—It’s difficult to get to the other side of the river.—I think a bridgeover the river.A. s

问题补充：

—It’s difficult to get to the other side of the river.

—I think a bridgeover the river.

A. should be built

B. should build

C. will build

D. has built

答案：

(答案→)A. should be built

B. should build

C. will build

D. has built

解析：句意：很难到河的另一边。——我认为应该在河上建一座桥。结合语境可知下文从句描述是客观性动作，故用一般现在时态。从句主语是动作对象，故从句中用被动语态。选A。