There was so serious a matter that I had no choice but _________ the police.
___________his work, he went back to work after supper.
When I got back home I saw a message pinned to the door_____ “Sorry to miss you, will call later.”
The reading room is_______the classroom.
Rather than________on a crowded bus, he always prefers___________a bicycle.
The salesman scolded the girl caught_______and let her off.