结构推理他的竞选演讲未能使选民相信他就足参议员的合适人选。(to convince)

【正确答案】His election speech failed to convince the voters that he was the right person for the Senate seat.

【答案解析】[翻译指导] convince可接由that引导的宾语从句，也可以用convince sb. of sth. 结构。fail to do sth. “未能做成某事”。