It is reported that the railway now will cut the journey time between the two cities by a

问题补充：

It is reported that the railway now will cut the journey time between the two cities by about 12 hours.

A. built

B. to be built

C. having built

D. being built

答案：

A. built

B. to be built

C. having built

(答案→)D. being built

解析：本题考查非谓语动词。根据语境可知铁路正在被建造，故用being built作定语，修饰the railway。句意：据报道，现在正在被建造的铁路将缩短2个城市旅行时间大约12小时。