He felt to work for human rights and progress.A. it his dutyB. his dutyC. that is a duty D

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：

A. it his duty

B. his duty

C. that is a duty

D. that is his duty

解析：

此处 it作形式宾语。