51. --- Who is at the _____ of all this trouble. --- I don’t know.
Grandma pointed to the hospital and said, "That's ______ I was born."
She'd lived in London and Manchester, but she liked ______ and moved to Cambridge.
A company ______profits from home markets are declining may seek opportunities abroad.
It’s standard practice for a company like this one______ a security officer.
—Is Anne coming tomorrow? —_____.If she were to come, she would have called me.