GWD9-Q3

3)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.

A.    Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people

B.    As the cost of wireless service plummeted in the last year and as mobile phones became increasingly common, many people

C.    In the last year, with the cost of wireless service plummeting, and mobile phones have become increasingly common, there are many people

D.    With the cost of wireless service plummeting in the last year and mobile phones becoming increasingly common, many people are

E.     While the cost of wireless service has plummeted in the last year and mobile phones are increasingly common, many people are

请教下，这道题答案是E吗？如果是E的话，我有一个问题就是，在while从句中，in the last year存在情况下用了现在完成时，这样可以吗？难道in the last year用现在完成时，而last year则是一般过去时的标志呢？请nn多多指教：）反正in the past 5 years之类的是应该用完成时的。

It's easy to eliminate A,B,and C.

Left D and E, D is too awkward when it says with the phones becoming increasingly common,

so E wins.

I won't think too much about whether the in the last year is right.

Still E

D is not right.

While in E means when, not comparison here.

plummeting in the last year is right, that means it's still plummeting, but it's already finished.

I still think E is right.

阿3的解释错了，答案是E无异议。

汗颜ing。现在理解了D确实比E好，一时草率轻狂，见谅：）谢谢指教：）

这个是新PREP里面的，答案是D没错的。

E，while表达了转折的含义，而文章没有这层意思。

我想问下B是不是因为第二个as是多余的所以错了？

补充一点疑惑，一直认为become是短暂性动词，不可以用ing形式，有这种说法吗？