—It's difficult for the village children to cross the river for school.

—I think a bridge _______ over the river. [ ]

A. should be built

B. is being built

C. has been built

D. was built

和项目前评估相比，后评价的最大特点是( )。

A．信息的独立

B．信息获取快

C．信息的准确

D．信息的反馈