Do you know the Three Gorges Dam is the largest hydro-electric dam ever ?
A. constructed
B. constructing
C. to be constructed
D. been constructed
网友回答
(答案→)A. constructed
B. constructing
C. to be constructed
D. been constructed
解析：the largest hydro-electric dam与construct之间是被动关系，故用过去分词作定语。