—Mr . Smith was really helpful when you were in financial difficulty during those years. —Definitely . I can never appreciate his kindness .
He wrote to his friends ______ information.
Old McDonald gave up smoking for a while, but soon _____ to his old way.
What _____ to Joan last night? What did she cry for?
_____ is the population of your country?
Please say "Hi" to Bob ______ me.