______ in papers, he didn’t notice my coming.
I can't believe what he says because he is _______ changing his mind. .
Linda had her luggage________ an hour before her plane left.
Could you drive me to the bookstore at noon if________?
In my opinion, it's the flying birds rather than the pilot that________for the air crash.
The teacher didn't like ______composition written by the new student because it didn't make _______ sense.