Question

【题目】____ several times, the young scientist still kept on doing his experiments.

A. Having failed B. Having been failed

C. Failed D. To fail

Answer 1

【答案】A

【解析】分词动作fail与其逻辑主语the young scientist之间是主动关系，故用现在分词作时间状语，又因为现在分词的动作发生在谓语动作之前，故用现在分词的完成时。