The suggestion they all objected to to be effective finally.
A. proving
B. prove
C. had proved
D. proved
网友回答
A. proving
B. prove
C. had proved
(答案→)D. proved
解析:考察时态.句意,他们都反对的建议最后证明是有效的. they all objected to作定语修饰suggestion,句子主语为suggestion,根据finally,可知句子强调的是过去发生的动作,故用过去时态,选D.