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.
Because of wireless service costs plummeting in the last year, and as mobile phones are increasingly common, many people
As the cost of wireless service plummeted in the last year and as mobile phones became increasingly common, many people
In the last year, with the cost of wireless service plummeting, and mobile phones have become increasingly common, there are many people
With the cost of wireless service plummeting in the last year and mobile phones becoming increasingly common, many people are
While the cost of wireless service has plummeted in the last year and mobile phones are increasingly common, many people are
E相较其它选项是最好的.但为什么有明显的the last year 时要用现在完成时has plummeted?
现在完成时表示从过去某时开始的一个动作或状态一直持续到现在,并且有继续持续到将来的可能.它常与状语: just,already, yet,ever,never, for two years,since 1973, in the last decade, in the past ten years, recently等连用.