问题补充：
It is said that another new underground train not far from the center of the city.
A. is to be built
B. has built
C. is to build
D. be built
答案：
(答案→)A. is to be built
B. has built
C. is to build
D. be built
解析：本题需要的是被动语态，因此排除BC，而D前应该有加be动词原形的词，可是没有，是动词不定式的被动语态，故选A
