问题补充:
Nothing that he suggested to be of any use.
A. prove
B. proved
C. proving
D. has been proved
答案:
A. prove
(答案→)B. proved
C. proving
D. has been proved
解析:句意:他提的建议证明对我们没有用。这里he suggested是定语从句,整个句子的主语是nothing,所以这里缺少谓语动词;根据suggested判断谓语动词应该用过去式,故选B。