They won't let him out of the hospital ________ he's completely recovered.
The officer gave orders that anyone _____ a gun should be reported to the police station.
----- You seem in low spirits. Anything wrong?----- I ______ in the important exam. I let my parents down.
A wallet has been found and can be ______ the manager’s office.
----- How did you know the surprising news?----- I happened _______ the event then.
If the wound ______ become infected, do not hesitate to call me.