It is reported that the underground systemin Changsha now will be open in .A. is being

问题补充：

It is reported that the underground systemin Changsha now will be open in .

A. is being built

B. built

C. being built

D. is built

答案：

A. is being built

B. built

(答案→)C. being built

D. is built

解析：考查非谓语动词。句中being built in Changsha now现在在长沙被建，在句中作定语，修饰the underground system，故选C。