Did you have any trouble ____ the post office?
______ the room, the nurse found the tape-recorder ______ .
The women kept her eyes _____ on her baby for quite some time.
____ is known to all, China will be an _____ and powerful country in 20 or 30 years’ time.
You can’t take the lift because it is _______.
After cooking, Mother ___________ making tea.