– It’s difficult for the village children to cross the river to get to school.
– We think a bridge over the river.
A. was built
B. should be built
C. has been built
D. is being built
网友回答
A. was built
(答案→)B. should be built
C. has been built
D. is being built
解析：根据句意“对于乡村的孩子来说，穿过那条河去上学是困难的。”“我们认为，应该在河上修一座桥。”A、C、D的时态不符，B项符合题意。故选B。