_____ the city’s public school system should be open to the children of migrant workers has become the focus of discussion.

During the 1950s，R&.B changed modern music further and led to＿＿＿＿we know as rockand roll.

Being a doctor is one of the few professions＿＿＿＿if you make a mistake，it can mean somebody's life．

When solving the problem a second time, you’d better be more careful ________ you made a mistake.

—What’s your plan for this winter vacation?
—I’ll take an express train to Shanghai for my holiday ___________ school ends.

When I woke up, I found myself lying in ____ was called Red Star Hospital.

________ you prefer, I'll give it to you. But we haven't any other models for you to choose from.

It should be made known to the public _________ the money raised has gone.

_____ cleaning the doghouse was the last thing I wanted to do, I did it with all my efforts.