语法与词汇 18.—David is said to be the first young teacher professor in your university this year. —Exactly, ______of his own competence is an important factor in his success.

A、 to convince
B、 convincing
C、 convinced
D、 convince

【正确答案】 C

【答案解析】be convinced of sth．“对……有信心”，being convinced of his own competence是动名词短语做主语，故选C。