Wethink

来源：语文精选馆 2.53W

We think ________ is our duty to make our country a better place.

C．that D．one

解析：题干中________ is our duty to make our country a better place为省略了引导词that的宾语从句，it在从句中作形式主语，真正的主语为后置的不定式短语to make our country a better place。