问题
选择题
--- 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
答案
答案：A
由题意判断是桥还没建起来。B C D 的意思是 建起来了 A 应该被建，但还没建