[求助]GWD6-Q14问道加强题，谢谢大家！

烦请大家指教为什么D能起到加强作用呢？？我真没想明白··

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Mayor Delmont’s critics（评论家） 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（薪水） 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.[C1] 
2. Average pay in the city was at a ten-year low when Mayor Delmont took office.[C2] 
3. Some of the jobs created in the city during Mayor Delmont’s tenure have in the meantime been eliminated again.[C3] 
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.[C4] 
5. The average pay for jobs in the city is currently higher than it is for jobs in the suburbs surrounding the city.[C5] 

增加的工作的薪水上升，去除的工作的薪水如何才能保证整体平均薪水上升，D给出了答案

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.

在Delmon任內

(1) 新創的工作比消失的工作多

(2) 新創的工作平均薪資比全市的平均薪資高

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

A.      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.

      過去三年的新創工作平均薪資比Delmont任期新創的平均薪資工作高

      並沒有加強因Delmont擔任市長使新創平均薪資比全市高>>>不選

B.       Average pay in the city was at a ten-year low when Mayor Delmont took office.

      沒有加強上述兩點

C.      Some of the jobs created in the city during Mayor Delmont’s tenure have in the meantime been eliminated again.

      沒有加強上述兩點

D.      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.

      消失的工作的平均薪資與全市平均薪資大致相當>>加強

      E.       The average pay for jobs in the city is currently higher than it is for jobs in the suburbs surrounding the city. 無關

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