问题
选择题
_____many times, they succeeded _________ the experiment.
A．Having tried; in doing
B．Tried; in being done
C．Having tried; to do
D．Tried; doing
答案
答案：A
考查非谓语动词。主语they与try之间是主动关系，故用现在分词。分词的动作发生在谓语动词之前，所以用现在分词的完成式，短语：succeed in doing sth 成功做成某事，句意：尝试了许多次之后，他们成功的做成了实验。所以选A。