问题补充：
He felt to work for human rights and progress.
A. it his duty
B. his duty
C. that is a duty
D. that is his duty
答案：
(答案→)A. it his duty
B. his duty
C. that is a duty
D. that is his duty
解析：feel/ find/ think / consider/ make/ regard…+ it +名词/ 形容词 +不定式短语,其中it做形式宾语，真正的宾语是“to work for human rights and progress”
