资水平没有涉及，
请指教！！谢谢！

sunnylee

here in this argument ,the author says that since the salary level of person who has college degree is much higher than that of person who has not degree,the salary for all the workforce in country K ,when the number of the predicable graduates from college with degrees will increase dramatically. 

Then the assumption here has two major direction.One is to fill the gap ,the other is to find out the patten ,"not + weaken".

Here in choice C ,we can find that choice C meets the needs of "not + weaken".Now let's express the choice C without "not".The sentence is "The higher average salary for jobs requiring a college degree is due largely to a scarcity among the Kravonian workforce of people with a college degree.".

That means the reason for the fact that salary is so high for the person who has college degree is the amount of such kinds of person is small.And then ,if the amount becomes bigger than ever before ,it's logical to result in the salary level will decrease ,contary to the conclusion made in the argument.

So ,choice C is the best answer.

In choice D,If we do the same as what we did in choice C,relocated the sentence with out "NOT".Then we will found that "The average salary for jobs that do not require a college degree will increase over the next four years".If it is ture and then fortified with average salary for jobs that requires a college degree increase dramtically, the conclusion listed in the argument above will be strengthened not weaken.Then the patten "not + weaken" will be undermined .

So the choice D is not the answer we prefer.