GWD19-3困惑

Q3（问问问）:

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(为啥错了)

e貌似没有任何毛病啊，困惑。。。

E,  has plummeted in the last year 时态。

总觉得白勇是指 in the last\past + number + years, 不知是不是？

in the last year 和 last year 有什么区别阿

我觉得while强调的是并列关系，with的表达更能反映因果关系。而且with没有歧义，用with更简洁。

请大家指正！

（1）E的错误主要在于其结构：“While…, many people are now using their mobile phones to make calls across a wide region at night and on weekends, when….”
                

（2）其次，在逻辑关系上，真正让人们用手机在晚上和周末打垮区域电话的原因是“numerous wireless companies provide unlimited airtime for a relatively small monthly fee”，显然，由于此前wireless companies可能把“晚上和周末”认为是黄金时间而收取黄金价格，人们被迫在白天和工作日通话。因此，原句要强调的是这样的一个变化。至于服务费下跌和手机的普遍性，则仅是让原句逻辑结构完整，否则会遗留不必要的assumption。所以用“with”带出更为合适。

while+从句，表示强烈的对比，在这里明显是因果关系，所以E不对

只能D

in the last year是用现在完成时，但这句话的考点不是这里。

这题目有两个考点：1。people要有主谓结构。

                  2。and对称，E一个是现在完成时，一个是现在进行时，显然不对称。答案是D