– It’s difficult for the village children to cross the river to get to school.– We think a

问题补充：

– 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

答案：

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。