[求助]请帮助解答GWD6-Q14

GWD6-Q14:

Political Advertisement:

Mayor Delmont’s critics complain about the jobs that were lost in the city under Delmont’s leadership.  Yet the fact is that not only were more jobs created than were eliminated, but the average pay for these new jobs has been higher than the average pay for jobs citywide every year since Delmont took office.  So there can be no question that throughout Delmont’s tenure the average paycheck in this city has been getting steadily bigger.

Which of the following, if true, most strengthens the argument in the advertisement?

1. The average pay for jobs created in the city during the past three years was higher than the average pay for jobs created in the city earlier in Mayor Delmont’s tenure.
2. Average pay in the city was at a ten-year low when Mayor Delmont took office.
3. Some of the jobs created in the city during Mayor Delmont’s tenure have in the meantime been eliminated again.
4. The average pay for jobs eliminated in the city during Mayor Delmont’s tenure has been roughly equal every year to the average pay for jobs citywide.
5. The average pay for jobs in the city is currently higher than it is for jobs in the suburbs surrounding the city.

   Answer: D 请帮助解答，我没想明白，谢谢

D说消失了的工作的工资与全市的平均工资相当。 再看原文，说新工作的工资比消失了的工作的工资高。那么很显然D加强了原文。

数学问题，比如工资是

1,1,2,3,3则平均是2

假设市长去掉了公字是2的工作，增加了5，5的工作

1,1,3,3,5,5则平均是3

以此类推，去掉3，3的工作，加入9，9

则1，1，5，5，9，9平均是5

D加强

D

Line of reasoning:
        工作多了+新工作的工资比市里每年的工作的工资平均水平高 => 总的工资平均水平在上升。

Gap: 总的平均工资水平=(不变的+新生的-eliminated)的工资/job总量

=>那么被eliminated的工作的平均工资水平呢？

要证明这部分不比之前每年的平均工资水平高

A：部分和部分比，不能说明问题，我们要求的总的平均工资水平

B：weaken了

C: out of scope => merely mention the number of jobs, not even mention anything about the pay

E: This argument does not compare the average pay in the city with that of the suburb

D: Correct.