Since production has risen ________, the personal income has increased year by year.

The U.S. official said North Korea --- and Iran --- should follow in the steps of Libya, which last December said it would work__________ to allow international weapons inspectors to do their work. 

I have little doubt about his competence; ______, he is well-qualified for the job. 

So hard did he work that he __________made himself ill for a whole week. 

In the good care of the nurses, the boy is_____ recovering from his heart operation.