China a high-speed railway network covering almost all its cities with a population of of more than 500，000 by 2015．
A. is setting up
B. will set up
C. has set up
D. will have set up
网友回答
A. is setting up
B. will set up
C. has set up
(答案→)D. will have set up
解析：句意：中国在2015年为止将已经建成了覆盖所有城市超过50万人口的高铁网络。这句话的时间是by 2015年，介词by一般和完成式连用，2015年是将来的时候，所以用将来完成式，选D。