请教一道GWD题目

gmatziyu

GWD-9-Q3:

Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people now using their mobile phones to make calls across a wide region at night and on weekends, when numerous wireless companies provide unlimited airtime for a relatively small monthly fee.

1. Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people
   
   
2. As the cost of wireless service plummeted in the last year and as mobile phones became increasingly common, many people
   
   
3. In the last year, with the cost of wireless service plummeting, and mobile phones have become increasingly common, there are many people
   
   
4. With the cost of wireless service plummeting in the last year and mobile phones becoming increasingly common, many people are
   
   
5. While the cost of wireless service has plummeted in the last year and mobile phones are increasingly common, many people are
   
   答案是e为什么last year可以用has 呢？d为什么不对呢？
   谢谢！
   
   

venus2elva

D前面的独立主格，主语是many people，不合逻辑，becoming和 increasingly都表示渐进的过程，有点重复吧。

has plummeted in the last year，我也不知道耶，等NN进来

JayNicholas

LS正解    WITH的主语应该是MANY PEOPLE