— What's the matter with the man hanging his head there?— Well, if you _____ know, he was caught stealing my bike. 

Some young people these days just ______ go out of their homes to contact the real world．

．—Do you feel like ________ there or shall we take a bus? 　　  —I’d like to walk. But since there isn't much time left, I'd rather we________ a taxi. 

Thank you very much. Without your help we ______ car started.

It's everybody's desire that  every effort___________to reduce the pollution in our city.