Most of us still wonder ___________ it is ________ makes those honest peasant workers, without being paid at all, resign themselves to the bosses.

Lin Dan’s success_______ all the Chinese. We believe that he can do better in the 2016 Olympics.

I don’t know the homework ______ today. [ ]

Some young people in America are expected to leave ______ could be life’s most important decision—marriage— entirely up to luck.

He ran the 100 meters in 9.91 seconds, and I have not seen _________ this year.